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@micromaomao micromaomao commented Nov 23, 2024

PR created for diff viewing purpose. Won't be merging.

Instead of solving a CTF challenge the way you're supposed to, this girl hacked the kernel to brute force it as fast as the code will run...

/*
 * ick: Instant checkpoint
 *
 * Provides a mechanism to "checkpoint" a process at some syscall entry, saving
 * its register and marking its writable memory pages as read-only, such that
 * any attempted writes will cause the current content of these pages to be
 * saved before allowing the write to proceed.
 *
 * At some later point in time, the process can be reverted back to the state
 * when it first made the checkpoint-ing syscall.
 *
 * To simplify the implementation, we only support single-threaded processes,
 * and we do not allow the process to make any syscalls other than read / write
 * to/from stdin/stdout/stderr. We also do not support things like huge pages.
 *
 * This is designed for quick brute-forcing of e.g. CTF binaries. A checkpoint
 * can be made when it first tries reading from stdin for a "password", and then
 * the whole process can be quickly reverted (in a matter of microseconds) to
 * try a different password if the one provided earlier was incorrect, and the
 * process tries to write a message to stdout saying so.
 */

micromaomao pushed a commit that referenced this pull request Nov 24, 2024
…n_net

In the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the
function `nfs4_state_destroy_net` in `nfs4_state_shutdown_net` will
release all resources related to the hashed `nfs4_client`. If the
`nfsd_client_shrinker` is running concurrently, the `expire_client`
function will first unhash this client and then destroy it. This can
lead to the following warning. Additionally, numerous use-after-free
errors may occur as well.

nfsd_client_shrinker         echo 0 > /proc/fs/nfsd/threads

expire_client                nfsd_shutdown_net
  unhash_client                ...
                               nfs4_state_shutdown_net
                                 /* won't wait shrinker exit */
  /*                             cancel_work(&nn->nfsd_shrinker_work)
   * nfsd_file for this          /* won't destroy unhashed client1 */
   * client1 still alive         nfs4_state_destroy_net
   */

                               nfsd_file_cache_shutdown
                                 /* trigger warning */
                                 kmem_cache_destroy(nfsd_file_slab)
                                 kmem_cache_destroy(nfsd_file_mark_slab)
  /* release nfsd_file and mark */
  __destroy_client

====================================================================
BUG nfsd_file (Not tainted): Objects remaining in nfsd_file on
__kmem_cache_shutdown()
--------------------------------------------------------------------
CPU: 4 UID: 0 PID: 764 Comm: sh Not tainted 6.12.0-rc3+ #1

 dump_stack_lvl+0x53/0x70
 slab_err+0xb0/0xf0
 __kmem_cache_shutdown+0x15c/0x310
 kmem_cache_destroy+0x66/0x160
 nfsd_file_cache_shutdown+0xac/0x210 [nfsd]
 nfsd_destroy_serv+0x251/0x2a0 [nfsd]
 nfsd_svc+0x125/0x1e0 [nfsd]
 write_threads+0x16a/0x2a0 [nfsd]
 nfsctl_transaction_write+0x74/0xa0 [nfsd]
 vfs_write+0x1a5/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

====================================================================
BUG nfsd_file_mark (Tainted: G    B   W         ): Objects remaining
nfsd_file_mark on __kmem_cache_shutdown()
--------------------------------------------------------------------

 dump_stack_lvl+0x53/0x70
 slab_err+0xb0/0xf0
 __kmem_cache_shutdown+0x15c/0x310
 kmem_cache_destroy+0x66/0x160
 nfsd_file_cache_shutdown+0xc8/0x210 [nfsd]
 nfsd_destroy_serv+0x251/0x2a0 [nfsd]
 nfsd_svc+0x125/0x1e0 [nfsd]
 write_threads+0x16a/0x2a0 [nfsd]
 nfsctl_transaction_write+0x74/0xa0 [nfsd]
 vfs_write+0x1a5/0x6d0
 ksys_write+0xc1/0x160
 do_syscall_64+0x5f/0x170
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

To resolve this issue, cancel `nfsd_shrinker_work` using synchronous
mode in nfs4_state_shutdown_net.

Fixes: 7c24fa2 ("NFSD: replace delayed_work with work_struct for nfsd_client_shrinker")
Signed-off-by: Yang Erkun <yangerkun@huaweicloud.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
The scmi_dev->name is released prematurely in __scmi_device_destroy(),
which causes slab-use-after-free when accessing scmi_dev->name in
scmi_bus_notifier(). So move the release of scmi_dev->name to
scmi_device_release() to avoid slab-use-after-free.

  |  BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec
  |  Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1
  |
  |  CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1
  |  Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT)
  |  Call trace:
  |   dump_backtrace+0x94/0x114
  |   show_stack+0x18/0x24
  |   dump_stack_lvl+0x48/0x60
  |   print_report+0xf4/0x5b0
  |   kasan_report+0xa4/0xec
  |   __asan_report_load1_noabort+0x20/0x2c
  |   strncmp+0xe4/0xec
  |   scmi_bus_notifier+0x5c/0x54c
  |   notifier_call_chain+0xb4/0x31c
  |   blocking_notifier_call_chain+0x68/0x9c
  |   bus_notify+0x54/0x78
  |   device_del+0x1bc/0x840
  |   device_unregister+0x20/0xb4
  |   __scmi_device_destroy+0xac/0x280
  |   scmi_device_destroy+0x94/0xd0
  |   scmi_chan_setup+0x524/0x750
  |   scmi_probe+0x7fc/0x1508
  |   platform_probe+0xc4/0x19c
  |   really_probe+0x32c/0x99c
  |   __driver_probe_device+0x15c/0x3c4
  |   driver_probe_device+0x5c/0x170
  |   __driver_attach+0x1c8/0x440
  |   bus_for_each_dev+0xf4/0x178
  |   driver_attach+0x3c/0x58
  |   bus_add_driver+0x234/0x4d4
  |   driver_register+0xf4/0x3c0
  |   __platform_driver_register+0x60/0x88
  |   scmi_driver_init+0xb0/0x104
  |   do_one_initcall+0xb4/0x664
  |   kernel_init_freeable+0x3c8/0x894
  |   kernel_init+0x24/0x1e8
  |   ret_from_fork+0x10/0x20
  |
  |  Allocated by task 1:
  |   kasan_save_stack+0x2c/0x54
  |   kasan_set_track+0x2c/0x40
  |   kasan_save_alloc_info+0x24/0x34
  |   __kasan_kmalloc+0xa0/0xb8
  |   __kmalloc_node_track_caller+0x6c/0x104
  |   kstrdup+0x48/0x84
  |   kstrdup_const+0x34/0x40
  |   __scmi_device_create.part.0+0x8c/0x408
  |   scmi_device_create+0x104/0x370
  |   scmi_chan_setup+0x2a0/0x750
  |   scmi_probe+0x7fc/0x1508
  |   platform_probe+0xc4/0x19c
  |   really_probe+0x32c/0x99c
  |   __driver_probe_device+0x15c/0x3c4
  |   driver_probe_device+0x5c/0x170
  |   __driver_attach+0x1c8/0x440
  |   bus_for_each_dev+0xf4/0x178
  |   driver_attach+0x3c/0x58
  |   bus_add_driver+0x234/0x4d4
  |   driver_register+0xf4/0x3c0
  |   __platform_driver_register+0x60/0x88
  |   scmi_driver_init+0xb0/0x104
  |   do_one_initcall+0xb4/0x664
  |   kernel_init_freeable+0x3c8/0x894
  |   kernel_init+0x24/0x1e8
  |   ret_from_fork+0x10/0x20
  |
  |  Freed by task 1:
  |   kasan_save_stack+0x2c/0x54
  |   kasan_set_track+0x2c/0x40
  |   kasan_save_free_info+0x38/0x5c
  |   __kasan_slab_free+0xe8/0x164
  |   __kmem_cache_free+0x11c/0x230
  |   kfree+0x70/0x130
  |   kfree_const+0x20/0x40
  |   __scmi_device_destroy+0x70/0x280
  |   scmi_device_destroy+0x94/0xd0
  |   scmi_chan_setup+0x524/0x750
  |   scmi_probe+0x7fc/0x1508
  |   platform_probe+0xc4/0x19c
  |   really_probe+0x32c/0x99c
  |   __driver_probe_device+0x15c/0x3c4
  |   driver_probe_device+0x5c/0x170
  |   __driver_attach+0x1c8/0x440
  |   bus_for_each_dev+0xf4/0x178
  |   driver_attach+0x3c/0x58
  |   bus_add_driver+0x234/0x4d4
  |   driver_register+0xf4/0x3c0
  |   __platform_driver_register+0x60/0x88
  |   scmi_driver_init+0xb0/0x104
  |   do_one_initcall+0xb4/0x664
  |   kernel_init_freeable+0x3c8/0x894
  |   kernel_init+0x24/0x1e8
  |   ret_from_fork+0x10/0x20

Fixes: ee7a9c9 ("firmware: arm_scmi: Add support for multiple device per protocol")
Signed-off-by: Xinqi Zhang <quic_xinqzhan@quicinc.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Message-Id: <20241016-fix-arm-scmi-slab-use-after-free-v2-1-1783685ef90d@quicinc.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
[BUG]
Syzbot reports the following crash:

  BTRFS info (device loop0 state MCS): disabling free space tree
  BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1)
  BTRFS info (device loop0 state MCS): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2)
  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
  RIP: 0010:backup_super_roots fs/btrfs/disk-io.c:1691 [inline]
  RIP: 0010:write_all_supers+0x97a/0x40f0 fs/btrfs/disk-io.c:4041
  Call Trace:
   <TASK>
   btrfs_commit_transaction+0x1eae/0x3740 fs/btrfs/transaction.c:2530
   btrfs_delete_free_space_tree+0x383/0x730 fs/btrfs/free-space-tree.c:1312
   btrfs_start_pre_rw_mount+0xf28/0x1300 fs/btrfs/disk-io.c:3012
   btrfs_remount_rw fs/btrfs/super.c:1309 [inline]
   btrfs_reconfigure+0xae6/0x2d40 fs/btrfs/super.c:1534
   btrfs_reconfigure_for_mount fs/btrfs/super.c:2020 [inline]
   btrfs_get_tree_subvol fs/btrfs/super.c:2079 [inline]
   btrfs_get_tree+0x918/0x1920 fs/btrfs/super.c:2115
   vfs_get_tree+0x90/0x2b0 fs/super.c:1800
   do_new_mount+0x2be/0xb40 fs/namespace.c:3472
   do_mount fs/namespace.c:3812 [inline]
   __do_sys_mount fs/namespace.c:4020 [inline]
   __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3997
   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
   do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
   entry_SYSCALL_64_after_hwframe+0x77/0x7f

[CAUSE]
To support mounting different subvolume with different RO/RW flags for
the new mount APIs, btrfs introduced two workaround to support this feature:

- Skip mount option/feature checks if we are mounting a different
  subvolume

- Reconfigure the fs to RW if the initial mount is RO

Combining these two, we can have the following sequence:

- Mount the fs ro,rescue=all,clear_cache,space_cache=v1
  rescue=all will mark the fs as hard read-only, so no v2 cache clearing
  will happen.

- Mount a subvolume rw of the same fs.
  We go into btrfs_get_tree_subvol(), but fc_mount() returns EBUSY
  because our new fc is RW, different from the original fs.

  Now we enter btrfs_reconfigure_for_mount(), which switches the RO flag
  first so that we can grab the existing fs_info.
  Then we reconfigure the fs to RW.

- During reconfiguration, option/features check is skipped
  This means we will restart the v2 cache clearing, and convert back to
  v1 cache.
  This will trigger fs writes, and since the original fs has "rescue=all"
  option, it skips the csum tree read.

  And eventually causing NULL pointer dereference in super block
  writeback.

[FIX]
For reconfiguration caused by different subvolume RO/RW flags, ensure we
always run btrfs_check_options() to ensure we have proper hard RO
requirements met.

In fact the function btrfs_check_options() doesn't really do many
complex checks, but hard RO requirement and some feature dependency
checks, thus there is no special reason not to do the check for mount
reconfiguration.

Reported-by: syzbot+56360f93efa90ff15870@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/0000000000008c5d090621cb2770@google.com/
Fixes: f044b31 ("btrfs: handle the ro->rw transition for mounting different subvolumes")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
When creating a trace_probe we would set nr_args prior to truncating the
arguments to MAX_TRACE_ARGS. However, we would only initialize arguments
up to the limit.

This caused invalid memory access when attempting to set up probes with
more than 128 fetchargs.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 UID: 0 PID: 1769 Comm: cat Not tainted 6.11.0-rc7+ #8
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
  RIP: 0010:__set_print_fmt+0x134/0x330

Resolve the issue by applying the MAX_TRACE_ARGS limit earlier. Return
an error when there are too many arguments instead of silently
truncating.

Link: https://lore.kernel.org/all/20240930202656.292869-1-mikel@mikelr.com/

Fixes: 035ba76 ("tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init")
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
…ing to satisfy some BPF verifiers

In a RHEL8 kernel (4.18.0-513.11.1.el8_9.x86_64), that, as enterprise
kernels go, have backports from modern kernels, the verifier complains
about lack of bounds check for the index into the array of syscall
arguments, on a BPF bytecode generated by clang 17, with:

  ; } else if (size < 0 && size >= -6) { /* buffer */
  116: (b7) r1 = -6
  117: (2d) if r1 > r6 goto pc-30
   R0=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=inv-6 R2=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3=inv(id=0) R5=inv40 R6=inv(id=0,umin_value=18446744073709551610,var_off=(0xffffffff00000000; 0xffffffff)) R7=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8=invP6 R9=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16=map_value fp-24=map_value fp-32=inv40 fp-40=ctx fp-48=map_value fp-56=inv1 fp-64=map_value fp-72=map_value fp-80=map_value
  ; index = -(size + 1);
  118: (a7) r6 ^= -1
  119: (67) r6 <<= 32
  120: (77) r6 >>= 32
  ; aug_size = args->args[index];
  121: (67) r6 <<= 3
  122: (79) r1 = *(u64 *)(r10 -24)
  123: (0f) r1 += r6
  last_idx 123 first_idx 116
  regs=40 stack=0 before 122: (79) r1 = *(u64 *)(r10 -24)
  regs=40 stack=0 before 121: (67) r6 <<= 3
  regs=40 stack=0 before 120: (77) r6 >>= 32
  regs=40 stack=0 before 119: (67) r6 <<= 32
  regs=40 stack=0 before 118: (a7) r6 ^= -1
  regs=40 stack=0 before 117: (2d) if r1 > r6 goto pc-30
  regs=42 stack=0 before 116: (b7) r1 = -6
   R0_w=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=inv1 R2_w=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3_w=inv(id=0) R5_w=inv40 R6_rw=invP(id=0,smin_value=-2147483648,smax_value=0) R7_w=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8_w=invP6 R9_w=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16_w=map_value fp-24_r=map_value fp-32_w=inv40 fp-40=ctx fp-48=map_value fp-56_w=inv1 fp-64_w=map_value fp-72=map_value fp-80=map_value
  parent didn't have regs=40 stack=0 marks
  last_idx 110 first_idx 98
  regs=40 stack=0 before 110: (6d) if r1 s> r6 goto pc+5
  regs=42 stack=0 before 109: (b7) r1 = 1
  regs=40 stack=0 before 108: (65) if r6 s> 0x1000 goto pc+7
  regs=40 stack=0 before 98: (55) if r6 != 0x1 goto pc+9
   R0_w=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=invP12 R2_w=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3_rw=inv(id=0) R5_w=inv24 R6_rw=invP(id=0,smin_value=-2147483648,smax_value=2147483647) R7_w=map_value(id=0,off=40,ks=4,vs=8272,imm=0) R8_rw=invP4 R9_w=map_value(id=0,off=12,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16_rw=map_value fp-24_r=map_value fp-32_rw=invP24 fp-40_r=ctx fp-48_r=map_value fp-56_w=invP1 fp-64_rw=map_value fp-72_r=map_value fp-80_r=map_value
  parent already had regs=40 stack=0 marks
  124: (79) r6 = *(u64 *)(r1 +16)
   R0=map_value(id=0,off=0,ks=4,vs=24688,imm=0) R1_w=map_value(id=0,off=0,ks=4,vs=8272,umax_value=34359738360,var_off=(0x0; 0x7fffffff8),s32_max_value=2147483640,u32_max_value=-8) R2=map_value(id=0,off=16,ks=4,vs=8272,imm=0) R3=inv(id=0) R5=inv40 R6_w=invP(id=0,umax_value=34359738360,var_off=(0x0; 0x7fffffff8),s32_max_value=2147483640,u32_max_value=-8) R7=map_value(id=0,off=56,ks=4,vs=8272,imm=0) R8=invP6 R9=map_value(id=0,off=20,ks=4,vs=24,imm=0) R10=fp0 fp-8=mmmmmmmm fp-16=map_value fp-24=map_value fp-32=inv40 fp-40=ctx fp-48=map_value fp-56=inv1 fp-64=map_value fp-72=map_value fp-80=map_value
  R1 unbounded memory access, make sure to bounds check any such access
  processed 466 insns (limit 1000000) max_states_per_insn 2 total_states 20 peak_states 20 mark_read 3

If we add this line, as used in other BPF programs, to cap that index:

   index &= 7;

The generated BPF program is considered safe by that version of the BPF
verifier, allowing perf to collect the syscall args in one more kernel
using the BPF based pointer contents collector.

With the above one-liner it works with that kernel:

  [root@dell-per740-01 ~]# uname -a
  Linux dell-per740-01.khw.eng.rdu2.dc.redhat.com 4.18.0-513.11.1.el8_9.x86_64 #1 SMP Thu Dec 7 03:06:13 EST 2023 x86_64 x86_64 x86_64 GNU/Linux
  [root@dell-per740-01 ~]# ~acme/bin/perf trace -e *sleep* sleep 1.234567890
       0.000 (1234.704 ms): sleep/3863610 nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 234567890 })                  = 0
  [root@dell-per740-01 ~]#

As well as with the one in Fedora 40:

  root@number:~# uname -a
  Linux number 6.11.3-200.fc40.x86_64 #1 SMP PREEMPT_DYNAMIC Thu Oct 10 22:31:19 UTC 2024 x86_64 GNU/Linux
  root@number:~# perf trace -e *sleep* sleep 1.234567890
       0.000 (1234.722 ms): sleep/14873 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 234567890 }, rmtp: 0x7ffe87311a40) = 0
  root@number:~#

Song Liu reported that this one-liner was being optimized out by clang
18, so I suggested and he tested that adding a compiler barrier before
it made clang v18 to keep it and the verifier in the kernel in Song's
case (Meta's 5.12 based kernel) also was happy with the resulting
bytecode.

I'll investigate using virtme-ng[1] to have all the perf BPF based
functionality thoroughly tested over multiple kernels and clang
versions.

[1] https://kernel-recipes.org/en/2024/virtme-ng/

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrea Righi <andrea.righi@linux.dev>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/lkml/Zw7JgJc0LOwSpuvx@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
The purpose of btrfs_bbio_propagate_error() shall be propagating an error
of split bio to its original btrfs_bio, and tell the error to the upper
layer. However, it's not working well on some cases.

* Case 1. Immediate (or quick) end_bio with an error

When btrfs sends btrfs_bio to mirrored devices, btrfs calls
btrfs_bio_end_io() when all the mirroring bios are completed. If that
btrfs_bio was split, it is from btrfs_clone_bioset and its end_io function
is btrfs_orig_write_end_io. For this case, btrfs_bbio_propagate_error()
accesses the orig_bbio's bio context to increase the error count.

That works well in most cases. However, if the end_io is called enough
fast, orig_bbio's (remaining part after split) bio context may not be
properly set at that time. Since the bio context is set when the orig_bbio
(the last btrfs_bio) is sent to devices, that might be too late for earlier
split btrfs_bio's completion.  That will result in NULL pointer
dereference.

That bug is easily reproducible by running btrfs/146 on zoned devices [1]
and it shows the following trace.

[1] You need raid-stripe-tree feature as it create "-d raid0 -m raid1" FS.

  BUG: kernel NULL pointer dereference, address: 0000000000000020
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] PREEMPT SMP PTI
  CPU: 1 UID: 0 PID: 13 Comm: kworker/u32:1 Not tainted 6.11.0-rc7-BTRFS-ZNS+ torvalds#474
  Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  Workqueue: writeback wb_workfn (flush-btrfs-5)
  RIP: 0010:btrfs_bio_end_io+0xae/0xc0 [btrfs]
  BTRFS error (device dm-0): bdev /dev/mapper/error-test errs: wr 2, rd 0, flush 0, corrupt 0, gen 0
  RSP: 0018:ffffc9000006f248 EFLAGS: 00010246
  RAX: 0000000000000000 RBX: ffff888005a7f080 RCX: ffffc9000006f1dc
  RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff888005a7f080
  RBP: ffff888011dfc540 R08: 0000000000000000 R09: 0000000000000001
  R10: ffffffff82e508e0 R11: 0000000000000005 R12: ffff88800ddfbe58
  R13: ffff888005a7f080 R14: ffff888005a7f158 R15: ffff888005a7f158
  FS:  0000000000000000(0000) GS:ffff88803ea80000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000020 CR3: 0000000002e22006 CR4: 0000000000370ef0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   ? __die_body.cold+0x19/0x26
   ? page_fault_oops+0x13e/0x2b0
   ? _printk+0x58/0x73
   ? do_user_addr_fault+0x5f/0x750
   ? exc_page_fault+0x76/0x240
   ? asm_exc_page_fault+0x22/0x30
   ? btrfs_bio_end_io+0xae/0xc0 [btrfs]
   ? btrfs_log_dev_io_error+0x7f/0x90 [btrfs]
   btrfs_orig_write_end_io+0x51/0x90 [btrfs]
   dm_submit_bio+0x5c2/0xa50 [dm_mod]
   ? find_held_lock+0x2b/0x80
   ? blk_try_enter_queue+0x90/0x1e0
   __submit_bio+0xe0/0x130
   ? ktime_get+0x10a/0x160
   ? lockdep_hardirqs_on+0x74/0x100
   submit_bio_noacct_nocheck+0x199/0x410
   btrfs_submit_bio+0x7d/0x150 [btrfs]
   btrfs_submit_chunk+0x1a1/0x6d0 [btrfs]
   ? lockdep_hardirqs_on+0x74/0x100
   ? __folio_start_writeback+0x10/0x2c0
   btrfs_submit_bbio+0x1c/0x40 [btrfs]
   submit_one_bio+0x44/0x60 [btrfs]
   submit_extent_folio+0x13f/0x330 [btrfs]
   ? btrfs_set_range_writeback+0xa3/0xd0 [btrfs]
   extent_writepage_io+0x18b/0x360 [btrfs]
   extent_write_locked_range+0x17c/0x340 [btrfs]
   ? __pfx_end_bbio_data_write+0x10/0x10 [btrfs]
   run_delalloc_cow+0x71/0xd0 [btrfs]
   btrfs_run_delalloc_range+0x176/0x500 [btrfs]
   ? find_lock_delalloc_range+0x119/0x260 [btrfs]
   writepage_delalloc+0x2ab/0x480 [btrfs]
   extent_write_cache_pages+0x236/0x7d0 [btrfs]
   btrfs_writepages+0x72/0x130 [btrfs]
   do_writepages+0xd4/0x240
   ? find_held_lock+0x2b/0x80
   ? wbc_attach_and_unlock_inode+0x12c/0x290
   ? wbc_attach_and_unlock_inode+0x12c/0x290
   __writeback_single_inode+0x5c/0x4c0
   ? do_raw_spin_unlock+0x49/0xb0
   writeback_sb_inodes+0x22c/0x560
   __writeback_inodes_wb+0x4c/0xe0
   wb_writeback+0x1d6/0x3f0
   wb_workfn+0x334/0x520
   process_one_work+0x1ee/0x570
   ? lock_is_held_type+0xc6/0x130
   worker_thread+0x1d1/0x3b0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0xee/0x120
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x30/0x50
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>
  Modules linked in: dm_mod btrfs blake2b_generic xor raid6_pq rapl
  CR2: 0000000000000020

* Case 2. Earlier completion of orig_bbio for mirrored btrfs_bios

btrfs_bbio_propagate_error() assumes the end_io function for orig_bbio is
called last among split bios. In that case, btrfs_orig_write_end_io() sets
the bio->bi_status to BLK_STS_IOERR by seeing the bioc->error [2].
Otherwise, the increased orig_bio's bioc->error is not checked by anyone
and return BLK_STS_OK to the upper layer.

[2] Actually, this is not true. Because we only increases orig_bioc->errors
by max_errors, the condition "atomic_read(&bioc->error) > bioc->max_errors"
is still not met if only one split btrfs_bio fails.

* Case 3. Later completion of orig_bbio for un-mirrored btrfs_bios

In contrast to the above case, btrfs_bbio_propagate_error() is not working
well if un-mirrored orig_bbio is completed last. It sets
orig_bbio->bio.bi_status to the btrfs_bio's error. But, that is easily
over-written by orig_bbio's completion status. If the status is BLK_STS_OK,
the upper layer would not know the failure.

* Solution

Considering the above cases, we can only save the error status in the
orig_bbio (remaining part after split) itself as it is always
available. Also, the saved error status should be propagated when all the
split btrfs_bios are finished (i.e, bbio->pending_ios == 0).

This commit introduces "status" to btrfs_bbio and saves the first error of
split bios to original btrfs_bio's "status" variable. When all the split
bios are finished, the saved status is loaded into original btrfs_bio's
status.

With this commit, btrfs/146 on zoned devices does not hit the NULL pointer
dereference anymore.

Fixes: 852eee6 ("btrfs: allow btrfs_submit_bio to split bios")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Running rcutorture scenario TREE05, the below warning is triggered.

[   32.604594] WARNING: suspicious RCU usage
[   32.605928] 6.11.0-rc5-00040-g4ba4f1afb6a9 #55238 Not tainted
[   32.607812] -----------------------------
[   32.609140] kernel/events/core.c:13946 RCU-list traversed in non-reader section!!
[   32.611595] other info that might help us debug this:
[   32.614247] rcu_scheduler_active = 2, debug_locks = 1
[   32.616392] 3 locks held by cpuhp/4/35:
[   32.617687]  #0: ffffffffb666a650 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x4e/0x200
[   32.620563]  #1: ffffffffb666cd20 (cpuhp_state-down){+.+.}-{0:0}, at: cpuhp_thread_fun+0x4e/0x200
[   32.623412]  #2: ffffffffb677c288 (pmus_lock){+.+.}-{3:3}, at: perf_event_exit_cpu_context+0x32/0x2f0

In perf_event_clear_cpumask(), uses list_for_each_entry_rcu() without an
obvious RCU read-side critical section.

Either pmus_srcu or pmus_lock is good enough to protect the pmus list.
In the current context, pmus_lock is already held. The
list_for_each_entry_rcu() is not required.

Fixes: 4ba4f1a ("perf: Generic hotplug support for a PMU with a scope")
Closes: https://lore.kernel.org/lkml/2b66dff8-b827-494b-b151-1ad8d56f13e6@paulmck-laptop/
Closes: https://lore.kernel.org/oe-lkp/202409131559.545634cc-oliver.sang@intel.com
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: "Paul E. McKenney" <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20240913162340.2142976-1-kan.liang@linux.intel.com
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Add check for the return value of spi_get_csgpiod() to avoid passing a NULL
pointer to gpiod_direction_output(), preventing a crash when GPIO chip
select is not used.

Fix below crash:
[    4.251960] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[    4.260762] Mem abort info:
[    4.263556]   ESR = 0x0000000096000004
[    4.267308]   EC = 0x25: DABT (current EL), IL = 32 bits
[    4.272624]   SET = 0, FnV = 0
[    4.275681]   EA = 0, S1PTW = 0
[    4.278822]   FSC = 0x04: level 0 translation fault
[    4.283704] Data abort info:
[    4.286583]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[    4.292074]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[    4.297130]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[    4.302445] [0000000000000000] user address but active_mm is swapper
[    4.308805] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
[    4.315072] Modules linked in:
[    4.318124] CPU: 2 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc4-next-20241023-00008-ga20ec42c5fc1 torvalds#359
[    4.328130] Hardware name: LS1046A QDS Board (DT)
[    4.332832] pstate: 40000005 (nZcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[    4.339794] pc : gpiod_direction_output+0x34/0x5c
[    4.344505] lr : gpiod_direction_output+0x18/0x5c
[    4.349208] sp : ffff80008003b8f0
[    4.352517] x29: ffff80008003b8f0 x28: 0000000000000000 x27: ffffc96bcc7e9068
[    4.359659] x26: ffffc96bcc6e00b0 x25: ffffc96bcc598398 x24: ffff447400132810
[    4.366800] x23: 0000000000000000 x22: 0000000011e1a300 x21: 0000000000020002
[    4.373940] x20: 0000000000000000 x19: 0000000000000000 x18: ffffffffffffffff
[    4.381081] x17: ffff44740016e600 x16: 0000000500000003 x15: 0000000000000007
[    4.388221] x14: 0000000000989680 x13: 0000000000020000 x12: 000000000000001e
[    4.395362] x11: 0044b82fa09b5a53 x10: 0000000000000019 x9 : 0000000000000008
[    4.402502] x8 : 0000000000000002 x7 : 0000000000000007 x6 : 0000000000000000
[    4.409641] x5 : 0000000000000200 x4 : 0000000002000000 x3 : 0000000000000000
[    4.416781] x2 : 0000000000022202 x1 : 0000000000000000 x0 : 0000000000000000
[    4.423921] Call trace:
[    4.426362]  gpiod_direction_output+0x34/0x5c (P)
[    4.431067]  gpiod_direction_output+0x18/0x5c (L)
[    4.435771]  dspi_setup+0x220/0x334

Fixes: 9e264f3 ("spi: Replace all spi->chip_select and spi->cs_gpiod references with function call")
Cc: stable@vger.kernel.org
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20241023203032.1388491-1-Frank.Li@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
… non-PCI device

The function cxl_endpoint_gather_bandwidth() invokes
pci_bus_read/write_XXX(), however, not all CXL devices are presently
implemented via PCI. It is recognized that the cxl_test has realized a CXL
device using a platform device.

Calling pci_bus_read/write_XXX() in cxl_test will cause kernel panic:
 platform cxl_host_bridge.3: host supports CXL (restricted)
 Oops: general protection fault, probably for non-canonical address 0x3ef17856fcae4fbd: 0000 [#1] PREEMPT SMP PTI
 Call Trace:
  <TASK>
  ? __die_body.cold+0x19/0x27
  ? die_addr+0x38/0x60
  ? exc_general_protection+0x1f5/0x4b0
  ? asm_exc_general_protection+0x22/0x30
  ? pci_bus_read_config_word+0x1c/0x60
  pcie_capability_read_word+0x93/0xb0
  pcie_link_speed_mbps+0x18/0x50
  cxl_pci_get_bandwidth+0x18/0x60 [cxl_core]
  cxl_endpoint_gather_bandwidth.constprop.0+0xf4/0x230 [cxl_core]
  ? xas_store+0x54/0x660
  ? preempt_count_add+0x69/0xa0
  ? _raw_spin_lock+0x13/0x40
  ? __kmalloc_cache_noprof+0xe7/0x270
  cxl_region_shared_upstream_bandwidth_update+0x9c/0x790 [cxl_core]
  cxl_region_attach+0x520/0x7e0 [cxl_core]
  store_targetN+0xf2/0x120 [cxl_core]
  kernfs_fop_write_iter+0x13a/0x1f0
  vfs_write+0x23b/0x410
  ksys_write+0x53/0xd0
  do_syscall_64+0x62/0x180
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

And Ying also reported a KASAN error with similar calltrace.

Reported-by: Huang, Ying <ying.huang@intel.com>
Closes: http://lore.kernel.org/87y12w9vp5.fsf@yhuang6-desk2.ccr.corp.intel.com
Fixes: a5ab0de ("cxl: Calculate region bandwidth of targets with shared upstream link")
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Huang, Ying <ying.huang@intel.com>
Link: https://patch.msgid.link/20241022030054.258942-1-lizhijian@fujitsu.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
In support of investigating an initialization failure report [1],
cxl_test was updated to register mock memory-devices after the mock
root-port/bus device had been registered. That led to cxl_test crashing
with a use-after-free bug with the following signature:

    cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem0:decoder7.0 @ 0 next: cxl_switch_uport.0 nr_eps: 1 nr_targets: 1
    cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem4:decoder14.0 @ 1 next: cxl_switch_uport.0 nr_eps: 2 nr_targets: 1
    cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[0] = cxl_switch_dport.0 for mem0:decoder7.0 @ 0
1)  cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[1] = cxl_switch_dport.4 for mem4:decoder14.0 @ 1
    [..]
    cxld_unregister: cxl decoder14.0:
    cxl_region_decode_reset: cxl_region region3:
    mock_decoder_reset: cxl_port port3: decoder3.0 reset
2)  mock_decoder_reset: cxl_port port3: decoder3.0: out of order reset, expected decoder3.1
    cxl_endpoint_decoder_release: cxl decoder14.0:
    [..]
    cxld_unregister: cxl decoder7.0:
3)  cxl_region_decode_reset: cxl_region region3:
    Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP PTI
    [..]
    RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core]
    [..]
    Call Trace:
     <TASK>
     cxl_region_decode_reset+0x69/0x190 [cxl_core]
     cxl_region_detach+0xe8/0x210 [cxl_core]
     cxl_decoder_kill_region+0x27/0x40 [cxl_core]
     cxld_unregister+0x5d/0x60 [cxl_core]

At 1) a region has been established with 2 endpoint decoders (7.0 and
14.0). Those endpoints share a common switch-decoder in the topology
(3.0). At teardown, 2), decoder14.0 is the first to be removed and hits
the "out of order reset case" in the switch decoder. The effect though
is that region3 cleanup is aborted leaving it in-tact and
referencing decoder14.0. At 3) the second attempt to teardown region3
trips over the stale decoder14.0 object which has long since been
deleted.

The fix here is to recognize that the CXL specification places no
mandate on in-order shutdown of switch-decoders, the driver enforces
in-order allocation, and hardware enforces in-order commit. So, rather
than fail and leave objects dangling, always remove them.

In support of making cxl_region_decode_reset() always succeed,
cxl_region_invalidate_memregion() failures are turned into warnings.
Crashing the kernel is ok there since system integrity is at risk if
caches cannot be managed around physical address mutation events like
CXL region destruction.

A new device_for_each_child_reverse_from() is added to cleanup
port->commit_end after all dependent decoders have been disabled. In
other words if decoders are allocated 0->1->2 and disabled 1->2->0 then
port->commit_end only decrements from 2 after 2 has been disabled, and
it decrements all the way to zero since 1 was disabled previously.

Link: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net [1]
Cc: stable@vger.kernel.org
Fixes: 176baef ("cxl/hdm: Commit decoder state to hardware")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Zijun Hu <quic_zijuhu@quicinc.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://patch.msgid.link/172964782781.81806.17902885593105284330.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Under memory pressure it's possible for GFP_ATOMIC order-0 allocations to
fail even though free pages are available in the highatomic reserves. 
GFP_ATOMIC allocations cannot trigger unreserve_highatomic_pageblock()
since it's only run from reclaim.

Given that such allocations will pass the watermarks in
__zone_watermark_unusable_free(), it makes sense to fallback to highatomic
reserves the same way that ALLOC_OOM can.

This fixes order-0 page allocation failures observed on Cloudflare's fleet
when handling network packets:

  kswapd1: page allocation failure: order:0, mode:0x820(GFP_ATOMIC),
  nodemask=(null),cpuset=/,mems_allowed=0-7
  CPU: 10 PID: 696 Comm: kswapd1 Kdump: loaded Tainted: G           O 6.6.43-CUSTOM #1
  Hardware name: MACHINE
  Call Trace:
   <IRQ>
   dump_stack_lvl+0x3c/0x50
   warn_alloc+0x13a/0x1c0
   __alloc_pages_slowpath.constprop.0+0xc9d/0xd10
   __alloc_pages+0x327/0x340
   __napi_alloc_skb+0x16d/0x1f0
   bnxt_rx_page_skb+0x96/0x1b0 [bnxt_en]
   bnxt_rx_pkt+0x201/0x15e0 [bnxt_en]
   __bnxt_poll_work+0x156/0x2b0 [bnxt_en]
   bnxt_poll+0xd9/0x1c0 [bnxt_en]
   __napi_poll+0x2b/0x1b0
   bpf_trampoline_6442524138+0x7d/0x1000
   __napi_poll+0x5/0x1b0
   net_rx_action+0x342/0x740
   handle_softirqs+0xcf/0x2b0
   irq_exit_rcu+0x6c/0x90
   sysvec_apic_timer_interrupt+0x72/0x90
   </IRQ>

[mfleming@cloudflare.com: update comment]
  Link: https://lkml.kernel.org/r/20241015125158.3597702-1-matt@readmodwrite.com
Link: https://lkml.kernel.org/r/20241011120737.3300370-1-matt@readmodwrite.com
Link: https://lore.kernel.org/all/CAGis_TWzSu=P7QJmjD58WWiu3zjMTVKSzdOwWE8ORaGytzWJwQ@mail.gmail.com/
Fixes: 1d91df8 ("mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore} APIs")
Signed-off-by: Matt Fleming <mfleming@cloudflare.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
walk_system_ram_res_rev() erroneously discards resource flags when passing
the information to the callback.

This causes systems with IORESOURCE_SYSRAM_DRIVER_MANAGED memory to have
these resources selected during kexec to store kexec buffers if that
memory happens to be at placed above normal system ram.

This leads to undefined behavior after reboot.  If the kexec buffer is
never touched, nothing happens.  If the kexec buffer is touched, it could
lead to a crash (like below) or undefined behavior.

Tested on a system with CXL memory expanders with driver managed memory,
TPM enabled, and CONFIG_IMA_KEXEC=y.  Adding printk's showed the flags
were being discarded and as a result the check for
IORESOURCE_SYSRAM_DRIVER_MANAGED passes.

find_next_iomem_res: name(System RAM (kmem))
		     start(10000000000)
		     end(1034fffffff)
		     flags(83000200)

locate_mem_hole_top_down: start(10000000000) end(1034fffffff) flags(0)

[.] BUG: unable to handle page fault for address: ffff89834ffff000
[.] #PF: supervisor read access in kernel mode
[.] #PF: error_code(0x0000) - not-present page
[.] PGD c04c8bf067 P4D c04c8bf067 PUD c04c8be067 PMD 0
[.] Oops: 0000 [#1] SMP
[.] RIP: 0010:ima_restore_measurement_list+0x95/0x4b0
[.] RSP: 0018:ffffc900000d3a80 EFLAGS: 00010286
[.] RAX: 0000000000001000 RBX: 0000000000000000 RCX: ffff89834ffff000
[.] RDX: 0000000000000018 RSI: ffff89834ffff000 RDI: ffff89834ffff018
[.] RBP: ffffc900000d3ba0 R08: 0000000000000020 R09: ffff888132b8a900
[.] R10: 4000000000000000 R11: 000000003a616d69 R12: 0000000000000000
[.] R13: ffffffff8404ac28 R14: 0000000000000000 R15: ffff89834ffff000
[.] FS:  0000000000000000(0000) GS:ffff893d44640000(0000) knlGS:0000000000000000
[.] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[.] ata5: SATA link down (SStatus 0 SControl 300)
[.] CR2: ffff89834ffff000 CR3: 000001034d00f001 CR4: 0000000000770ef0
[.] PKRU: 55555554
[.] Call Trace:
[.]  <TASK>
[.]  ? __die+0x78/0xc0
[.]  ? page_fault_oops+0x2a8/0x3a0
[.]  ? exc_page_fault+0x84/0x130
[.]  ? asm_exc_page_fault+0x22/0x30
[.]  ? ima_restore_measurement_list+0x95/0x4b0
[.]  ? template_desc_init_fields+0x317/0x410
[.]  ? crypto_alloc_tfm_node+0x9c/0xc0
[.]  ? init_ima_lsm+0x30/0x30
[.]  ima_load_kexec_buffer+0x72/0xa0
[.]  ima_init+0x44/0xa0
[.]  __initstub__kmod_ima__373_1201_init_ima7+0x1e/0xb0
[.]  ? init_ima_lsm+0x30/0x30
[.]  do_one_initcall+0xad/0x200
[.]  ? idr_alloc_cyclic+0xaa/0x110
[.]  ? new_slab+0x12c/0x420
[.]  ? new_slab+0x12c/0x420
[.]  ? number+0x12a/0x430
[.]  ? sysvec_apic_timer_interrupt+0xa/0x80
[.]  ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[.]  ? parse_args+0xd4/0x380
[.]  ? parse_args+0x14b/0x380
[.]  kernel_init_freeable+0x1c1/0x2b0
[.]  ? rest_init+0xb0/0xb0
[.]  kernel_init+0x16/0x1a0
[.]  ret_from_fork+0x2f/0x40
[.]  ? rest_init+0xb0/0xb0
[.]  ret_from_fork_asm+0x11/0x20
[.]  </TASK>

Link: https://lore.kernel.org/all/20231114091658.228030-1-bhe@redhat.com/
Link: https://lkml.kernel.org/r/20241017190347.5578-1-gourry@gourry.net
Fixes: 7acf164 ("resource: add walk_system_ram_res_rev()")
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
The following BUG was triggered:

=============================
[ BUG: Invalid wait context ]
6.12.0-rc2-XXX torvalds#406 Not tainted
-----------------------------
kworker/1:1/62 is trying to lock:
ffffff8801593030 (&cpc_ptr->rmw_lock){+.+.}-{3:3}, at: cpc_write+0xcc/0x370
other info that might help us debug this:
context-{5:5}
2 locks held by kworker/1:1/62:
  #0: ffffff897ef5ec98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x50
  #1: ffffff880154e238 (&sg_policy->update_lock){....}-{2:2}, at: sugov_update_shared+0x3c/0x280
stack backtrace:
CPU: 1 UID: 0 PID: 62 Comm: kworker/1:1 Not tainted 6.12.0-rc2-g9654bd3e8806 torvalds#406
Workqueue:  0x0 (events)
Call trace:
  dump_backtrace+0xa4/0x130
  show_stack+0x20/0x38
  dump_stack_lvl+0x90/0xd0
  dump_stack+0x18/0x28
  __lock_acquire+0x480/0x1ad8
  lock_acquire+0x114/0x310
  _raw_spin_lock+0x50/0x70
  cpc_write+0xcc/0x370
  cppc_set_perf+0xa0/0x3a8
  cppc_cpufreq_fast_switch+0x40/0xc0
  cpufreq_driver_fast_switch+0x4c/0x218
  sugov_update_shared+0x234/0x280
  update_load_avg+0x6ec/0x7b8
  dequeue_entities+0x108/0x830
  dequeue_task_fair+0x58/0x408
  __schedule+0x4f0/0x1070
  schedule+0x54/0x130
  worker_thread+0xc0/0x2e8
  kthread+0x130/0x148
  ret_from_fork+0x10/0x20

sugov_update_shared() locks a raw_spinlock while cpc_write() locks a
spinlock.

To have a correct wait-type order, update rmw_lock to a raw spinlock and
ensure that interrupts will be disabled on the CPU holding it.

Fixes: 60949b7 ("ACPI: CPPC: Fix MASK_VAL() usage")
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Link: https://patch.msgid.link/20241028125657.1271512-1-pierre.gondois@arm.com
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
I got a syzbot report without a repro [1] crashing in nf_send_reset6()

I think the issue is that dev->hard_header_len is zero, and we attempt
later to push an Ethernet header.

Use LL_MAX_HEADER, as other functions in net/ipv6/netfilter/nf_reject_ipv6.c.

[1]

skbuff: skb_under_panic: text:ffffffff89b1d008 len:74 put:14 head:ffff88803123aa00 data:ffff88803123a9f2 tail:0x3c end:0x140 dev:syz_tun
 kernel BUG at net/core/skbuff.c:206 !
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 7373 Comm: syz.1.568 Not tainted 6.12.0-rc2-syzkaller-00631-g6d858708d465 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
 RIP: 0010:skb_panic net/core/skbuff.c:206 [inline]
 RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216
Code: 0d 8d 48 c7 c6 60 a6 29 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 ba 30 38 02 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc900045269b0 EFLAGS: 00010282
RAX: 0000000000000088 RBX: dffffc0000000000 RCX: cd66dacdc5d8e800
RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000
RBP: ffff88802d39a3d0 R08: ffffffff8174afec R09: 1ffff920008a4ccc
R10: dffffc0000000000 R11: fffff520008a4ccd R12: 0000000000000140
R13: ffff88803123aa00 R14: ffff88803123a9f2 R15: 000000000000003c
FS:  00007fdbee5ff6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005d322000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
  skb_push+0xe5/0x100 net/core/skbuff.c:2636
  eth_header+0x38/0x1f0 net/ethernet/eth.c:83
  dev_hard_header include/linux/netdevice.h:3208 [inline]
  nf_send_reset6+0xce6/0x1270 net/ipv6/netfilter/nf_reject_ipv6.c:358
  nft_reject_inet_eval+0x3b9/0x690 net/netfilter/nft_reject_inet.c:48
  expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
  nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288
  nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626
  nf_hook include/linux/netfilter.h:269 [inline]
  NF_HOOK include/linux/netfilter.h:312 [inline]
  br_nf_pre_routing_ipv6+0x63e/0x770 net/bridge/br_netfilter_ipv6.c:184
  nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
  nf_hook_bridge_pre net/bridge/br_input.c:277 [inline]
  br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424
  __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5562
  __netif_receive_skb_one_core net/core/dev.c:5666 [inline]
  __netif_receive_skb+0x12f/0x650 net/core/dev.c:5781
  netif_receive_skb_internal net/core/dev.c:5867 [inline]
  netif_receive_skb+0x1e8/0x890 net/core/dev.c:5926
  tun_rx_batched+0x1b7/0x8f0 drivers/net/tun.c:1550
  tun_get_user+0x3056/0x47e0 drivers/net/tun.c:2007
  tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2053
  new_sync_write fs/read_write.c:590 [inline]
  vfs_write+0xa6d/0xc90 fs/read_write.c:683
  ksys_write+0x183/0x2b0 fs/read_write.c:736
  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdbeeb7d1ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 c9 8d 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 1c 8e 02 00 48
RSP: 002b:00007fdbee5ff000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fdbeed36058 RCX: 00007fdbeeb7d1ff
RDX: 000000000000008e RSI: 0000000020000040 RDI: 00000000000000c8
RBP: 00007fdbeebf12be R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000008e R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdbeed36058 R15: 00007ffc38de06e8
 </TASK>

Fixes: c8d7b98 ("netfilter: move nf_send_resetX() code to nf_reject_ipvX modules")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Hou Tao says:

====================
The patch set fixes several issues in bits iterator. Patch #1 fixes the
kmemleak problem of bits iterator. Patch #2~#3 fix the overflow problem
of nr_bits. Patch #4 fixes the potential stack corruption when bits
iterator is used on 32-bit host. Patch #5 adds more test cases for bits
iterator.

Please see the individual patches for more details. And comments are
always welcome.
---
v4:
 * patch #1: add ack from Yafang
 * patch #3: revert code-churn like changes:
   (1) compute nr_bytes and nr_bits before the check of nr_words.
   (2) use nr_bits == 64 to check for single u64, preventing build
       warning on 32-bit hosts.
 * patch #4: use "BITS_PER_LONG == 32" instead of "!defined(CONFIG_64BIT)"

v3: https://lore.kernel.org/bpf/20241025013233.804027-1-houtao@huaweicloud.com/T/#t
  * split the bits-iterator related patches from "Misc fixes for bpf"
    patch set
  * patch #1: use "!nr_bits || bits >= nr_bits" to stop the iteration
  * patch #2: add a new helper for the overflow problem
  * patch #3: decrease the limitation from 512 to 511 and check whether
    nr_bytes is too large for bpf memory allocator explicitly
  * patch #5: add two more test cases for bit iterator

v2: http://lore.kernel.org/bpf/d49fa2f4-f743-c763-7579-c3cab4dd88cb@huaweicloud.com
====================

Link: https://lore.kernel.org/r/20241030100516.3633640-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Petr Machata says:

====================
mlxsw: Fixes

In this patchset:

- Tx header should be pushed for each packet which is transmitted via
  Spectrum ASICs. Patch #1 adds a missing call to skb_cow_head() to make
  sure that there is both enough room to push the Tx header and that the
  SKB header is not cloned and can be modified.

- Commit b5b60bb ("mlxsw: pci: Use page pool for Rx buffers
  allocation") converted mlxsw to use page pool for Rx buffers allocation.
  Sync for CPU and for device should be done for Rx pages. In patches #2
  and #3, add the missing calls to sync pages for, respectively, CPU and
  the device.

- Patch #4 then fixes a bug to IPv6 GRE forwarding offload. Patch #5 adds
  a generic forwarding test that fails with mlxsw ports prior to the fix.
====================

Link: https://patch.msgid.link/cover.1729866134.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
When we compile and load lib/slub_kunit.c,it will cause a panic.

The root cause is that __kmalloc_cache_noprof was directly called instead
of kmem_cache_alloc,which resulted in no alloc_tag being allocated.This
caused current->alloc_tag to be null,leading to a null pointer dereference
in alloc_tag_ref_set.

Despite the fact that my colleague Pei Xiao will later fix the code in
slub_kunit.c,we still need fix null pointer check logic for ref and tag to
avoid panic caused by a null pointer dereference.

Here is the log for the panic:

[   74.779373][ T2158] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
[   74.780130][ T2158] Mem abort info:
[   74.780406][ T2158]   ESR = 0x0000000096000004
[   74.780756][ T2158]   EC = 0x25: DABT (current EL), IL = 32 bits
[   74.781225][ T2158]   SET = 0, FnV = 0
[   74.781529][ T2158]   EA = 0, S1PTW = 0
[   74.781836][ T2158]   FSC = 0x04: level 0 translation fault
[   74.782288][ T2158] Data abort info:
[   74.782577][ T2158]   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
[   74.783068][ T2158]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[   74.783533][ T2158]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   74.784010][ T2158] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000105f34000
[   74.784586][ T2158] [0000000000000020] pgd=0000000000000000, p4d=0000000000000000
[   74.785293][ T2158] Internal error: Oops: 0000000096000004 [#1] SMP
[   74.785805][ T2158] Modules linked in: slub_kunit kunit ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle 4
[   74.790661][ T2158] CPU: 0 UID: 0 PID: 2158 Comm: kunit_try_catch Kdump: loaded Tainted: G        W        N 6.12.0-rc3+ #2
[   74.791535][ T2158] Tainted: [W]=WARN, [N]=TEST
[   74.791889][ T2158] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[   74.792479][ T2158] pstate: 40400005 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   74.793101][ T2158] pc : alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.793607][ T2158] lr : alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.794095][ T2158] sp : ffff800084d33cd0
[   74.794418][ T2158] x29: ffff800084d33cd0 x28: 0000000000000000 x27: 0000000000000000
[   74.795095][ T2158] x26: 0000000000000000 x25: 0000000000000012 x24: ffff80007b30e314
[   74.795822][ T2158] x23: ffff000390ff6f10 x22: 0000000000000000 x21: 0000000000000088
[   74.796555][ T2158] x20: ffff000390285840 x19: fffffd7fc3ef7830 x18: ffffffffffffffff
[   74.797283][ T2158] x17: ffff8000800e63b4 x16: ffff80007b33afc4 x15: ffff800081654c00
[   74.798011][ T2158] x14: 0000000000000000 x13: 205d383531325420 x12: 5b5d383734363537
[   74.798744][ T2158] x11: ffff800084d337e0 x10: 000000000000005d x9 : 00000000ffffffd0
[   74.799476][ T2158] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008219d188 x6 : c0000000ffff7fff
[   74.800206][ T2158] x5 : ffff0003fdbc9208 x4 : ffff800081edd188 x3 : 0000000000000001
[   74.800932][ T2158] x2 : 0beaa6dee1ac5a00 x1 : 0beaa6dee1ac5a00 x0 : ffff80037c2cb000
[   74.801656][ T2158] Call trace:
[   74.801954][ T2158]  alloc_tagging_slab_alloc_hook+0x120/0x270
[   74.802494][ T2158]  __kmalloc_cache_noprof+0x148/0x33c
[   74.802976][ T2158]  test_kmalloc_redzone_access+0x4c/0x104 [slub_kunit]
[   74.803607][ T2158]  kunit_try_run_case+0x70/0x17c [kunit]
[   74.804124][ T2158]  kunit_generic_run_threadfn_adapter+0x2c/0x4c [kunit]
[   74.804768][ T2158]  kthread+0x10c/0x118
[   74.805141][ T2158]  ret_from_fork+0x10/0x20
[   74.805540][ T2158] Code: b9400a80 11000400 b9000a80 97ffd858 (f94012d3)
[   74.806176][ T2158] SMP: stopping secondary CPUs
[   74.808130][ T2158] Starting crashdump kernel...

Link: https://lkml.kernel.org/r/20241020070819.307944-1-hao.ge@linux.dev
Fixes: e0a955b ("mm/codetag: add pgalloc_tag_copy()")
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Yu Zhao <yuzhao@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Enqueue packets in dql after dma engine starts causes race condition.
Tx transfer starts once dma engine is started and may execute dql dequeue
in completion before it gets queued. It results in following kernel crash
while running iperf stress test:

kernel BUG at lib/dynamic_queue_limits.c:99!
<snip>
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
pc : dql_completed+0x238/0x248
lr : dql_completed+0x3c/0x248

Call trace:
  dql_completed+0x238/0x248
  axienet_dma_tx_cb+0xa0/0x170
  xilinx_dma_do_tasklet+0xdc/0x290
  tasklet_action_common+0xf8/0x11c
  tasklet_action+0x30/0x3c
  handle_softirqs+0xf8/0x230
<snip>

Start dmaengine after enqueue in dql fixes the crash.

Fixes: 6a91b84 ("net: axienet: Introduce dmaengine support")
Signed-off-by: Suraj Gupta <suraj.gupta2@amd.com>
Link: https://patch.msgid.link/20241030062533.2527042-2-suraj.gupta2@amd.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Recently, we got a customer report that CIFS triggers oops while
reconnecting to a server.  [0]

The workload runs on Kubernetes, and some pods mount CIFS servers
in non-root network namespaces.  The problem rarely happened, but
it was always while the pod was dying.

The root cause is wrong reference counting for network namespace.

CIFS uses kernel sockets, which do not hold refcnt of the netns that
the socket belongs to.  That means CIFS must ensure the socket is
always freed before its netns; otherwise, use-after-free happens.

The repro steps are roughly:

  1. mount CIFS in a non-root netns
  2. drop packets from the netns
  3. destroy the netns
  4. unmount CIFS

We can reproduce the issue quickly with the script [1] below and see
the splat [2] if CONFIG_NET_NS_REFCNT_TRACKER is enabled.

When the socket is TCP, it is hard to guarantee the netns lifetime
without holding refcnt due to async timers.

Let's hold netns refcnt for each socket as done for SMC in commit
9744d2b ("smc: Fix use-after-free in tcp_write_timer_handler().").

Note that we need to move put_net() from cifs_put_tcp_session() to
clean_demultiplex_info(); otherwise, __sock_create() still could touch a
freed netns while cifsd tries to reconnect from cifs_demultiplex_thread().

Also, maybe_get_net() cannot be put just before __sock_create() because
the code is not under RCU and there is a small chance that the same
address happened to be reallocated to another netns.

[0]:
CIFS: VFS: \\XXXXXXXXXXX has not responded in 15 seconds. Reconnecting...
CIFS: Serverclose failed 4 times, giving up
Unable to handle kernel paging request at virtual address 14de99e461f84a07
Mem abort info:
  ESR = 0x0000000096000004
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000004
  CM = 0, WnR = 0
[14de99e461f84a07] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] SMP
Modules linked in: cls_bpf sch_ingress nls_utf8 cifs cifs_arc4 cifs_md4 dns_resolver tcp_diag inet_diag veth xt_state xt_connmark nf_conntrack_netlink xt_nat xt_statistic xt_MASQUERADE xt_mark xt_addrtype ipt_REJECT nf_reject_ipv4 nft_chain_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment nft_compat nf_tables nfnetlink overlay nls_ascii nls_cp437 sunrpc vfat fat aes_ce_blk aes_ce_cipher ghash_ce sm4_ce_cipher sm4 sm3_ce sm3 sha3_ce sha512_ce sha512_arm64 sha1_ce ena button sch_fq_codel loop fuse configfs dmi_sysfs sha2_ce sha256_arm64 dm_mirror dm_region_hash dm_log dm_mod dax efivarfs
CPU: 5 PID: 2690970 Comm: cifsd Not tainted 6.1.103-109.184.amzn2023.aarch64 #1
Hardware name: Amazon EC2 r7g.4xlarge/, BIOS 1.0 11/1/2018
pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : fib_rules_lookup+0x44/0x238
lr : __fib_lookup+0x64/0xbc
sp : ffff8000265db790
x29: ffff8000265db790 x28: 0000000000000000 x27: 000000000000bd01
x26: 0000000000000000 x25: ffff000b4baf8000 x24: ffff00047b5e4580
x23: ffff8000265db7e0 x22: 0000000000000000 x21: ffff00047b5e4500
x20: ffff0010e3f694f8 x19: 14de99e461f849f7 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000000 x12: 3f92800abd010002
x11: 0000000000000001 x10: ffff0010e3f69420 x9 : ffff800008a6f294
x8 : 0000000000000000 x7 : 0000000000000006 x6 : 0000000000000000
x5 : 0000000000000001 x4 : ffff001924354280 x3 : ffff8000265db7e0
x2 : 0000000000000000 x1 : ffff0010e3f694f8 x0 : ffff00047b5e4500
Call trace:
 fib_rules_lookup+0x44/0x238
 __fib_lookup+0x64/0xbc
 ip_route_output_key_hash_rcu+0x2c4/0x398
 ip_route_output_key_hash+0x60/0x8c
 tcp_v4_connect+0x290/0x488
 __inet_stream_connect+0x108/0x3d0
 inet_stream_connect+0x50/0x78
 kernel_connect+0x6c/0xac
 generic_ip_connect+0x10c/0x6c8 [cifs]
 __reconnect_target_unlocked+0xa0/0x214 [cifs]
 reconnect_dfs_server+0x144/0x460 [cifs]
 cifs_reconnect+0x88/0x148 [cifs]
 cifs_readv_from_socket+0x230/0x430 [cifs]
 cifs_read_from_socket+0x74/0xa8 [cifs]
 cifs_demultiplex_thread+0xf8/0x704 [cifs]
 kthread+0xd0/0xd4
Code: aa0003f8 f8480f13 eb18027f 540006c0 (b9401264)

[1]:
CIFS_CRED="/root/cred.cifs"
CIFS_USER="Administrator"
CIFS_PASS="Password"
CIFS_IP="X.X.X.X"
CIFS_PATH="//${CIFS_IP}/Users/Administrator/Desktop/CIFS_TEST"
CIFS_MNT="/mnt/smb"
DEV="enp0s3"

cat <<EOF > ${CIFS_CRED}
username=${CIFS_USER}
password=${CIFS_PASS}
domain=EXAMPLE.COM
EOF

unshare -n bash -c "
mkdir -p ${CIFS_MNT}
ip netns attach root 1
ip link add eth0 type veth peer veth0 netns root
ip link set eth0 up
ip -n root link set veth0 up
ip addr add 192.168.0.2/24 dev eth0
ip -n root addr add 192.168.0.1/24 dev veth0
ip route add default via 192.168.0.1 dev eth0
ip netns exec root sysctl net.ipv4.ip_forward=1
ip netns exec root iptables -t nat -A POSTROUTING -s 192.168.0.2 -o ${DEV} -j MASQUERADE
mount -t cifs ${CIFS_PATH} ${CIFS_MNT} -o vers=3.0,sec=ntlmssp,credentials=${CIFS_CRED},rsize=65536,wsize=65536,cache=none,echo_interval=1
touch ${CIFS_MNT}/a.txt
ip netns exec root iptables -t nat -D POSTROUTING -s 192.168.0.2 -o ${DEV} -j MASQUERADE
"

umount ${CIFS_MNT}

[2]:
ref_tracker: net notrefcnt@000000004bbc008d has 1/1 users at
     sk_alloc (./include/net/net_namespace.h:339 net/core/sock.c:2227)
     inet_create (net/ipv4/af_inet.c:326 net/ipv4/af_inet.c:252)
     __sock_create (net/socket.c:1576)
     generic_ip_connect (fs/smb/client/connect.c:3075)
     cifs_get_tcp_session.part.0 (fs/smb/client/connect.c:3160 fs/smb/client/connect.c:1798)
     cifs_mount_get_session (fs/smb/client/trace.h:959 fs/smb/client/connect.c:3366)
     dfs_mount_share (fs/smb/client/dfs.c:63 fs/smb/client/dfs.c:285)
     cifs_mount (fs/smb/client/connect.c:3622)
     cifs_smb3_do_mount (fs/smb/client/cifsfs.c:949)
     smb3_get_tree (fs/smb/client/fs_context.c:784 fs/smb/client/fs_context.c:802 fs/smb/client/fs_context.c:794)
     vfs_get_tree (fs/super.c:1800)
     path_mount (fs/namespace.c:3508 fs/namespace.c:3834)
     __x64_sys_mount (fs/namespace.c:3848 fs/namespace.c:4057 fs/namespace.c:4034 fs/namespace.c:4034)
     do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
     entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)

Fixes: 26abe14 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
Unloading the ice driver while switchdev port representors are added to
a bridge can lead to kernel panic. Reproducer:

  modprobe ice

  devlink dev eswitch set $PF1_PCI mode switchdev

  ip link add $BR type bridge
  ip link set $BR up

  echo 2 > /sys/class/net/$PF1/device/sriov_numvfs
  sleep 2

  ip link set $PF1 master $BR
  ip link set $VF1_PR master $BR
  ip link set $VF2_PR master $BR
  ip link set $PF1 up
  ip link set $VF1_PR up
  ip link set $VF2_PR up
  ip link set $VF1 up

  rmmod irdma ice

When unloading the driver, ice_eswitch_detach() is eventually called as
part of VF freeing. First, it removes a port representor from xarray,
then unregister_netdev() is called (via repr->ops.rem()), finally
representor is deallocated. The problem comes from the bridge doing its
own deinit at the same time. unregister_netdev() triggers a notifier
chain, resulting in ice_eswitch_br_port_deinit() being called. It should
set repr->br_port = NULL, but this does not happen since repr has
already been removed from xarray and is not found. Regardless, it
finishes up deallocating br_port. At this point, repr is still not freed
and an fdb event can happen, in which ice_eswitch_br_fdb_event_work()
takes repr->br_port and tries to use it, which causes a panic (use after
free).

Note that this only happens with 2 or more port representors added to
the bridge, since with only one representor port, the bridge deinit is
slightly different (ice_eswitch_br_port_deinit() is called via
ice_eswitch_br_ports_flush(), not ice_eswitch_br_port_unlink()).

Trace:
  Oops: general protection fault, probably for non-canonical address 0xf129010fd1a93284: 0000 [#1] PREEMPT SMP KASAN NOPTI
  KASAN: maybe wild-memory-access in range [0x8948287e8d499420-0x8948287e8d499427]
  (...)
  Workqueue: ice_bridge_wq ice_eswitch_br_fdb_event_work [ice]
  RIP: 0010:__rht_bucket_nested+0xb4/0x180
  (...)
  Call Trace:
   (...)
   ice_eswitch_br_fdb_find+0x3fa/0x550 [ice]
   ? __pfx_ice_eswitch_br_fdb_find+0x10/0x10 [ice]
   ice_eswitch_br_fdb_event_work+0x2de/0x1e60 [ice]
   ? __schedule+0xf60/0x5210
   ? mutex_lock+0x91/0xe0
   ? __pfx_ice_eswitch_br_fdb_event_work+0x10/0x10 [ice]
   ? ice_eswitch_br_update_work+0x1f4/0x310 [ice]
   (...)

A workaround is available: brctl setageing $BR 0, which stops the bridge
from adding fdb entries altogether.

Change the order of operations in ice_eswitch_detach(): move the call to
unregister_netdev() before removing repr from xarray. This way
repr->br_port will be correctly set to NULL in
ice_eswitch_br_port_deinit(), preventing a panic.

Fixes: fff292b ("ice: add VF representors one by one")
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
The RTC update work involves runtime resuming the UFS controller. Hence,
only start the RTC update work after runtime power management in the UFS
driver has been fully initialized. This patch fixes the following kernel
crash:

Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
Workqueue: events ufshcd_rtc_work
Call trace:
 _raw_spin_lock_irqsave+0x34/0x8c (P)
 pm_runtime_get_if_active+0x24/0x9c (L)
 pm_runtime_get_if_active+0x24/0x9c
 ufshcd_rtc_work+0x138/0x1b4
 process_one_work+0x148/0x288
 worker_thread+0x2cc/0x3d4
 kthread+0x110/0x114
 ret_from_fork+0x10/0x20

Reported-by: Neil Armstrong <neil.armstrong@linaro.org>
Closes: https://lore.kernel.org/linux-scsi/0c0bc528-fdc2-4106-bc99-f23ae377f6f5@linaro.org/
Fixes: 6bf999e ("scsi: ufs: core: Add UFS RTC support")
Cc: Bean Huo <beanhuo@micron.com>
Cc: stable@vger.kernel.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20241031212632.2799127-1-bvanassche@acm.org
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
In unlikely event that we fail during sending the new VF GGTT
configuration to the GuC, we will free only the GGTT node data
struct but will miss to release the actual GGTT allocation.

This will later lead to list corruption, GGTT space leak and
finally risking crash when unloading the driver:

 [ ] ... [drm] GT0: PF: Failed to provision VF1 with 1073741824 (1.00 GiB) GGTT (-EIO)
 [ ] ... [drm] GT0: PF: VF1 provisioning remains at 0 (0 B) GGTT

 [ ] list_add corruption. next->prev should be prev (ffff88813cfcd628), but was 0000000000000000. (next=ffff88813cfe2028).
 [ ] RIP: 0010:__list_add_valid_or_report+0x6b/0xb0
 [ ] Call Trace:
 [ ]  drm_mm_insert_node_in_range+0x2c0/0x4e0
 [ ]  xe_ggtt_node_insert+0x46/0x70 [xe]
 [ ]  pf_provision_vf_ggtt+0x7f5/0xa70 [xe]
 [ ]  xe_gt_sriov_pf_config_set_ggtt+0x5e/0x770 [xe]
 [ ]  ggtt_set+0x4b/0x70 [xe]
 [ ]  simple_attr_write_xsigned.constprop.0.isra.0+0xb0/0x110

 [ ] ... [drm] GT0: PF: Failed to provision VF1 with 1073741824 (1.00 GiB) GGTT (-ENOSPC)
 [ ] ... [drm] GT0: PF: VF1 provisioning remains at 0 (0 B) GGTT

 [ ] Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6b7b: 0000 [#1] PREEMPT SMP NOPTI
 [ ] RIP: 0010:drm_mm_remove_node+0x1b7/0x390
 [ ] Call Trace:
 [ ]  <TASK>
 [ ]  ? die_addr+0x2e/0x80
 [ ]  ? exc_general_protection+0x1a1/0x3e0
 [ ]  ? asm_exc_general_protection+0x22/0x30
 [ ]  ? drm_mm_remove_node+0x1b7/0x390
 [ ]  ggtt_node_remove+0xa5/0xf0 [xe]
 [ ]  xe_ggtt_node_remove+0x35/0x70 [xe]
 [ ]  xe_ttm_bo_destroy+0x123/0x220 [xe]
 [ ]  intel_user_framebuffer_destroy+0x44/0x70 [xe]
 [ ]  intel_plane_destroy_state+0x3b/0xc0 [xe]
 [ ]  drm_atomic_state_default_clear+0x1cd/0x2f0
 [ ]  intel_atomic_state_clear+0x9/0x20 [xe]
 [ ]  __drm_atomic_state_free+0x1d/0xb0

Fix that by using pf_release_ggtt() on the error path, which now
works regardless if the node has GGTT allocation or not.

Fixes: 34e8042 ("drm/xe: Make xe_ggtt_node struct independent")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241104144901.1903-1-michal.wajdeczko@intel.com
(cherry picked from commit 43b1dd2)
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
vp_modern_avq_cleanup() and vp_del_vqs() clean up admin vq
resources by virtio_pci_vq_info pointer. The info pointer of admin
vq is stored in vp_dev->admin_vq.info instead of vp_dev->vqs[].
Using the info pointer from vp_dev->vqs[] for admin vq causes a
kernel NULL pointer dereference bug.
In vp_modern_avq_cleanup() and vp_del_vqs(), get the info pointer
from vp_dev->admin_vq.info for admin vq to clean up the resources.
Also make info ptr as argument of vp_del_vq() to be symmetric with
vp_setup_vq().

vp_reset calls vp_modern_avq_cleanup, and causes the Call Trace:
==================================================================
BUG: kernel NULL pointer dereference, address:0000000000000000
...
CPU: 49 UID: 0 PID: 4439 Comm: modprobe Not tainted 6.11.0-rc5 #1
RIP: 0010:vp_reset+0x57/0x90 [virtio_pci]
Call Trace:
 <TASK>
...
 ? vp_reset+0x57/0x90 [virtio_pci]
 ? vp_reset+0x38/0x90 [virtio_pci]
 virtio_reset_device+0x1d/0x30
 remove_vq_common+0x1c/0x1a0 [virtio_net]
 virtnet_remove+0xa1/0xc0 [virtio_net]
 virtio_dev_remove+0x46/0xa0
...
 virtio_pci_driver_exit+0x14/0x810 [virtio_pci]
==================================================================

Fixes: 4c3b54a ("virtio_pci_modern: use completion instead of busy loop to wait on admin cmd result")
Signed-off-by: Feng Liu <feliu@nvidia.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Parav Pandit <parav@nvidia.com>
Message-Id: <20241024135406.81388-1-feliu@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
micromaomao pushed a commit that referenced this pull request Nov 24, 2024
In the error recovery path of mlx5_vdpa_dev_add(), the cleanup is
executed and at the end put_device() is called which ends up calling
mlx5_vdpa_free(). This function will execute the same cleanup all over
again. Most resources support being cleaned up twice, but the recent
mlx5_vdpa_destroy_mr_resources() doesn't.

This change drops the explicit cleanup from within the
mlx5_vdpa_dev_add() and lets mlx5_vdpa_free() do its work.

This issue was discovered while trying to add 2 vdpa devices with the
same name:
$> vdpa dev add name vdpa-0 mgmtdev auxiliary/mlx5_core.sf.2
$> vdpa dev add name vdpa-0 mgmtdev auxiliary/mlx5_core.sf.3

... yields the following dump:

  BUG: kernel NULL pointer dereference, address: 00000000000000b8
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  PGD 0 P4D 0
  Oops: Oops: 0000 [#1] SMP
  CPU: 4 UID: 0 PID: 2811 Comm: vdpa Not tainted 6.12.0-rc6 #1
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
  RIP: 0010:destroy_workqueue+0xe/0x2a0
  Code: ...
  RSP: 0018:ffff88814920b9a8 EFLAGS: 00010282
  RAX: 0000000000000000 RBX: ffff888105c10000 RCX: 0000000000000000
  RDX: 0000000000000001 RSI: ffff888100400168 RDI: 0000000000000000
  RBP: 0000000000000000 R08: ffff888100120c00 R09: ffffffff828578c0
  R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
  R13: ffff888131fd99a0 R14: 0000000000000000 R15: ffff888105c10580
  FS:  00007fdfa6b4f740(0000) GS:ffff88852ca00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000000000b8 CR3: 000000018db09006 CR4: 0000000000372eb0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   ? __die+0x20/0x60
   ? page_fault_oops+0x150/0x3e0
   ? exc_page_fault+0x74/0x130
   ? asm_exc_page_fault+0x22/0x30
   ? destroy_workqueue+0xe/0x2a0
   mlx5_vdpa_destroy_mr_resources+0x2b/0x40 [mlx5_vdpa]
   mlx5_vdpa_free+0x45/0x150 [mlx5_vdpa]
   vdpa_release_dev+0x1e/0x50 [vdpa]
   device_release+0x31/0x90
   kobject_put+0x8d/0x230
   mlx5_vdpa_dev_add+0x328/0x8b0 [mlx5_vdpa]
   vdpa_nl_cmd_dev_add_set_doit+0x2b8/0x4c0 [vdpa]
   genl_family_rcv_msg_doit+0xd0/0x120
   genl_rcv_msg+0x180/0x2b0
   ? __vdpa_alloc_device+0x1b0/0x1b0 [vdpa]
   ? genl_family_rcv_msg_dumpit+0xf0/0xf0
   netlink_rcv_skb+0x54/0x100
   genl_rcv+0x24/0x40
   netlink_unicast+0x1fc/0x2d0
   netlink_sendmsg+0x1e4/0x410
   __sock_sendmsg+0x38/0x60
   ? sockfd_lookup_light+0x12/0x60
   __sys_sendto+0x105/0x160
   ? __count_memcg_events+0x53/0xe0
   ? handle_mm_fault+0x100/0x220
   ? do_user_addr_fault+0x40d/0x620
   __x64_sys_sendto+0x20/0x30
   do_syscall_64+0x4c/0x100
   entry_SYSCALL_64_after_hwframe+0x4b/0x53
  RIP: 0033:0x7fdfa6c66b57
  Code: ...
  RSP: 002b:00007ffeace22998 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
  RAX: ffffffffffffffda RBX: 000055a498608350 RCX: 00007fdfa6c66b57
  RDX: 000000000000006c RSI: 000055a498608350 RDI: 0000000000000003
  RBP: 00007ffeace229c0 R08: 00007fdfa6d35200 R09: 000000000000000c
  R10: 0000000000000000 R11: 0000000000000202 R12: 000055a4986082a0
  R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffeace233f3
   </TASK>
  Modules linked in: ...
  CR2: 00000000000000b8

Fixes: 6211165 ("vdpa/mlx5: Postpone MR deletion")
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Message-Id: <20241105185101.1323272-2-dtatulea@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
micromaomao pushed a commit that referenced this pull request Nov 1, 2025
The chain allocator field cl_bpc (blocks per cluster) is read from disk
and used in division operations without validation.  A corrupted
filesystem image with cl_bpc=0 causes a divide-by-zero crash in the
kernel:

  divide error: 0000 [#1] PREEMPT SMP KASAN
  RIP: 0010:ocfs2_bg_discontig_add_extent fs/ocfs2/suballoc.c:335 [inline]
  RIP: 0010:ocfs2_block_group_fill+0x5bd/0xa70 fs/ocfs2/suballoc.c:386
  Call Trace:
   ocfs2_block_group_alloc+0x7e9/0x1330 fs/ocfs2/suballoc.c:703
   ocfs2_reserve_suballoc_bits+0x20a6/0x4640 fs/ocfs2/suballoc.c:834
   ocfs2_reserve_new_inode+0x4f4/0xcc0 fs/ocfs2/suballoc.c:1074
   ocfs2_mknod+0x83c/0x2050 fs/ocfs2/namei.c:306

This patch adds validation in ocfs2_validate_inode_block() to ensure
cl_bpc matches the expected value calculated from the superblock's cluster
size and block size for chain allocator inodes (identified by
OCFS2_CHAIN_FL).

Moving the validation to inode validation time (rather than allocation time)
has several benefits:
- Validates once when the inode is read, rather than on every allocation
- Protects all code paths that use cl_bpc (allocation, resize, etc.)
- Follows the existing pattern of inode validation in OCFS2
- Centralizes validation logic

The validation catches both:
- Zero values that cause divide-by-zero crashes
- Non-zero but incorrect values indicating filesystem corruption or
  mismatched filesystem geometry

With this fix, mounting a corrupted filesystem produces:
  OCFS2: ERROR (device loop0): ocfs2_validate_inode_block: Inode 74
         has corrupted cl_bpc: ondisk=0 expected=16

Instead of a kernel crash.

Link: https://lore.kernel.org/ocfs2-devel/20251026132625.12348-1-kartikey406@gmail.com/T/#u [v1]
Link: https://lore.kernel.org/all/20251027124131.10002-1-kartikey406@gmail.com/T/ [v2]
Link: https://lkml.kernel.org/r/20251028042919.18704-1-kartikey406@gmail.com
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reported-by: syzbot+fd8af97c7227fe605d95@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fd8af97c7227fe605d95
Tested-by: syzbot+fd8af97c7227fe605d95@syzkaller.appspotmail.com
Suggested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
micromaomao pushed a commit that referenced this pull request Nov 1, 2025
Ido Schimmel says:

====================
icmp: Add RFC 5837 support

tl;dr
=====

This patchset extends certain ICMP error messages (e.g., "Time
Exceeded") with incoming interface information in accordance with RFC
5837 [1]. This is required for more meaningful traceroute results in
unnumbered networks. Like other ICMP settings, the feature is controlled
via a per-{netns, address family} sysctl. The interface and the
implementation are designed to support more ICMP extensions.

Motivation
==========

Over the years, the kernel was extended with the ability to derive the
source IP of ICMP error messages from the interface that received the
datagram which elicited the ICMP error [2][3][4]. This is especially
important for "Time Exceeded" messages as it allows traceroute users to
trace the actual packet path along the network.

The above scheme does not work in unnumbered networks. In these
networks, only the loopback / VRF interface is assigned a global IP
address while router interfaces are assigned IPv6 link-local addresses.
As such, ICMP error messages are generated with a source IP derived from
the loopback / VRF interface, making it impossible to trace the actual
packet path when parallel links exist between routers.

The problem can be solved by implementing the solution proposed by RFC
4884 [5] and RFC 5837. The former defines an ICMP extension structure
that can be appended to selected ICMP messages and carry extension
objects. The latter defines an extension object called the "Interface
Information Object" (IIO) that can carry interface information (e.g.,
name, index, MTU) about interfaces with certain roles such as the
interface that received the datagram which elicited the ICMP error.

The payload of the datagram that elicited the error (potentially padded
/ trimmed) along with the ICMP extension structure will be queued to the
error queue of the originating socket, thereby allowing traceroute
applications to parse and display the information encoded in the ICMP
extension structure. Example:

 # traceroute6 -e 2001:db8:1::3
 traceroute to 2001:db8:1::3 (2001:db8:1::3), 30 hops max, 80 byte packets
  1  2001:db8:1::2 (2001:db8:1::2) <INC:11,"eth1",mtu=1500>  0.214 ms  0.171 ms  0.162 ms
  2  2001:db8:1::3 (2001:db8:1::3) <INC:12,"eth2",mtu=1500>  0.154 ms  0.135 ms  0.127 ms

 # traceroute -e 192.0.2.3
 traceroute to 192.0.2.3 (192.0.2.3), 30 hops max, 60 byte packets
  1  192.0.2.2 (192.0.2.2) <INC:11,"eth1",mtu=1500>  0.191 ms  0.148 ms  0.144 ms
  2  192.0.2.3 (192.0.2.3) <INC:12,"eth2",mtu=1500>  0.137 ms  0.122 ms  0.114 ms

Implementation
==============

As previously stated, the feature is controlled via a per-{netns,
address} sysctl. Specifically, a bit mask where each bit controls the
addition of a different ICMP extension to ICMP error messages.
Currently, only a single value is supported, to append the incoming
interface information.

Key points:

1. Global knob vs finer control. I am not aware of users who require
finer control, but it is possible that some users will want to avoid
appending ICMP extensions when the packet is sent out of a specific
interface (e.g., the management interface) or to a specific subnet. This
can be accomplished via a tc-bpf program that trims the ICMP extension
structure. An example program can be found here [6].

2. Split implementation between IPv4 / IPv6. While the implementation is
currently similar, there are some differences between both address
families. In addition, some extensions (e.g., RFC 8883 [7]) are
IPv6-specific. Given the above and given that the implementation is not
very complex, it makes sense to keep both implementations separate.

3. Compatibility with legacy applications. RFC 4884 from 2007 extended
certain ICMP messages with a length field that encodes the length of the
"original datagram" field, so that applications will be able to tell
where the "original datagram" ends and where the ICMP extension
structure starts.

Before the introduction of the IP{,6}_RECVERR_RFC4884 socket options
[8][9] in 2020 it was impossible for applications to know where the ICMP
extension structure starts and to this day some applications assume that
it starts at offset 128, which is the minimum length of the "original
datagram" field as specified by RFC 4884.

Therefore, in order to be compatible with both legacy and modern
applications, the datagram that elicited the ICMP error is trimmed /
padded to 128 bytes before appending the ICMP extension structure.

This behavior is specifically called out by RFC 4884: "Those wishing to
be backward compatible with non-compliant TRACEROUTE implementations
will include exactly 128 octets" [10].

Note that in 128 bytes we should be able to include enough headers for
the originating node to match the ICMP error message with the relevant
socket. For example, the following headers will be present in the
"original datagram" field when a VXLAN encapsulated IPv6 packet elicits
an ICMP error in an IPv6 underlay: IPv6 (40) | UDP (8) | VXLAN (8) | Eth
(14) | IPv6 (40) | UDP (8). Overall, 118 bytes.

If the 128 bytes limit proves to be insufficient for some use case, we
can consider dedicating a new bit in the previously mentioned sysctl to
allow for more bytes to be included in the "original datagram" field.

4. Extensibility. This patchset adds partial support for a single ICMP
extension. However, the interface and the implementation should be able
to support more extensions, if needed. Examples:

* More interface information objects as part of RFC 5837. We should be
  able to derive the outgoing interface information and nexthop IP from
  the dst entry attached to the packet that elicited the error.

* Node identification object (e.g., hostname / loopback IP) [11].

* Extended Information object which encodes aggregate header limits as
  part of RFC 8883.

A previous proposal from Ishaan Gandhi and Ron Bonica is available here
[12].

Testing
=======

The existing traceroute selftest is extended to test that ICMP
extensions are reported correctly when enabled. Both address families
are tested and with different packet sizes in order to make sure that
trimming / padding works correctly. Tested that packets are parsed
correctly by the IP{,6}_RECVERR_RFC4884 socket options using Willem's
selftest [13].

Changelog
=========

Changes since v1 [14]:

* Patches #1-#2: Added a comment about field ordering and review tags.

* Patch #3: Converted "sysctl" to "echo" when testing the return value.
  Added a check to skip the test if traceroute version is older
  than 2.1.5.

[1] https://datatracker.ietf.org/doc/html/rfc5837
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1c2fb7f93cb20621772bf304f3dba0849942e5db
[3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fac6fce9bdb59837bb89930c3a92f5e0d1482f0b
[4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4a8c416602d97a4e2073ed563d4d4c7627de19cf
[5] https://datatracker.ietf.org/doc/html/rfc4884
[6] https://gist.github.com/idosch/5013448cdb5e9e060e6bfdc8b433577c
[7] https://datatracker.ietf.org/doc/html/rfc8883
[8] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eba75c587e811d3249c8bd50d22bb2266ccd3c0f
[9] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=01370434df85eb76ecb1527a4466013c4aca2436
[10] https://datatracker.ietf.org/doc/html/rfc4884#section-5.3
[11] https://datatracker.ietf.org/doc/html/draft-ietf-intarea-extended-icmp-nodeid-04
[12] https://lore.kernel.org/netdev/20210317221959.4410-1-ishaangandhi@gmail.com/
[13] https://lore.kernel.org/netdev/aPpMItF35gwpgzZx@shredder/
[14] https://lore.kernel.org/netdev/20251022065349.434123-1-idosch@nvidia.com/
====================

Link: https://patch.msgid.link/20251027082232.232571-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 6, 2025
This reverts commit d02c2e4.

Mauro reports that this breaks APEI notifications on his QEMU setup
because the "reserved for firmware" region still needs to be writable
by Linux in order to signal _back_ to the firmware after processing
the reported error:

  | {1}[Hardware Error]: Hardware error from APEI Generic Hardware Error Source: 1
  | ...
  | [Firmware Warn]: GHES: Unhandled processor error type 0x02: cache error
  | Unable to handle kernel write to read-only memory at virtual address ffff800080035018
  | Mem abort info:
  |   ESR = 0x000000009600004f
  |   EC = 0x25: DABT (current EL), IL = 32 bits
  |   SET = 0, FnV = 0
  |   EA = 0, S1PTW = 0
  |   FSC = 0x0f: level 3 permission fault
  | Data abort info:
  |   ISV = 0, ISS = 0x0000004f, ISS2 = 0x00000000
  |   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
  |   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
  | swapper pgtable: 4k pages, 52-bit VAs, pgdp=00000000505d7000
  | pgd=10000000510bc003, p4d=1000000100229403, pud=100000010022a403, pmd=100000010022b403, pte=0060000139b90483
  | Internal error: Oops: 000000009600004f [#1]  SMP

For now, revert the offending commit. We can presumably switch back to
PAGE_KERNEL when bringing this back in the future.

Link: https://lore.kernel.org/r/20251121224611.07efa95a@foz.lan
Reported-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 6, 2025
Since commit 30f241f ("xsk: Fix immature cq descriptor
production"), the descriptor number is stored in skb control block and
xsk_cq_submit_addr_locked() relies on it to put the umem addrs onto
pool's completion queue.

skb control block shouldn't be used for this purpose as after transmit
xsk doesn't have control over it and other subsystems could use it. This
leads to the following kernel panic due to a NULL pointer dereference.

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 2 UID: 1 PID: 927 Comm: p4xsk.bin Not tainted 6.16.12+deb14-cloud-amd64 #1 PREEMPT(lazy)  Debian 6.16.12-1
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
 RIP: 0010:xsk_destruct_skb+0xd0/0x180
 [...]
 Call Trace:
  <IRQ>
  ? napi_complete_done+0x7a/0x1a0
  ip_rcv_core+0x1bb/0x340
  ip_rcv+0x30/0x1f0
  __netif_receive_skb_one_core+0x85/0xa0
  process_backlog+0x87/0x130
  __napi_poll+0x28/0x180
  net_rx_action+0x339/0x420
  handle_softirqs+0xdc/0x320
  ? handle_edge_irq+0x90/0x1e0
  do_softirq.part.0+0x3b/0x60
  </IRQ>
  <TASK>
  __local_bh_enable_ip+0x60/0x70
  __dev_direct_xmit+0x14e/0x1f0
  __xsk_generic_xmit+0x482/0xb70
  ? __remove_hrtimer+0x41/0xa0
  ? __xsk_generic_xmit+0x51/0xb70
  ? _raw_spin_unlock_irqrestore+0xe/0x40
  xsk_sendmsg+0xda/0x1c0
  __sys_sendto+0x1ee/0x200
  __x64_sys_sendto+0x24/0x30
  do_syscall_64+0x84/0x2f0
  ? __pfx_pollwake+0x10/0x10
  ? __rseq_handle_notify_resume+0xad/0x4c0
  ? restore_fpregs_from_fpstate+0x3c/0x90
  ? switch_fpu_return+0x5b/0xe0
  ? do_syscall_64+0x204/0x2f0
  ? do_syscall_64+0x204/0x2f0
  ? do_syscall_64+0x204/0x2f0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e
  </TASK>
 [...]
 Kernel panic - not syncing: Fatal exception in interrupt
 Kernel Offset: 0x1c000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Instead use the skb destructor_arg pointer along with pointer tagging.
As pointers are always aligned to 8B, use the bottom bit to indicate
whether this a single address or an allocated struct containing several
addresses.

Fixes: 30f241f ("xsk: Fix immature cq descriptor production")
Closes: https://lore.kernel.org/netdev/0435b904-f44f-48f8-afb0-68868474bf1c@nop.hu/
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://patch.msgid.link/20251124171409.3845-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 6, 2025
…ptcp_do_fastclose().

syzbot reported divide-by-zero in __tcp_select_window() by
MPTCP socket. [0]

We had a similar issue for the bare TCP and fixed in commit
499350a ("tcp: initialize rcv_mss to TCP_MIN_MSS instead
of 0").

Let's apply the same fix to mptcp_do_fastclose().

[0]:
Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6068 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__tcp_select_window+0x824/0x1320 net/ipv4/tcp_output.c:3336
Code: ff ff ff 44 89 f1 d3 e0 89 c1 f7 d1 41 01 cc 41 21 c4 e9 a9 00 00 00 e8 ca 49 01 f8 e9 9c 00 00 00 e8 c0 49 01 f8 44 89 e0 99 <f7> 7c 24 1c 41 29 d4 48 bb 00 00 00 00 00 fc ff df e9 80 00 00 00
RSP: 0018:ffffc90003017640 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807b469e40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003017730 R08: ffff888033268143 R09: 1ffff1100664d028
R10: dffffc0000000000 R11: ffffed100664d029 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  000055557faa0500(0000) GS:ffff888126135000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64a1912ff8 CR3: 0000000072122000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 tcp_select_window net/ipv4/tcp_output.c:281 [inline]
 __tcp_transmit_skb+0xbc7/0x3aa0 net/ipv4/tcp_output.c:1568
 tcp_transmit_skb net/ipv4/tcp_output.c:1649 [inline]
 tcp_send_active_reset+0x2d1/0x5b0 net/ipv4/tcp_output.c:3836
 mptcp_do_fastclose+0x27e/0x380 net/mptcp/protocol.c:2793
 mptcp_disconnect+0x238/0x710 net/mptcp/protocol.c:3253
 mptcp_sendmsg_fastopen+0x2f8/0x580 net/mptcp/protocol.c:1776
 mptcp_sendmsg+0x1774/0x1980 net/mptcp/protocol.c:1855
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0xe5/0x270 net/socket.c:742
 __sys_sendto+0x3bd/0x520 net/socket.c:2244
 __do_sys_sendto net/socket.c:2251 [inline]
 __se_sys_sendto net/socket.c:2247 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2247
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f66e998f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff9acedb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f66e9be5fa0 RCX: 00007f66e998f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffff9acee10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f66e9be5fa0 R14: 00007f66e9be5fa0 R15: 0000000000000006
 </TASK>

Fixes: ae15506 ("mptcp: fix duplicate reset on fastclose")
Reported-by: syzbot+3a92d359bc2ec6255a33@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69260882.a70a0220.d98e3.00b4.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251125195331.309558-1-kuniyu@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
micromaomao pushed a commit that referenced this pull request Dec 6, 2025
The crash in process_v2_sparse_read() for fscrypt-encrypted directories
has been reported. Issue takes place for Ceph msgr2 protocol in secure
mode. It can be reproduced by the steps:

sudo mount -t ceph :/ /mnt/cephfs/ -o name=admin,fs=cephfs,ms_mode=secure

(1) mkdir /mnt/cephfs/fscrypt-test-3
(2) cp area_decrypted.tar /mnt/cephfs/fscrypt-test-3
(3) fscrypt encrypt --source=raw_key --key=./my.key /mnt/cephfs/fscrypt-test-3
(4) fscrypt lock /mnt/cephfs/fscrypt-test-3
(5) fscrypt unlock --key=my.key /mnt/cephfs/fscrypt-test-3
(6) cat /mnt/cephfs/fscrypt-test-3/area_decrypted.tar
(7) Issue has been triggered

[  408.072247] ------------[ cut here ]------------
[  408.072251] WARNING: CPU: 1 PID: 392 at net/ceph/messenger_v2.c:865
ceph_con_v2_try_read+0x4b39/0x72f0
[  408.072267] Modules linked in: intel_rapl_msr intel_rapl_common
intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_discovery
pmt_class intel_pmc_ssram_telemetry intel_vsec kvm_intel joydev kvm irqbypass
polyval_clmulni ghash_clmulni_intel aesni_intel rapl input_leds psmouse
serio_raw i2c_piix4 vga16fb bochs vgastate i2c_smbus floppy mac_hid qemu_fw_cfg
pata_acpi sch_fq_codel rbd msr parport_pc ppdev lp parport efi_pstore
[  408.072304] CPU: 1 UID: 0 PID: 392 Comm: kworker/1:3 Not tainted 6.17.0-rc7+
[  408.072307] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.17.0-5.fc42 04/01/2014
[  408.072310] Workqueue: ceph-msgr ceph_con_workfn
[  408.072314] RIP: 0010:ceph_con_v2_try_read+0x4b39/0x72f0
[  408.072317] Code: c7 c1 20 f0 d4 ae 50 31 d2 48 c7 c6 60 27 d5 ae 48 c7 c7 f8
8e 6f b0 68 60 38 d5 ae e8 00 47 61 fe 48 83 c4 18 e9 ac fc ff ff <0f> 0b e9 06
fe ff ff 4c 8b 9d 98 fd ff ff 0f 84 64 e7 ff ff 89 85
[  408.072319] RSP: 0018:ffff88811c3e7a30 EFLAGS: 00010246
[  408.072322] RAX: ffffed1024874c6f RBX: ffffea00042c2b40 RCX: 0000000000000f38
[  408.072324] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  408.072325] RBP: ffff88811c3e7ca8 R08: 0000000000000000 R09: 00000000000000c8
[  408.072326] R10: 00000000000000c8 R11: 0000000000000000 R12: 00000000000000c8
[  408.072327] R13: dffffc0000000000 R14: ffff8881243a6030 R15: 0000000000003000
[  408.072329] FS:  0000000000000000(0000) GS:ffff88823eadf000(0000)
knlGS:0000000000000000
[  408.072331] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  408.072332] CR2: 000000c0003c6000 CR3: 000000010c106005 CR4: 0000000000772ef0
[  408.072336] PKRU: 55555554
[  408.072337] Call Trace:
[  408.072338]  <TASK>
[  408.072340]  ? sched_clock_noinstr+0x9/0x10
[  408.072344]  ? __pfx_ceph_con_v2_try_read+0x10/0x10
[  408.072347]  ? _raw_spin_unlock+0xe/0x40
[  408.072349]  ? finish_task_switch.isra.0+0x15d/0x830
[  408.072353]  ? __kasan_check_write+0x14/0x30
[  408.072357]  ? mutex_lock+0x84/0xe0
[  408.072359]  ? __pfx_mutex_lock+0x10/0x10
[  408.072361]  ceph_con_workfn+0x27e/0x10e0
[  408.072364]  ? metric_delayed_work+0x311/0x2c50
[  408.072367]  process_one_work+0x611/0xe20
[  408.072371]  ? __kasan_check_write+0x14/0x30
[  408.072373]  worker_thread+0x7e3/0x1580
[  408.072375]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  408.072378]  ? __pfx_worker_thread+0x10/0x10
[  408.072381]  kthread+0x381/0x7a0
[  408.072383]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  408.072385]  ? __pfx_kthread+0x10/0x10
[  408.072387]  ? __kasan_check_write+0x14/0x30
[  408.072389]  ? recalc_sigpending+0x160/0x220
[  408.072392]  ? _raw_spin_unlock_irq+0xe/0x50
[  408.072394]  ? calculate_sigpending+0x78/0xb0
[  408.072395]  ? __pfx_kthread+0x10/0x10
[  408.072397]  ret_from_fork+0x2b6/0x380
[  408.072400]  ? __pfx_kthread+0x10/0x10
[  408.072402]  ret_from_fork_asm+0x1a/0x30
[  408.072406]  </TASK>
[  408.072407] ---[ end trace 0000000000000000 ]---
[  408.072418] Oops: general protection fault, probably for non-canonical
address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
[  408.072984] KASAN: null-ptr-deref in range [0x0000000000000000-
0x0000000000000007]
[  408.073350] CPU: 1 UID: 0 PID: 392 Comm: kworker/1:3 Tainted: G        W
6.17.0-rc7+ #1 PREEMPT(voluntary)
[  408.073886] Tainted: [W]=WARN
[  408.074042] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.17.0-5.fc42 04/01/2014
[  408.074468] Workqueue: ceph-msgr ceph_con_workfn
[  408.074694] RIP: 0010:ceph_msg_data_advance+0x79/0x1a80
[  408.074976] Code: fc ff df 49 8d 77 08 48 c1 ee 03 80 3c 16 00 0f 85 07 11 00
00 48 ba 00 00 00 00 00 fc ff df 49 8b 5f 08 48 89 de 48 c1 ee 03 <0f> b6 14 16
84 d2 74 09 80 fa 03 0f 8e 0f 0e 00 00 8b 13 83 fa 03
[  408.075884] RSP: 0018:ffff88811c3e7990 EFLAGS: 00010246
[  408.076305] RAX: ffff8881243a6388 RBX: 0000000000000000 RCX: 0000000000000000
[  408.076909] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8881243a6378
[  408.077466] RBP: ffff88811c3e7a20 R08: 0000000000000000 R09: 00000000000000c8
[  408.078034] R10: ffff8881243a6388 R11: 0000000000000000 R12: ffffed1024874c71
[  408.078575] R13: dffffc0000000000 R14: ffff8881243a6030 R15: ffff8881243a6378
[  408.079159] FS:  0000000000000000(0000) GS:ffff88823eadf000(0000)
knlGS:0000000000000000
[  408.079736] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  408.080039] CR2: 000000c0003c6000 CR3: 000000010c106005 CR4: 0000000000772ef0
[  408.080376] PKRU: 55555554
[  408.080513] Call Trace:
[  408.080630]  <TASK>
[  408.080729]  ceph_con_v2_try_read+0x49b9/0x72f0
[  408.081115]  ? __pfx_ceph_con_v2_try_read+0x10/0x10
[  408.081348]  ? _raw_spin_unlock+0xe/0x40
[  408.081538]  ? finish_task_switch.isra.0+0x15d/0x830
[  408.081768]  ? __kasan_check_write+0x14/0x30
[  408.081986]  ? mutex_lock+0x84/0xe0
[  408.082160]  ? __pfx_mutex_lock+0x10/0x10
[  408.082343]  ceph_con_workfn+0x27e/0x10e0
[  408.082529]  ? metric_delayed_work+0x311/0x2c50
[  408.082737]  process_one_work+0x611/0xe20
[  408.082948]  ? __kasan_check_write+0x14/0x30
[  408.083156]  worker_thread+0x7e3/0x1580
[  408.083331]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  408.083557]  ? __pfx_worker_thread+0x10/0x10
[  408.083751]  kthread+0x381/0x7a0
[  408.083922]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  408.084139]  ? __pfx_kthread+0x10/0x10
[  408.084310]  ? __kasan_check_write+0x14/0x30
[  408.084510]  ? recalc_sigpending+0x160/0x220
[  408.084708]  ? _raw_spin_unlock_irq+0xe/0x50
[  408.084917]  ? calculate_sigpending+0x78/0xb0
[  408.085138]  ? __pfx_kthread+0x10/0x10
[  408.085335]  ret_from_fork+0x2b6/0x380
[  408.085525]  ? __pfx_kthread+0x10/0x10
[  408.085720]  ret_from_fork_asm+0x1a/0x30
[  408.085922]  </TASK>
[  408.086036] Modules linked in: intel_rapl_msr intel_rapl_common
intel_uncore_frequency_common intel_pmc_core pmt_telemetry pmt_discovery
pmt_class intel_pmc_ssram_telemetry intel_vsec kvm_intel joydev kvm irqbypass
polyval_clmulni ghash_clmulni_intel aesni_intel rapl input_leds psmouse
serio_raw i2c_piix4 vga16fb bochs vgastate i2c_smbus floppy mac_hid qemu_fw_cfg
pata_acpi sch_fq_codel rbd msr parport_pc ppdev lp parport efi_pstore
[  408.087778] ---[ end trace 0000000000000000 ]---
[  408.088007] RIP: 0010:ceph_msg_data_advance+0x79/0x1a80
[  408.088260] Code: fc ff df 49 8d 77 08 48 c1 ee 03 80 3c 16 00 0f 85 07 11 00
00 48 ba 00 00 00 00 00 fc ff df 49 8b 5f 08 48 89 de 48 c1 ee 03 <0f> b6 14 16
84 d2 74 09 80 fa 03 0f 8e 0f 0e 00 00 8b 13 83 fa 03
[  408.089118] RSP: 0018:ffff88811c3e7990 EFLAGS: 00010246
[  408.089357] RAX: ffff8881243a6388 RBX: 0000000000000000 RCX: 0000000000000000
[  408.089678] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff8881243a6378
[  408.090020] RBP: ffff88811c3e7a20 R08: 0000000000000000 R09: 00000000000000c8
[  408.090360] R10: ffff8881243a6388 R11: 0000000000000000 R12: ffffed1024874c71
[  408.090687] R13: dffffc0000000000 R14: ffff8881243a6030 R15: ffff8881243a6378
[  408.091035] FS:  0000000000000000(0000) GS:ffff88823eadf000(0000)
knlGS:0000000000000000
[  408.091452] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  408.092015] CR2: 000000c0003c6000 CR3: 000000010c106005 CR4: 0000000000772ef0
[  408.092530] PKRU: 55555554
[  417.112915]
==================================================================
[  417.113491] BUG: KASAN: slab-use-after-free in
__mutex_lock.constprop.0+0x1522/0x1610
[  417.114014] Read of size 4 at addr ffff888124870034 by task kworker/2:0/4951

[  417.114587] CPU: 2 UID: 0 PID: 4951 Comm: kworker/2:0 Tainted: G      D W
6.17.0-rc7+ #1 PREEMPT(voluntary)
[  417.114592] Tainted: [D]=DIE, [W]=WARN
[  417.114593] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.17.0-5.fc42 04/01/2014
[  417.114596] Workqueue: events handle_timeout
[  417.114601] Call Trace:
[  417.114602]  <TASK>
[  417.114604]  dump_stack_lvl+0x5c/0x90
[  417.114610]  print_report+0x171/0x4dc
[  417.114613]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  417.114617]  ? kasan_complete_mode_report_info+0x80/0x220
[  417.114621]  kasan_report+0xbd/0x100
[  417.114625]  ? __mutex_lock.constprop.0+0x1522/0x1610
[  417.114628]  ? __mutex_lock.constprop.0+0x1522/0x1610
[  417.114630]  __asan_report_load4_noabort+0x14/0x30
[  417.114633]  __mutex_lock.constprop.0+0x1522/0x1610
[  417.114635]  ? queue_con_delay+0x8d/0x200
[  417.114638]  ? __pfx___mutex_lock.constprop.0+0x10/0x10
[  417.114641]  ? __send_subscribe+0x529/0xb20
[  417.114644]  __mutex_lock_slowpath+0x13/0x20
[  417.114646]  mutex_lock+0xd4/0xe0
[  417.114649]  ? __pfx_mutex_lock+0x10/0x10
[  417.114652]  ? ceph_monc_renew_subs+0x2a/0x40
[  417.114654]  ceph_con_keepalive+0x22/0x110
[  417.114656]  handle_timeout+0x6b3/0x11d0
[  417.114659]  ? _raw_spin_unlock_irq+0xe/0x50
[  417.114662]  ? __pfx_handle_timeout+0x10/0x10
[  417.114664]  ? queue_delayed_work_on+0x8e/0xa0
[  417.114669]  process_one_work+0x611/0xe20
[  417.114672]  ? __kasan_check_write+0x14/0x30
[  417.114676]  worker_thread+0x7e3/0x1580
[  417.114678]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  417.114682]  ? __pfx_sched_setscheduler_nocheck+0x10/0x10
[  417.114687]  ? __pfx_worker_thread+0x10/0x10
[  417.114689]  kthread+0x381/0x7a0
[  417.114692]  ? __pfx__raw_spin_lock_irq+0x10/0x10
[  417.114694]  ? __pfx_kthread+0x10/0x10
[  417.114697]  ? __kasan_check_write+0x14/0x30
[  417.114699]  ? recalc_sigpending+0x160/0x220
[  417.114703]  ? _raw_spin_unlock_irq+0xe/0x50
[  417.114705]  ? calculate_sigpending+0x78/0xb0
[  417.114707]  ? __pfx_kthread+0x10/0x10
[  417.114710]  ret_from_fork+0x2b6/0x380
[  417.114713]  ? __pfx_kthread+0x10/0x10
[  417.114715]  ret_from_fork_asm+0x1a/0x30
[  417.114720]  </TASK>

[  417.125171] Allocated by task 2:
[  417.125333]  kasan_save_stack+0x26/0x60
[  417.125522]  kasan_save_track+0x14/0x40
[  417.125742]  kasan_save_alloc_info+0x39/0x60
[  417.125945]  __kasan_slab_alloc+0x8b/0xb0
[  417.126133]  kmem_cache_alloc_node_noprof+0x13b/0x460
[  417.126381]  copy_process+0x320/0x6250
[  417.126595]  kernel_clone+0xb7/0x840
[  417.126792]  kernel_thread+0xd6/0x120
[  417.126995]  kthreadd+0x85c/0xbe0
[  417.127176]  ret_from_fork+0x2b6/0x380
[  417.127378]  ret_from_fork_asm+0x1a/0x30

[  417.127692] Freed by task 0:
[  417.127851]  kasan_save_stack+0x26/0x60
[  417.128057]  kasan_save_track+0x14/0x40
[  417.128267]  kasan_save_free_info+0x3b/0x60
[  417.128491]  __kasan_slab_free+0x6c/0xa0
[  417.128708]  kmem_cache_free+0x182/0x550
[  417.128906]  free_task+0xeb/0x140
[  417.129070]  __put_task_struct+0x1d2/0x4f0
[  417.129259]  __put_task_struct_rcu_cb+0x15/0x20
[  417.129480]  rcu_do_batch+0x3d3/0xe70
[  417.129681]  rcu_core+0x549/0xb30
[  417.129839]  rcu_core_si+0xe/0x20
[  417.130005]  handle_softirqs+0x160/0x570
[  417.130190]  __irq_exit_rcu+0x189/0x1e0
[  417.130369]  irq_exit_rcu+0xe/0x20
[  417.130531]  sysvec_apic_timer_interrupt+0x9f/0xd0
[  417.130768]  asm_sysvec_apic_timer_interrupt+0x1b/0x20

[  417.131082] Last potentially related work creation:
[  417.131305]  kasan_save_stack+0x26/0x60
[  417.131484]  kasan_record_aux_stack+0xae/0xd0
[  417.131695]  __call_rcu_common+0xcd/0x14b0
[  417.131909]  call_rcu+0x31/0x50
[  417.132071]  delayed_put_task_struct+0x128/0x190
[  417.132295]  rcu_do_batch+0x3d3/0xe70
[  417.132478]  rcu_core+0x549/0xb30
[  417.132658]  rcu_core_si+0xe/0x20
[  417.132808]  handle_softirqs+0x160/0x570
[  417.132993]  __irq_exit_rcu+0x189/0x1e0
[  417.133181]  irq_exit_rcu+0xe/0x20
[  417.133353]  sysvec_apic_timer_interrupt+0x9f/0xd0
[  417.133584]  asm_sysvec_apic_timer_interrupt+0x1b/0x20

[  417.133921] Second to last potentially related work creation:
[  417.134183]  kasan_save_stack+0x26/0x60
[  417.134362]  kasan_record_aux_stack+0xae/0xd0
[  417.134566]  __call_rcu_common+0xcd/0x14b0
[  417.134782]  call_rcu+0x31/0x50
[  417.134929]  put_task_struct_rcu_user+0x58/0xb0
[  417.135143]  finish_task_switch.isra.0+0x5d3/0x830
[  417.135366]  __schedule+0xd30/0x5100
[  417.135534]  schedule_idle+0x5a/0x90
[  417.135712]  do_idle+0x25f/0x410
[  417.135871]  cpu_startup_entry+0x53/0x70
[  417.136053]  start_secondary+0x216/0x2c0
[  417.136233]  common_startup_64+0x13e/0x141

[  417.136894] The buggy address belongs to the object at ffff888124870000
                which belongs to the cache task_struct of size 10504
[  417.138122] The buggy address is located 52 bytes inside of
                freed 10504-byte region [ffff888124870000, ffff888124872908)

[  417.139465] The buggy address belongs to the physical page:
[  417.140016] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
pfn:0x124870
[  417.140789] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0
pincount:0
[  417.141519] memcg:ffff88811aa20e01
[  417.141874] anon flags:
0x17ffffc0000040(head|node=0|zone=2|lastcpupid=0x1fffff)
[  417.142600] page_type: f5(slab)
[  417.142922] raw: 0017ffffc0000040 ffff88810094f040 0000000000000000
dead000000000001
[  417.143554] raw: 0000000000000000 0000000000030003 00000000f5000000
ffff88811aa20e01
[  417.143954] head: 0017ffffc0000040 ffff88810094f040 0000000000000000
dead000000000001
[  417.144329] head: 0000000000000000 0000000000030003 00000000f5000000
ffff88811aa20e01
[  417.144710] head: 0017ffffc0000003 ffffea0004921c01 00000000ffffffff
00000000ffffffff
[  417.145106] head: ffffffffffffffff 0000000000000000 00000000ffffffff
0000000000000008
[  417.145485] page dumped because: kasan: bad access detected

[  417.145859] Memory state around the buggy address:
[  417.146094]  ffff88812486ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
fc
[  417.146439]  ffff88812486ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
fc
[  417.146791] >ffff888124870000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb
[  417.147145]                                      ^
[  417.147387]  ffff888124870080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb
[  417.147751]  ffff888124870100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
fb
[  417.148123]
==================================================================

First of all, we have warning in get_bvec_at() because
cursor->total_resid contains zero value. And, finally,
we have crash in ceph_msg_data_advance() because
cursor->data is NULL. It means that get_bvec_at()
receives not initialized ceph_msg_data_cursor structure
because data is NULL and total_resid contains zero.

Moreover, we don't have likewise issue for the case of
Ceph msgr1 protocol because ceph_msg_data_cursor_init()
has been called before reading sparse data.

This patch adds calling of ceph_msg_data_cursor_init()
in the beginning of process_v2_sparse_read() with
the goal to guarantee that logic of reading sparse data
works correctly for the case of Ceph msgr2 protocol.

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/73152
Signed-off-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
micromaomao pushed a commit that referenced this pull request Dec 6, 2025
[WHAT]
IGT kms_cursor_legacy's long-nonblocking-modeset-vs-cursor-atomic
fails with NULL pointer dereference. This can be reproduced with
both an eDP panel and a DP monitors connected.

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 13 UID: 0 PID: 2960 Comm: kms_cursor_lega Not tainted
6.16.0-99-custom #8 PREEMPT(voluntary)
 Hardware name: AMD ........
 RIP: 0010:dc_stream_get_scanoutpos+0x34/0x130 [amdgpu]
 Code: 57 4d 89 c7 41 56 49 89 ce 41 55 49 89 d5 41 54 49
 89 fc 53 48 83 ec 18 48 8b 87 a0 64 00 00 48 89 75 d0 48 c7 c6 e0 41 30
 c2 <48> 8b 38 48 8b 9f 68 06 00 00 e8 8d d7 fd ff 31 c0 48 81 c3 e0 02
 RSP: 0018:ffffd0f3c2bd7608 EFLAGS: 00010292
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffd0f3c2bd7668
 RDX: ffffd0f3c2bd7664 RSI: ffffffffc23041e0 RDI: ffff8b32494b8000
 RBP: ffffd0f3c2bd7648 R08: ffffd0f3c2bd766c R09: ffffd0f3c2bd7760
 R10: ffffd0f3c2bd7820 R11: 0000000000000000 R12: ffff8b32494b8000
 R13: ffffd0f3c2bd7664 R14: ffffd0f3c2bd7668 R15: ffffd0f3c2bd766c
 FS:  000071f631b68700(0000) GS:ffff8b399f114000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000001b8105000 CR4: 0000000000f50ef0
 PKRU: 55555554
 Call Trace:
 <TASK>
 dm_crtc_get_scanoutpos+0xd7/0x180 [amdgpu]
 amdgpu_display_get_crtc_scanoutpos+0x86/0x1c0 [amdgpu]
 ? __pfx_amdgpu_crtc_get_scanout_position+0x10/0x10[amdgpu]
 amdgpu_crtc_get_scanout_position+0x27/0x50 [amdgpu]
 drm_crtc_vblank_helper_get_vblank_timestamp_internal+0xf7/0x400
 drm_crtc_vblank_helper_get_vblank_timestamp+0x1c/0x30
 drm_crtc_get_last_vbltimestamp+0x55/0x90
 drm_crtc_next_vblank_start+0x45/0xa0
 drm_atomic_helper_wait_for_fences+0x81/0x1f0
 ...

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 621e55f)
Cc: stable@vger.kernel.org
micromaomao added a commit that referenced this pull request Dec 6, 2025
virtio-serial does not work with kgdboc.  I know it's an unusual use case
as one can always just use the qemu gdbserver, but still...

root@aa98fce09d67:/# echo a > /dev/hvc0
root@aa98fce09d67:/# echo a > /dev/hvc1
a
root@aa98fce09d67:/# echo g > /proc/sysrq-trigger
[   11.997004][  T146] sysrq: DEBUG
[   11.998003][    C9] BUG: kernel NULL pointer dereference, address: 0000000000000248
[   11.998003][    C9] #PF: supervisor read access in kernel mode
[   11.998003][    C9] #PF: error_code(0x0000) - not-present page
[   11.998003][    C9] PGD 0 P4D 0
[   11.998003][    C9] Oops: Oops: 0000 [#1] PREEMPT SMP
[   11.998003][    C9] CPU: 9 UID: 0 PID: 146 Comm: bash Not tainted 6.14.0-dev-00032-g11aa3e204678-dirty torvalds#122
[   11.998003][    C9] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 11.998003][ C9] RIP: 0010:hvc_poll_put_char (drivers/tty/hvc/hvc_console.c:879)
[ 11.998003][ C9] Code: 00 00 ff 00 eb e8 e8 e0 7d 2a 00 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 53 48 83 ec 08 48 8b 87 80 00 00 00 88 55 f4 48 8b 00 <48> 8b 98 48 02 00 00 48 8b 83 90 01 00 00 8b bb 8c 01 00 00 ba 01
All code
========
   0:	00 00                	add    %al,(%rax)
   2:	ff 00                	incl   (%rax)
   4:	eb e8                	jmp    0xffffffffffffffee
   6:	e8 e0 7d 2a 00       	call   0x2a7deb
   b:	f3 0f 1e fa          	endbr64
   f:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  14:	55                   	push   %rbp
  15:	48 89 e5             	mov    %rsp,%rbp
  18:	53                   	push   %rbx
  19:	48 83 ec 08          	sub    $0x8,%rsp
  1d:	48 8b 87 80 00 00 00 	mov    0x80(%rdi),%rax
  24:	88 55 f4             	mov    %dl,-0xc(%rbp)
  27:	48 8b 00             	mov    (%rax),%rax
  2a:*	48 8b 98 48 02 00 00 	mov    0x248(%rax),%rbx		<-- trapping instruction
  31:	48 8b 83 90 01 00 00 	mov    0x190(%rbx),%rax
  38:	8b bb 8c 01 00 00    	mov    0x18c(%rbx),%edi
  3e:	ba                   	.byte 0xba
  3f:	01                   	.byte 0x1

Code starting with the faulting instruction
===========================================
   0:	48 8b 98 48 02 00 00 	mov    0x248(%rax),%rbx
   7:	48 8b 83 90 01 00 00 	mov    0x190(%rbx),%rax
   e:	8b bb 8c 01 00 00    	mov    0x18c(%rbx),%edi
  14:	ba                   	.byte 0xba
  15:	01                   	.byte 0x1
[   11.998003][    C9] RSP: 0018:ffffc90000507950 EFLAGS: 00010086
[   11.998003][    C9] RAX: 0000000000000000 RBX: ffffffff8279c241 RCX: ffffffff81c712c0
[   11.998003][    C9] RDX: 000000000000000a RSI: 0000000000000000 RDI: ffff888100a81180
[   11.998003][    C9] RBP: ffffc90000507960 R08: 0000000000000034 R09: 0000000000000000
[   11.998003][    C9] R10: 0000000000000001 R11: 0000000000000004 R12: 0000000000000034
[   11.998003][    C9] R13: ffffffff8279c240 R14: ffffffff8279c274 R15: 00000000ffffffff
[   11.998003][    C9] FS:  00007fcb62844740(0000) GS:ffff88817bc40000(0000) knlGS:0000000000000000
[   11.998003][    C9] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   11.998003][    C9] CR2: 0000000000000248 CR3: 0000000101d68003 CR4: 0000000000370ef0
[   11.998003][    C9] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   11.998003][    C9] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   11.998003][    C9] Call Trace:
[   11.998003][    C9]  <TASK>
[ 11.998003][ C9] ? show_regs (arch/x86/kernel/dumpstack.c:479)
[ 11.998003][ C9] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434)
[ 11.998003][ C9] ? page_fault_oops (arch/x86/mm/fault.c:714)
[ 11.998003][ C9] ? do_user_addr_fault (arch/x86/mm/fault.c:1235)
[ 11.998003][ C9] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/mm/fault.c:1488 arch/x86/mm/fault.c:1538)
[ 11.998003][ C9] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623)
[ 11.998003][ C9] ? hvc_poll_put_char (drivers/tty/hvc/hvc_console.c:879)
[ 11.998003][ C9] kgdboc_put_char (drivers/tty/serial/kgdboc.c:354)
[ 11.998003][ C9] kdb_msg_write.part.0 (kernel/debug/kdb/kdb_io.c:574)
[ 11.998003][ C9] vkdb_printf (kernel/debug/kdb/kdb_io.c:568 kernel/debug/kdb/kdb_io.c:766)
[ 11.998003][ C9] kdb_printf (kernel/debug/kdb/kdb_io.c:901)
[ 11.998003][ C9] kdb_main_loop (kernel/debug/kdb/kdb_main.c:1207 kernel/debug/kdb/kdb_main.c:1426)
[ 11.998003][ C9] ? module_event (kernel/debug/debug_core.c:880)
[ 11.998003][ C9] kdb_stub (kernel/debug/kdb/kdb_debugger.c:47 kernel/debug/kdb/kdb_debugger.c:141)
[ 11.998003][ C9] kgdb_cpu_enter (kernel/debug/debug_core.c:740)
[ 11.998003][ C9] kgdb_handle_exception (kernel/debug/debug_core.c:865)
[ 11.998003][ C9] __kgdb_notify (arch/x86/kernel/kgdb.c:548)
[ 11.998003][ C9] kgdb_notify (./arch/x86/include/asm/irqflags.h:154 arch/x86/kernel/kgdb.c:582)
[ 11.998003][ C9] notifier_call_chain (kernel/notifier.c:87)
[ 11.998003][ C9] notify_die (kernel/notifier.c:223 kernel/notifier.c:588)
[ 11.998003][ C9] exc_int3 (arch/x86/kernel/traps.c:811)
[ 11.998003][ C9] asm_exc_int3 (./arch/x86/include/asm/idtentry.h:622)
[ 11.998003][ C9] RIP: 0010:kgdb_breakpoint (kernel/debug/debug_core.c:1222)
[ 11.998003][ C9] Code: e5 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 f0 ff 05 b4 88 42 01 0f ae f8 cc <0f> ae f8 f0 ff 0d a6 88 42 01 5d c3 66 66 2e 0f 1f 84 00 00 00 00
All code
========
   0:	e5 5d                	in     $0x5d,%eax
   2:	c3                   	ret
   3:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   a:	00 00 00 00
   e:	0f 1f 40 00          	nopl   0x0(%rax)
  12:	f3 0f 1e fa          	endbr64
  16:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  1b:	55                   	push   %rbp
  1c:	48 89 e5             	mov    %rsp,%rbp
  1f:	f0 ff 05 b4 88 42 01 	lock incl 0x14288b4(%rip)        # 0x14288da
  26:	0f ae f8             	sfence
  29:	cc                   	int3
  2a:*	0f ae f8             	sfence		<-- trapping instruction
  2d:	f0 ff 0d a6 88 42 01 	lock decl 0x14288a6(%rip)        # 0x14288da
  34:	5d                   	pop    %rbp
  35:	c3                   	ret
  36:	66                   	data16
  37:	66                   	data16
  38:	2e                   	cs
  39:	0f                   	.byte 0xf
  3a:	1f                   	(bad)
  3b:	84 00                	test   %al,(%rax)
  3d:	00 00                	add    %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f ae f8             	sfence
   3:	f0 ff 0d a6 88 42 01 	lock decl 0x14288a6(%rip)        # 0x14288b0
   a:	5d                   	pop    %rbp
   b:	c3                   	ret
   c:	66                   	data16
   d:	66                   	data16
   e:	2e                   	cs
   f:	0f                   	.byte 0xf
  10:	1f                   	(bad)
  11:	84 00                	test   %al,(%rax)
  13:	00 00                	add    %al,(%rax)
	...
[   11.998003][    C9] RSP: 0018:ffffc90000507da8 EFLAGS: 00000202
[   11.998003][    C9] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffefff
[   11.998003][    C9] RDX: 0000000000000000 RSI: ffffc90000507c48 RDI: 0000000000000067
[   11.998003][    C9] RBP: ffffc90000507da8 R08: 0000000000004ffb R09: 00000000ffffefff
[   11.998003][    C9] R10: 0000000000000001 R11: ffffffff8244fd20 R12: ffffffff81c1f240
[   11.998003][    C9] R13: 0000000000000000 R14: 0000000000000067 R15: 000055ce20745a40
[ 11.998003][ C9] ? kgdb_breakpoint (kernel/debug/debug_core.c:1222)
[ 11.998003][ C9] sysrq_handle_dbg (kernel/debug/debug_core.c:987)
[ 11.998003][ C9] __handle_sysrq (./include/linux/rcupdate.h:882 drivers/tty/sysrq.c:634)
[ 11.998003][ C9] write_sysrq_trigger (drivers/tty/sysrq.c:1182)
[ 11.998003][ C9] proc_reg_write (./arch/x86/include/asm/atomic.h:85 ./include/linux/atomic/atomic-arch-fallback.h:787 ./include/linux/atomic/atomic-arch-fallback.h:1238 ./include/linux/atomic/atomic-instrumented.h:611 fs/proc/inode.c:205 fs/proc/inode.c:343)
[ 11.998003][ C9] vfs_write (fs/read_write.c:677)
[ 11.998003][ C9] ksys_write (fs/read_write.c:731)
[ 11.998003][ C9] __x64_sys_write (fs/read_write.c:739)
[ 11.998003][ C9] x64_sys_call (arch/x86/entry/syscall_64.c:36)
[ 11.998003][ C9] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 11.998003][ C9] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   11.998003][    C9] RIP: 0033:0x7fcb6293f300
[ 11.998003][ C9] Code: 40 00 48 8b 15 01 9b 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d e1 22 0e 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
All code
========
   0:	40 00 48 8b          	rex add %cl,-0x75(%rax)
   4:	15 01 9b 0d 00       	adc    $0xd9b01,%eax
   9:	f7 d8                	neg    %eax
   b:	64 89 02             	mov    %eax,%fs:(%rdx)
   e:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
  15:	eb b7                	jmp    0xffffffffffffffce
  17:	0f 1f 00             	nopl   (%rax)
  1a:	80 3d e1 22 0e 00 00 	cmpb   $0x0,0xe22e1(%rip)        # 0xe2302
  21:	74 17                	je     0x3a
  23:	b8 01 00 00 00       	mov    $0x1,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 58                	ja     0x8a
  32:	c3                   	ret
  33:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  3a:	48 83 ec 28          	sub    $0x28,%rsp
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 58                	ja     0x60
   8:	c3                   	ret
   9:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  10:	48 83 ec 28          	sub    $0x28,%rsp
  14:	48                   	rex.W
  15:	89                   	.byte 0x89
[   11.998003][    C9] RSP: 002b:00007fffbfbfcf78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[   11.998003][    C9] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fcb6293f300
[   11.998003][    C9] RDX: 0000000000000002 RSI: 000055ce20745a40 RDI: 0000000000000001
[   11.998003][    C9] RBP: 000055ce20745a40 R08: 0000000000000007 R09: 0000000000000073
[   11.998003][    C9] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
[   11.998003][    C9] R13: 00007fcb62a1a760 R14: 0000000000000002 R15: 00007fcb62a159e0
[   11.998003][    C9]  </TASK>
[   11.998003][    C9] Modules linked in:
[   11.998003][    C9] KGDB: re-enter exception: ALL breakpoints killed
[   11.998003][    C9] CR2: 0000000000000248
[   11.998003][    C9] ---[ end trace 0000000000000000 ]---
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
Testing in two circumstances:

1. back to back optical SFP+ connection between two LS1028A-QDS ports
   with the SCH-26908 riser card
2. T1042 with on-board AQR115 PHY using "OCSGMII", as per
   https://lore.kernel.org/lkml/aIuEvaSCIQdJWcZx@FUE-ALEWI-WINX/

strongly suggests that enabling in-band auto-negotiation is actually
possible when the lane baud rate is 3.125 Gbps.

It was previously thought that this would not be the case, because it
was only tested on 2500base-x links with on-board Aquantia PHYs, where
it was noticed that MII_LPA is always reported as zero, and it was
thought that this is because of the PCS.

Test case #1 above shows it is not, and the configured MII_ADVERTISE on
system A ends up in the MII_LPA on system B, when in 2500base-x mode
(IF_MODE=0).

Test case #2, which uses "SGMII" auto-negotiation (IF_MODE=3) for the
3.125 Gbps lane, is actually a misconfiguration, but it is what led to
the discovery.

There is actually an old bug in the Lynx PCS driver - it expects all
register values to contain their default out-of-reset values, as if the
PCS were initialized by the Reset Configuration Word (RCW) settings.
There are 2 cases in which this is problematic:
- if the bootloader (or previous kexec-enabled Linux) wrote a different
  IF_MODE value
- if dynamically changing the SerDes protocol from 1000base-x to
  2500base-x, e.g. by replacing the optical SFP module.

Specifically in test case #2, an accidental alignment between the
bootloader configuring the PCS to expect SGMII in-band code words, and
the AQR115 PHY actually transmitting SGMII in-band code words when
operating in the "OCSGMII" system interface protocol, led to the PCS
transmitting replicated symbols at 3.125 Gbps baud rate. This could only
have happened if the PCS saw and reacted to the SGMII code words in the
first place.

Since test #2 is invalid from a protocol perspective (there seems to be
no standard way of negotiating the data rate of 2500 Mbps with SGMII,
and the lower data rates should remain 10/100/1000), in-band auto-negotiation
for 2500base-x effectively means Clause 37 (i.e. IF_MODE=0).

Make 2500base-x be treated like 1000base-x in this regard, by removing
all prior limitations and calling lynx_pcs_config_giga().

This adds a new feature: LINK_INBAND_ENABLE and at the same time fixes
the Lynx PCS's long standing problem that the registers (specifically
IF_MODE, but others could be misconfigured as well) are not written by
the driver to the known valid values for 2500base-x.

Co-developed-by: Alexander Wilhelm <alexander.wilhelm@westermo.com>
Signed-off-by: Alexander Wilhelm <alexander.wilhelm@westermo.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20251125103507.749654-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
kbd_led_set() can sleep, and so may not be used as the brightness_set()
callback.

Otherwise using this led with a trigger leads to system hangs
accompanied by:
BUG: scheduling while atomic: acpi_fakekeyd/2588/0x00000003
CPU: 4 UID: 0 PID: 2588 Comm: acpi_fakekeyd Not tainted 6.17.9+deb14-amd64 #1 PREEMPT(lazy)  Debian 6.17.9-1
Hardware name: ASUSTeK COMPUTER INC. ASUS EXPERTBOOK B9403CVAR/B9403CVAR, BIOS B9403CVAR.311 12/24/2024
Call Trace:
 <TASK>
 [...]
 schedule_timeout+0xbd/0x100
 __down_common+0x175/0x290
 down_timeout+0x67/0x70
 acpi_os_wait_semaphore+0x57/0x90
 [...]
 asus_wmi_evaluate_method3+0x87/0x190 [asus_wmi]
 led_trigger_event+0x3f/0x60
 [...]

Fixes: 9fe44fc ("platform/x86: asus-wmi: Simplify the keyboard brightness updating process")
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Denis Benato <benato.denis96@gmail.com>
Link: https://patch.msgid.link/20251129101307.18085-3-anton@khirnov.net
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:

Chain exists of:
  &sbi->cp_rwsem --> fs_reclaim --> sb_internal#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_internal#2);
                               lock(fs_reclaim);
                               lock(sb_internal#2);
  rlock(&sbi->cp_rwsem);

 *** DEADLOCK ***

3 locks held by kswapd0/73:
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
 #2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890

stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
 f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
 f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
 f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
 f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
 f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
 f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
 evict+0x504/0x9c0 fs/inode.c:810
 f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
 evict+0x504/0x9c0 fs/inode.c:810
 dispose_list fs/inode.c:852 [inline]
 prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
 super_cache_scan+0x39b/0x4b0 fs/super.c:224
 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
 shrink_slab_memcg mm/shrinker.c:550 [inline]
 shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
 shrink_many mm/vmscan.c:5016 [inline]
 lru_gen_shrink_node mm/vmscan.c:5094 [inline]
 shrink_node+0x315d/0x3780 mm/vmscan.c:6081
 kswapd_shrink_node mm/vmscan.c:6941 [inline]
 balance_pgdat mm/vmscan.c:7124 [inline]
 kswapd+0x147c/0x2800 mm/vmscan.c:7389
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The root cause is deadlock among four locks as below:

kswapd
- fs_reclaim				--- Lock A
 - shrink_one
  - evict
   - f2fs_evict_inode
    - sb_start_intwrite			--- Lock B

- iput
 - evict
  - f2fs_evict_inode
   - sb_start_intwrite			--- Lock B
   - f2fs_truncate
    - f2fs_truncate_blocks
     - f2fs_do_truncate_blocks
      - f2fs_lock_op			--- Lock C

ioctl
- f2fs_ioc_commit_atomic_write
 - f2fs_lock_op				--- Lock C
  - __f2fs_commit_atomic_write
   - __replace_atomic_write_block
    - f2fs_get_dnode_of_data
     - __get_node_folio
      - f2fs_check_nid_range
       - f2fs_handle_error
        - f2fs_record_errors
         - f2fs_down_write		--- Lock D

open
- do_open
 - do_truncate
  - security_inode_need_killpriv
   - f2fs_getxattr
    - lookup_all_xattrs
     - f2fs_handle_error
      - f2fs_record_errors
       - f2fs_down_write		--- Lock D
        - f2fs_commit_super
         - read_mapping_folio
          - filemap_alloc_folio_noprof
           - prepare_alloc_pages
            - fs_reclaim_acquire	--- Lock A

In order to avoid such deadlock, we need to avoid grabbing sb_lock in
f2fs_handle_error(), so, let's use asynchronous method instead:
- remove f2fs_handle_error() implementation
- rename f2fs_handle_error_async() to f2fs_handle_error()
- spread f2fs_handle_error()

Fixes: 95fa90c ("f2fs: support recording errors into superblock")
Cc: stable@kernel.org
Reported-by: syzbot+14b90e1156b9f6fc1266@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/68eae49b.050a0220.ac43.0001.GAE@google.com
Reported-by: Jiaming Zhang <r772577952@gmail.com>
Closes: https://lore.kernel.org/lkml/CANypQFa-Gy9sD-N35o3PC+FystOWkNuN8pv6S75HLT0ga-Tzgw@mail.gmail.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
As syzbot reported:

F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0]
------------[ cut here ]------------
kernel BUG at fs/f2fs/extent_cache.c:678!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678
Call Trace:
 <TASK>
 f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085
 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline]
 f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737
 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030
 vfs_fallocate+0x669/0x7e0 fs/open.c:342
 ioctl_preallocate fs/ioctl.c:289 [inline]
 file_ioctl+0x611/0x780 fs/ioctl.c:-1
 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576
 __do_sys_ioctl fs/ioctl.c:595 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f07bc58eec9

In error path of f2fs_zero_range(), it may add a zero-sized extent
into extent cache, it should be avoided.

Fixes: 6e96194 ("f2fs: support in batch fzero in dnode page")
Cc: stable@kernel.org
Reported-by: syzbot+24124df3170c3638b35f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/68e5d698.050a0220.256323.0032.GAE@google.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
Bai, Shuangpeng <sjb7183@psu.edu> reported a bug as below:

Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 11441 Comm: syz.0.46 Not tainted 6.17.0 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:f2fs_all_cluster_page_ready+0x106/0x550 fs/f2fs/compress.c:857
Call Trace:
 <TASK>
 f2fs_write_cache_pages fs/f2fs/data.c:3078 [inline]
 __f2fs_write_data_pages fs/f2fs/data.c:3290 [inline]
 f2fs_write_data_pages+0x1c19/0x3600 fs/f2fs/data.c:3317
 do_writepages+0x38e/0x640 mm/page-writeback.c:2634
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 file_write_and_wait_range+0x2ba/0x3e0 mm/filemap.c:794
 f2fs_do_sync_file+0x6e6/0x1b00 fs/f2fs/file.c:294
 generic_write_sync include/linux/fs.h:3043 [inline]
 f2fs_file_write_iter+0x76e/0x2700 fs/f2fs/file.c:5259
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x7e9/0xe00 fs/read_write.c:686
 ksys_write+0x19d/0x2d0 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf7/0x470 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The bug was triggered w/ below race condition:

fsync				setattr			ioctl
- f2fs_do_sync_file
 - file_write_and_wait_range
  - f2fs_write_cache_pages
  : inode is non-compressed
  : cc.cluster_size =
    F2FS_I(inode)->i_cluster_size = 0
   - tag_pages_for_writeback
				- f2fs_setattr
				 - truncate_setsize
				 - f2fs_truncate
							- f2fs_fileattr_set
							 - f2fs_setflags_common
							  - set_compress_context
							  : F2FS_I(inode)->i_cluster_size = 4
							  : set_inode_flag(inode, FI_COMPRESSED_FILE)
   - f2fs_compressed_file
   : return true
   - f2fs_all_cluster_page_ready
   : "pgidx % cc->cluster_size" trigger dividing 0 issue

Let's change as below to fix this issue:
- introduce a new atomic type variable .writeback in structure f2fs_inode_info
to track the number of threads which calling f2fs_write_cache_pages().
- use .i_sem lock to protect .writeback update.
- check .writeback before update compression context in f2fs_setflags_common()
to avoid race w/ ->writepages.

Fixes: 4c8ff70 ("f2fs: support data compression")
Cc: stable@kernel.org
Reported-by: Bai, Shuangpeng <sjb7183@psu.edu>
Tested-by: Bai, Shuangpeng <sjb7183@psu.edu>
Closes: https://lore.kernel.org/lkml/44D8F7B3-68AD-425F-9915-65D27591F93F@psu.edu
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
As Hong Yun reported in mailing list:

loop7: detected capacity change from 0 to 131072
------------[ cut here ]------------
kmem_cache of name 'f2fs_xattr_entry-7:7' already exists
WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 kmem_cache_sanity_check mm/slab_common.c:109 [inline]
WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 __kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307
CPU: 0 UID: 0 PID: 24426 Comm: syz.7.1370 Not tainted 6.17.0-rc4 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:109 [inline]
RIP: 0010:__kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307
Call Trace:
 __kmem_cache_create include/linux/slab.h:353 [inline]
 f2fs_kmem_cache_create fs/f2fs/f2fs.h:2943 [inline]
 f2fs_init_xattr_caches+0xa5/0xe0 fs/f2fs/xattr.c:843
 f2fs_fill_super+0x1645/0x2620 fs/f2fs/super.c:4918
 get_tree_bdev_flags+0x1fb/0x260 fs/super.c:1692
 vfs_get_tree+0x43/0x140 fs/super.c:1815
 do_new_mount+0x201/0x550 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x298/0x2f0 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8e/0x3a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The bug can be reproduced w/ below scripts:
- mount /dev/vdb /mnt1
- mount /dev/vdc /mnt2
- umount /mnt1
- mounnt /dev/vdb /mnt1

The reason is if we created two slab caches, named f2fs_xattr_entry-7:3
and f2fs_xattr_entry-7:7, and they have the same slab size. Actually,
slab system will only create one slab cache core structure which has
slab name of "f2fs_xattr_entry-7:3", and two slab caches share the same
structure and cache address.

So, if we destroy f2fs_xattr_entry-7:3 cache w/ cache address, it will
decrease reference count of slab cache, rather than release slab cache
entirely, since there is one more user has referenced the cache.

Then, if we try to create slab cache w/ name "f2fs_xattr_entry-7:3" again,
slab system will find that there is existed cache which has the same name
and trigger the warning.

Let's changes to use global inline_xattr_slab instead of per-sb slab cache
for fixing.

Fixes: a999150 ("f2fs: use kmem_cache pool during inline xattr lookups")
Cc: stable@kernel.org
Reported-by: Hong Yun <yhong@link.cuhk.edu.hk>
Tested-by: Hong Yun <yhong@link.cuhk.edu.hk>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
Xfstests generic/335, generic/336 sometimes crash with the following message:

F2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1
------------[ cut here ]------------
kernel BUG at fs/f2fs/super.c:1939!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G        W           6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none)
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:f2fs_put_super+0x3b3/0x3c0
Call Trace:
 <TASK>
 generic_shutdown_super+0x7e/0x190
 kill_block_super+0x1a/0x40
 kill_f2fs_super+0x9d/0x190
 deactivate_locked_super+0x30/0xb0
 cleanup_mnt+0xba/0x150
 task_work_run+0x5c/0xa0
 exit_to_user_mode_loop+0xb7/0xc0
 do_syscall_64+0x1ae/0x1c0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
 </TASK>
---[ end trace 0000000000000000 ]---

It appears that sometimes it is possible that f2fs_put_super() is called before
all node page reads are completed.
Adding a call to f2fs_wait_on_all_pages() for F2FS_RD_NODE fixes the problem.

Cc: stable@kernel.org
Fixes: 2087258 ("f2fs: fix to drop all dirty meta/node pages during umount()")
Signed-off-by: Jan Prusakowski <jprusakowski@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
With below scripts, it will trigger panic in f2fs:

mkfs.f2fs -f /dev/vdd
mount /dev/vdd /mnt/f2fs
touch /mnt/f2fs/foo
sync
echo 111 >> /mnt/f2fs/foo
f2fs_io fsync /mnt/f2fs/foo
f2fs_io shutdown 2 /mnt/f2fs
umount /mnt/f2fs
mount -o ro,norecovery /dev/vdd /mnt/f2fs
or
mount -o ro,disable_roll_forward /dev/vdd /mnt/f2fs

F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 0
F2FS-fs (vdd): Mounted with checkpoint version = 7f5c361f
F2FS-fs (vdd): Stopped filesystem due to reason: 0
F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 1
Filesystem f2fs get_tree() didn't set fc->root, returned 1
------------[ cut here ]------------
kernel BUG at fs/super.c:1761!
Oops: invalid opcode: 0000 [#1] SMP PTI
CPU: 3 UID: 0 PID: 722 Comm: mount Not tainted 6.18.0-rc2+ torvalds#721 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:vfs_get_tree.cold+0x18/0x1a
Call Trace:
 <TASK>
 fc_mount+0x13/0xa0
 path_mount+0x34e/0xc50
 __x64_sys_mount+0x121/0x150
 do_syscall_64+0x84/0x800
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa6cc126cfe

The root cause is we missed to handle error number returned from
f2fs_recover_fsync_data() when mounting image w/ ro,norecovery or
ro,disable_roll_forward mount option, result in returning a positive
error number to vfs_get_tree(), fix it.

Cc: stable@kernel.org
Fixes: 6781eab ("f2fs: give -EINVAL for norecovery and rw mount")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
When interrupting perf stat in repeat mode with a signal the signal is
passed to the child process but the repeat doesn't terminate:
```
$ perf stat -v --null --repeat 10 sleep 1
Control descriptor is not initialized
[ perf stat: executing run #1 ... ]
[ perf stat: executing run #2 ... ]
^Csleep: Interrupt
[ perf stat: executing run #3 ... ]
[ perf stat: executing run #4 ... ]
[ perf stat: executing run #5 ... ]
[ perf stat: executing run #6 ... ]
[ perf stat: executing run #7 ... ]
[ perf stat: executing run #8 ... ]
[ perf stat: executing run #9 ... ]
[ perf stat: executing run #10 ... ]

 Performance counter stats for 'sleep 1' (10 runs):

            0.9500 +- 0.0512 seconds time elapsed  ( +-  5.39% )

0.01user 0.02system 0:09.53elapsed 0%CPU (0avgtext+0avgdata 18940maxresident)k
29944inputs+0outputs (0major+2629minor)pagefaults 0swaps
```

Terminate the repeated run and give a reasonable exit value:
```
$ perf stat -v --null --repeat 10 sleep 1
Control descriptor is not initialized
[ perf stat: executing run #1 ... ]
[ perf stat: executing run #2 ... ]
[ perf stat: executing run #3 ... ]
^Csleep: Interrupt

 Performance counter stats for 'sleep 1' (10 runs):

             0.680 +- 0.321 seconds time elapsed  ( +- 47.16% )

Command exited with non-zero status 130
0.00user 0.01system 0:02.05elapsed 0%CPU (0avgtext+0avgdata 70688maxresident)k
0inputs+0outputs (0major+5002minor)pagefaults 0swaps
```

Note, this also changes the exit value for non-repeat runs when
interrupted by a signal.

Reported-by: Ingo Molnar <mingo@kernel.org>
Closes: https://lore.kernel.org/lkml/aS5wjmbAM9ka3M2g@gmail.com/
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
At the moment - the memory allocation for fwsec-sb is created as-needed and
is released after being used. Typically this is at some point well after
driver load, which can cause runtime suspend/resume to initially work on
driver load but then later fail on a machine that has been running for long
enough with sufficiently high enough memory pressure:

  kworker/7:1: page allocation failure: order:5, mode:0xcc0(GFP_KERNEL),
  nodemask=(null),cpuset=/,mems_allowed=0
  CPU: 7 UID: 0 PID: 875159 Comm: kworker/7:1 Not tainted
  6.17.8-300.fc43.x86_64 #1 PREEMPT(lazy)
  Hardware name: SLIMBOOK Executive/Executive, BIOS N.1.10GRU06 02/02/2024
  Workqueue: pm pm_runtime_work
  Call Trace:
   <TASK>
   dump_stack_lvl+0x5d/0x80
   warn_alloc+0x163/0x190
   ? __alloc_pages_direct_compact+0x1b3/0x220
   __alloc_pages_slowpath.constprop.0+0x57a/0xb10
   __alloc_frozen_pages_noprof+0x334/0x350
   __alloc_pages_noprof+0xe/0x20
   __dma_direct_alloc_pages.isra.0+0x1eb/0x330
   dma_direct_alloc_pages+0x3c/0x190
   dma_alloc_pages+0x29/0x130
   nvkm_firmware_ctor+0x1ae/0x280 [nouveau]
   nvkm_falcon_fw_ctor+0x3e/0x60 [nouveau]
   nvkm_gsp_fwsec+0x10e/0x2c0 [nouveau]
   ? sysvec_apic_timer_interrupt+0xe/0x90
   nvkm_gsp_fwsec_sb+0x27/0x70 [nouveau]
   tu102_gsp_fini+0x65/0x110 [nouveau]
   ? ktime_get+0x3c/0xf0
   nvkm_subdev_fini+0x67/0xc0 [nouveau]
   nvkm_device_fini+0x94/0x140 [nouveau]
   nvkm_udevice_fini+0x50/0x70 [nouveau]
   nvkm_object_fini+0xb1/0x140 [nouveau]
   nvkm_object_fini+0x70/0x140 [nouveau]
   ? __pfx_pci_pm_runtime_suspend+0x10/0x10
   nouveau_do_suspend+0xe4/0x170 [nouveau]
   nouveau_pmops_runtime_suspend+0x3e/0xb0 [nouveau]
   pci_pm_runtime_suspend+0x67/0x1a0
   ? __pfx_pci_pm_runtime_suspend+0x10/0x10
   __rpm_callback+0x45/0x1f0
   ? __pfx_pci_pm_runtime_suspend+0x10/0x10
   rpm_callback+0x6d/0x80
   rpm_suspend+0xe5/0x5e0
   ? finish_task_switch.isra.0+0x99/0x2c0
   pm_runtime_work+0x98/0xb0
   process_one_work+0x18f/0x350
   worker_thread+0x25a/0x3a0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0xf9/0x240
   ? __pfx_kthread+0x10/0x10
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0xf1/0x110
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

The reason this happens is because the fwsec-sb firmware image only
supports being booted from a contiguous coherent sysmem allocation. If a
system runs into enough memory fragmentation from memory pressure, such as
what can happen on systems with low amounts of memory, this can lead to a
situation where it later becomes impossible to find space for a large
enough contiguous allocation to hold fwsec-sb. This causes us to fail to
boot the firmware image, causing the GPU to fail booting and causing the
driver to fail.

Since this firmware can't use non-contiguous allocations, the best solution
to avoid this issue is to simply allocate the memory for fwsec-sb during
initial driver-load, and reuse the memory allocation when fwsec-sb needs to
be used. We then release the memory allocations on driver unload.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 594766c ("drm/nouveau/gsp: move booter handling to GPU-specific code")
Cc: <stable@vger.kernel.org> # v6.16+
Reviewed-by: Timur Tabi <ttabi@nvidia.com>
Link: https://patch.msgid.link/20251202175918.63533-1-lyude@redhat.com
micromaomao pushed a commit that referenced this pull request Dec 20, 2025
Since commit a735831 ("drm/nouveau: vendor in drm_encoder_slave API")
nouveau appears to be broken for all dispnv04 GPUs (before NV50). Depending
on the kernel version, either having no display output and hanging in
kernel for a long time, or even oopsing in the cleanup path like:

Hardware name: PowerMac11,2 PPC970MP 0x440101 PowerMac
...
nouveau 0000:0a:00.0: drm: 0x14C5: Parsing digital output script table
BUG: Unable to handle kernel data access on read at 0x00041520
Faulting instruction address: 0xc0003d0001be0844
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=4K MMU=Hash  SMP NR_CPUS=8 NUMA PowerMac
Modules linked in: windfarm_cpufreq_clamp windfarm_smu_sensors windfarm_smu_controls windfarm_pm112 snd_aoa_codec_onyx snd_aoa_fabric_layout snd_aoa windfarm_pid jo
 apple_mfi_fastcharge rndis_host cdc_ether usbnet mii snd_aoa_i2sbus snd_aoa_soundbus snd_pcm snd_timer snd soundcore rack_meter windfarm_smu_sat windfarm_max6690_s
m75_sensor windfarm_core gpu_sched drm_gpuvm drm_exec drm_client_lib drm_ttm_helper ttm drm_display_helper drm_kms_helper drm drm_panel_orientation_quirks syscopyar
_sys_fops i2c_algo_bit backlight uio_pdrv_genirq uio uninorth_agp agpgart zram dm_mod dax ipv6 nfsv4 dns_resolver nfs lockd grace sunrpc offb cfbfillrect cfbimgblt
ont input_leds sr_mod cdrom sd_mod uas ata_generic hid_apple hid_generic usbhid hid usb_storage pata_macio sata_svw libata firewire_ohci scsi_mod firewire_core ohci
ehci_pci ehci_hcd tg3 ohci_hcd libphy usbcore usb_common nls_base
 led_class
CPU: 0 UID: 0 PID: 245 Comm: (udev-worker) Not tainted 6.14.0-09584-g7d06015d936c #7 PREEMPTLAZY
Hardware name: PowerMac11,2 PPC970MP 0x440101 PowerMac
NIP:  c0003d0001be0844 LR: c0003d0001be0830 CTR: 0000000000000000
REGS: c0000000053f70e0 TRAP: 0300   Not tainted  (6.14.0-09584-g7d06015d936c)
MSR:  9000000000009032 <SF,HV,EE,ME,IR,DR,RI>  CR: 24222220  XER: 00000000
DAR: 0000000000041520 DSISR: 40000000 IRQMASK: 0 \x0aGPR00: c0003d0001be0830 c0000000053f7380 c0003d0000911900 c000000007bc6800 \x0aGPR04: 0000000000000000 0000000000000000 c000000007bc6e70 0000000000000001 \x0aGPR08: 01f3040000000000 0000000000041520 0000000000000000 c0003d0000813958 \x0aGPR12: c000000000071a48 c000000000e28000 0000000000000020 0000000000000000 \x0aGPR16: 0000000000000000 0000000000f52630 0000000000000000 0000000000000000 \x0aGPR20: 0000000000000000 0000000000000000 0000000000000001 c0003d0000928528 \x0aGPR24: c0003d0000928598 0000000000000000 c000000007025480 c000000007025480 \x0aGPR28: c0000000010b4000 0000000000000000 c000000007bc1800 c000000007bc6800
NIP [c0003d0001be0844] nv_crtc_destroy+0x44/0xd4 [nouveau]
LR [c0003d0001be0830] nv_crtc_destroy+0x30/0xd4 [nouveau]
Call Trace:
[c0000000053f7380] [c0003d0001be0830] nv_crtc_destroy+0x30/0xd4 [nouveau] (unreliable)
[c0000000053f73c0] [c0003d00007f7bf4] drm_mode_config_cleanup+0x27c/0x30c [drm]
[c0000000053f7490] [c0003d0001bdea50] nouveau_display_create+0x1cc/0x550 [nouveau]
[c0000000053f7500] [c0003d0001bcc29c] nouveau_drm_device_init+0x1c8/0x844 [nouveau]
[c0000000053f75e0] [c0003d0001bcc9ec] nouveau_drm_probe+0xd4/0x1e0 [nouveau]
[c0000000053f7670] [c000000000557d24] local_pci_probe+0x50/0xa8
[c0000000053f76f0] [c000000000557fa8] pci_device_probe+0x22c/0x240
[c0000000053f7760] [c0000000005fff3c] really_probe+0x188/0x31c
[c0000000053f77e0] [c000000000600204] __driver_probe_device+0x134/0x13c
[c0000000053f7860] [c0000000006002c0] driver_probe_device+0x3c/0xb4
[c0000000053f78a0] [c000000000600534] __driver_attach+0x118/0x128
[c0000000053f78e0] [c0000000005fe038] bus_for_each_dev+0xa8/0xf4
[c0000000053f7950] [c0000000005ff460] driver_attach+0x2c/0x40
[c0000000053f7970] [c0000000005fea68] bus_add_driver+0x130/0x278
[c0000000053f7a00] [c00000000060117c] driver_register+0x9c/0x1a0
[c0000000053f7a80] [c00000000055623c] __pci_register_driver+0x5c/0x70
[c0000000053f7aa0] [c0003d0001c058a0] nouveau_drm_init+0x254/0x278 [nouveau]
[c0000000053f7b10] [c00000000000e9bc] do_one_initcall+0x84/0x268
[c0000000053f7bf0] [c0000000001a0ba0] do_init_module+0x70/0x2d8
[c0000000053f7c70] [c0000000001a42bc] init_module_from_file+0xb4/0x108
[c0000000053f7d50] [c0000000001a4504] sys_finit_module+0x1ac/0x478
[c0000000053f7e10] [c000000000023230] system_call_exception+0x1a4/0x20c
[c0000000053f7e50] [c00000000000c554] system_call_common+0xf4/0x258
 --- interrupt: c00 at 0xfd5f988
NIP:  000000000fd5f988 LR: 000000000ff9b148 CTR: 0000000000000000
REGS: c0000000053f7e80 TRAP: 0c00   Not tainted  (6.14.0-09584-g7d06015d936c)
MSR:  100000000000d032 <HV,EE,PR,ME,IR,DR,RI>  CR: 28222244  XER: 00000000
IRQMASK: 0 \x0aGPR00: 0000000000000161 00000000ffcdc2d0 00000000405db160 0000000000000020 \x0aGPR04: 000000000ffa2c9c 0000000000000000 000000000000001f 0000000000000045 \x0aGPR08: 0000000011a13770 0000000000000000 0000000000000000 0000000000000000 \x0aGPR12: 0000000000000000 0000000010249d8c 0000000000000020 0000000000000000 \x0aGPR16: 0000000000000000 0000000000f52630 0000000000000000 0000000000000000 \x0aGPR20: 0000000000000000 0000000000000000 0000000000000000 0000000011a11a70 \x0aGPR24: 0000000011a13580 0000000011a11950 0000000011a11a70 0000000000020000 \x0aGPR28: 000000000ffa2c9c 0000000000000000 000000000ffafc40 0000000011a11a70
NIP [000000000fd5f988] 0xfd5f988
LR [000000000ff9b148] 0xff9b148
 --- interrupt: c00
Code: f821ffc1 418200ac e93f0000 e9290038 e9291468 eba90000 48026c0d e8410018 e93f06aa 3d290001 392982a4 79291f24 <7fdd482a> 2c3e0000 41820030 7fc3f378
 ---[ end trace 0000000000000000 ]---

This is caused by the i2c encoder modules vendored into nouveau/ now
depending on the equally vendored nouveau_i2c_encoder_destroy
function. Trying to auto-load this modules hangs on nouveau
initialization until timeout, and nouveau continues without i2c video
encoders.

Fix by avoiding nouveau dependency by __always_inlining that helper
functions into those i2c video encoder modules.

Fixes: a735831 ("drm/nouveau: vendor in drm_encoder_slave API")
Signed-off-by: René Rebe <rene@exactco.de>
Reviewed-by: Lyude Paul <lyude@redhat.com>
[Lyude: fixed commit reference in description]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patch.msgid.link/20251202.164952.2216481867721531616.rene@exactco.de
micromaomao added a commit that referenced this pull request Dec 21, 2025
virtio-serial does not work with kgdboc.  I know it's an unusual use case
as one can always just use the qemu gdbserver, but still...

root@aa98fce09d67:/# echo a > /dev/hvc0
root@aa98fce09d67:/# echo a > /dev/hvc1
a
root@aa98fce09d67:/# echo g > /proc/sysrq-trigger
[   11.997004][  T146] sysrq: DEBUG
[   11.998003][    C9] BUG: kernel NULL pointer dereference, address: 0000000000000248
[   11.998003][    C9] #PF: supervisor read access in kernel mode
[   11.998003][    C9] #PF: error_code(0x0000) - not-present page
[   11.998003][    C9] PGD 0 P4D 0
[   11.998003][    C9] Oops: Oops: 0000 [#1] PREEMPT SMP
[   11.998003][    C9] CPU: 9 UID: 0 PID: 146 Comm: bash Not tainted 6.14.0-dev-00032-g11aa3e204678-dirty torvalds#122
[   11.998003][    C9] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 11.998003][ C9] RIP: 0010:hvc_poll_put_char (drivers/tty/hvc/hvc_console.c:879)
[ 11.998003][ C9] Code: 00 00 ff 00 eb e8 e8 e0 7d 2a 00 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 53 48 83 ec 08 48 8b 87 80 00 00 00 88 55 f4 48 8b 00 <48> 8b 98 48 02 00 00 48 8b 83 90 01 00 00 8b bb 8c 01 00 00 ba 01
All code
========
   0:	00 00                	add    %al,(%rax)
   2:	ff 00                	incl   (%rax)
   4:	eb e8                	jmp    0xffffffffffffffee
   6:	e8 e0 7d 2a 00       	call   0x2a7deb
   b:	f3 0f 1e fa          	endbr64
   f:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  14:	55                   	push   %rbp
  15:	48 89 e5             	mov    %rsp,%rbp
  18:	53                   	push   %rbx
  19:	48 83 ec 08          	sub    $0x8,%rsp
  1d:	48 8b 87 80 00 00 00 	mov    0x80(%rdi),%rax
  24:	88 55 f4             	mov    %dl,-0xc(%rbp)
  27:	48 8b 00             	mov    (%rax),%rax
  2a:*	48 8b 98 48 02 00 00 	mov    0x248(%rax),%rbx		<-- trapping instruction
  31:	48 8b 83 90 01 00 00 	mov    0x190(%rbx),%rax
  38:	8b bb 8c 01 00 00    	mov    0x18c(%rbx),%edi
  3e:	ba                   	.byte 0xba
  3f:	01                   	.byte 0x1

Code starting with the faulting instruction
===========================================
   0:	48 8b 98 48 02 00 00 	mov    0x248(%rax),%rbx
   7:	48 8b 83 90 01 00 00 	mov    0x190(%rbx),%rax
   e:	8b bb 8c 01 00 00    	mov    0x18c(%rbx),%edi
  14:	ba                   	.byte 0xba
  15:	01                   	.byte 0x1
[   11.998003][    C9] RSP: 0018:ffffc90000507950 EFLAGS: 00010086
[   11.998003][    C9] RAX: 0000000000000000 RBX: ffffffff8279c241 RCX: ffffffff81c712c0
[   11.998003][    C9] RDX: 000000000000000a RSI: 0000000000000000 RDI: ffff888100a81180
[   11.998003][    C9] RBP: ffffc90000507960 R08: 0000000000000034 R09: 0000000000000000
[   11.998003][    C9] R10: 0000000000000001 R11: 0000000000000004 R12: 0000000000000034
[   11.998003][    C9] R13: ffffffff8279c240 R14: ffffffff8279c274 R15: 00000000ffffffff
[   11.998003][    C9] FS:  00007fcb62844740(0000) GS:ffff88817bc40000(0000) knlGS:0000000000000000
[   11.998003][    C9] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   11.998003][    C9] CR2: 0000000000000248 CR3: 0000000101d68003 CR4: 0000000000370ef0
[   11.998003][    C9] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   11.998003][    C9] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   11.998003][    C9] Call Trace:
[   11.998003][    C9]  <TASK>
[ 11.998003][ C9] ? show_regs (arch/x86/kernel/dumpstack.c:479)
[ 11.998003][ C9] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434)
[ 11.998003][ C9] ? page_fault_oops (arch/x86/mm/fault.c:714)
[ 11.998003][ C9] ? do_user_addr_fault (arch/x86/mm/fault.c:1235)
[ 11.998003][ C9] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:37 ./arch/x86/include/asm/irqflags.h:92 arch/x86/mm/fault.c:1488 arch/x86/mm/fault.c:1538)
[ 11.998003][ C9] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623)
[ 11.998003][ C9] ? hvc_poll_put_char (drivers/tty/hvc/hvc_console.c:879)
[ 11.998003][ C9] kgdboc_put_char (drivers/tty/serial/kgdboc.c:354)
[ 11.998003][ C9] kdb_msg_write.part.0 (kernel/debug/kdb/kdb_io.c:574)
[ 11.998003][ C9] vkdb_printf (kernel/debug/kdb/kdb_io.c:568 kernel/debug/kdb/kdb_io.c:766)
[ 11.998003][ C9] kdb_printf (kernel/debug/kdb/kdb_io.c:901)
[ 11.998003][ C9] kdb_main_loop (kernel/debug/kdb/kdb_main.c:1207 kernel/debug/kdb/kdb_main.c:1426)
[ 11.998003][ C9] ? module_event (kernel/debug/debug_core.c:880)
[ 11.998003][ C9] kdb_stub (kernel/debug/kdb/kdb_debugger.c:47 kernel/debug/kdb/kdb_debugger.c:141)
[ 11.998003][ C9] kgdb_cpu_enter (kernel/debug/debug_core.c:740)
[ 11.998003][ C9] kgdb_handle_exception (kernel/debug/debug_core.c:865)
[ 11.998003][ C9] __kgdb_notify (arch/x86/kernel/kgdb.c:548)
[ 11.998003][ C9] kgdb_notify (./arch/x86/include/asm/irqflags.h:154 arch/x86/kernel/kgdb.c:582)
[ 11.998003][ C9] notifier_call_chain (kernel/notifier.c:87)
[ 11.998003][ C9] notify_die (kernel/notifier.c:223 kernel/notifier.c:588)
[ 11.998003][ C9] exc_int3 (arch/x86/kernel/traps.c:811)
[ 11.998003][ C9] asm_exc_int3 (./arch/x86/include/asm/idtentry.h:622)
[ 11.998003][ C9] RIP: 0010:kgdb_breakpoint (kernel/debug/debug_core.c:1222)
[ 11.998003][ C9] Code: e5 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 e5 f0 ff 05 b4 88 42 01 0f ae f8 cc <0f> ae f8 f0 ff 0d a6 88 42 01 5d c3 66 66 2e 0f 1f 84 00 00 00 00
All code
========
   0:	e5 5d                	in     $0x5d,%eax
   2:	c3                   	ret
   3:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
   a:	00 00 00 00
   e:	0f 1f 40 00          	nopl   0x0(%rax)
  12:	f3 0f 1e fa          	endbr64
  16:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  1b:	55                   	push   %rbp
  1c:	48 89 e5             	mov    %rsp,%rbp
  1f:	f0 ff 05 b4 88 42 01 	lock incl 0x14288b4(%rip)        # 0x14288da
  26:	0f ae f8             	sfence
  29:	cc                   	int3
  2a:*	0f ae f8             	sfence		<-- trapping instruction
  2d:	f0 ff 0d a6 88 42 01 	lock decl 0x14288a6(%rip)        # 0x14288da
  34:	5d                   	pop    %rbp
  35:	c3                   	ret
  36:	66                   	data16
  37:	66                   	data16
  38:	2e                   	cs
  39:	0f                   	.byte 0xf
  3a:	1f                   	(bad)
  3b:	84 00                	test   %al,(%rax)
  3d:	00 00                	add    %al,(%rax)
	...

Code starting with the faulting instruction
===========================================
   0:	0f ae f8             	sfence
   3:	f0 ff 0d a6 88 42 01 	lock decl 0x14288a6(%rip)        # 0x14288b0
   a:	5d                   	pop    %rbp
   b:	c3                   	ret
   c:	66                   	data16
   d:	66                   	data16
   e:	2e                   	cs
   f:	0f                   	.byte 0xf
  10:	1f                   	(bad)
  11:	84 00                	test   %al,(%rax)
  13:	00 00                	add    %al,(%rax)
	...
[   11.998003][    C9] RSP: 0018:ffffc90000507da8 EFLAGS: 00000202
[   11.998003][    C9] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffefff
[   11.998003][    C9] RDX: 0000000000000000 RSI: ffffc90000507c48 RDI: 0000000000000067
[   11.998003][    C9] RBP: ffffc90000507da8 R08: 0000000000004ffb R09: 00000000ffffefff
[   11.998003][    C9] R10: 0000000000000001 R11: ffffffff8244fd20 R12: ffffffff81c1f240
[   11.998003][    C9] R13: 0000000000000000 R14: 0000000000000067 R15: 000055ce20745a40
[ 11.998003][ C9] ? kgdb_breakpoint (kernel/debug/debug_core.c:1222)
[ 11.998003][ C9] sysrq_handle_dbg (kernel/debug/debug_core.c:987)
[ 11.998003][ C9] __handle_sysrq (./include/linux/rcupdate.h:882 drivers/tty/sysrq.c:634)
[ 11.998003][ C9] write_sysrq_trigger (drivers/tty/sysrq.c:1182)
[ 11.998003][ C9] proc_reg_write (./arch/x86/include/asm/atomic.h:85 ./include/linux/atomic/atomic-arch-fallback.h:787 ./include/linux/atomic/atomic-arch-fallback.h:1238 ./include/linux/atomic/atomic-instrumented.h:611 fs/proc/inode.c:205 fs/proc/inode.c:343)
[ 11.998003][ C9] vfs_write (fs/read_write.c:677)
[ 11.998003][ C9] ksys_write (fs/read_write.c:731)
[ 11.998003][ C9] __x64_sys_write (fs/read_write.c:739)
[ 11.998003][ C9] x64_sys_call (arch/x86/entry/syscall_64.c:36)
[ 11.998003][ C9] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 11.998003][ C9] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   11.998003][    C9] RIP: 0033:0x7fcb6293f300
[ 11.998003][ C9] Code: 40 00 48 8b 15 01 9b 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d e1 22 0e 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
All code
========
   0:	40 00 48 8b          	rex add %cl,-0x75(%rax)
   4:	15 01 9b 0d 00       	adc    $0xd9b01,%eax
   9:	f7 d8                	neg    %eax
   b:	64 89 02             	mov    %eax,%fs:(%rdx)
   e:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
  15:	eb b7                	jmp    0xffffffffffffffce
  17:	0f 1f 00             	nopl   (%rax)
  1a:	80 3d e1 22 0e 00 00 	cmpb   $0x0,0xe22e1(%rip)        # 0xe2302
  21:	74 17                	je     0x3a
  23:	b8 01 00 00 00       	mov    $0x1,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 58                	ja     0x8a
  32:	c3                   	ret
  33:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  3a:	48 83 ec 28          	sub    $0x28,%rsp
  3e:	48                   	rex.W
  3f:	89                   	.byte 0x89

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 58                	ja     0x60
   8:	c3                   	ret
   9:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  10:	48 83 ec 28          	sub    $0x28,%rsp
  14:	48                   	rex.W
  15:	89                   	.byte 0x89
[   11.998003][    C9] RSP: 002b:00007fffbfbfcf78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[   11.998003][    C9] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fcb6293f300
[   11.998003][    C9] RDX: 0000000000000002 RSI: 000055ce20745a40 RDI: 0000000000000001
[   11.998003][    C9] RBP: 000055ce20745a40 R08: 0000000000000007 R09: 0000000000000073
[   11.998003][    C9] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002
[   11.998003][    C9] R13: 00007fcb62a1a760 R14: 0000000000000002 R15: 00007fcb62a159e0
[   11.998003][    C9]  </TASK>
[   11.998003][    C9] Modules linked in:
[   11.998003][    C9] KGDB: re-enter exception: ALL breakpoints killed
[   11.998003][    C9] CR2: 0000000000000248
[   11.998003][    C9] ---[ end trace 0000000000000000 ]---

Signed-off-by: Tingmao Wang <m@maowtm.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
When crashkernel is configured with a high reservation, shrinking its
value below the low crashkernel reservation causes two issues:

1. Invalid crashkernel resource objects
2. Kernel crash if crashkernel shrinking is done twice

For example, with crashkernel=200M,high, the kernel reserves 200MB of high
memory and some default low memory (say 256MB).  The reservation appears
as:

cat /proc/iomem | grep -i crash
af000000-beffffff : Crash kernel
433000000-43f7fffff : Crash kernel

If crashkernel is then shrunk to 50MB (echo 52428800 >
/sys/kernel/kexec_crash_size), /proc/iomem still shows 256MB reserved:
af000000-beffffff : Crash kernel

Instead, it should show 50MB:
af000000-b21fffff : Crash kernel

Further shrinking crashkernel to 40MB causes a kernel crash with the
following trace (x86):

BUG: kernel NULL pointer dereference, address: 0000000000000038
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
<snip...>
Call Trace: <TASK>
? __die_body.cold+0x19/0x27
? page_fault_oops+0x15a/0x2f0
? search_module_extables+0x19/0x60
? search_bpf_extables+0x5f/0x80
? exc_page_fault+0x7e/0x180
? asm_exc_page_fault+0x26/0x30
? __release_resource+0xd/0xb0
release_resource+0x26/0x40
__crash_shrink_memory+0xe5/0x110
crash_shrink_memory+0x12a/0x190
kexec_crash_size_store+0x41/0x80
kernfs_fop_write_iter+0x141/0x1f0
vfs_write+0x294/0x460
ksys_write+0x6d/0xf0
<snip...>

This happens because __crash_shrink_memory()/kernel/crash_core.c
incorrectly updates the crashk_res resource object even when
crashk_low_res should be updated.

Fix this by ensuring the correct crashkernel resource object is updated
when shrinking crashkernel memory.

Link: https://lkml.kernel.org/r/20251101193741.289252-1-sourabhjain@linux.ibm.com
Fixes: 16c6006 ("kexec: enable kexec_crash_size to support two crash kernel regions")
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
The chain allocator field cl_bpc (blocks per cluster) is read from disk
and used in division operations without validation.  A corrupted
filesystem image with cl_bpc=0 causes a divide-by-zero crash in the
kernel:

  divide error: 0000 [#1] PREEMPT SMP KASAN
  RIP: 0010:ocfs2_bg_discontig_add_extent fs/ocfs2/suballoc.c:335 [inline]
  RIP: 0010:ocfs2_block_group_fill+0x5bd/0xa70 fs/ocfs2/suballoc.c:386
  Call Trace:
   ocfs2_block_group_alloc+0x7e9/0x1330 fs/ocfs2/suballoc.c:703
   ocfs2_reserve_suballoc_bits+0x20a6/0x4640 fs/ocfs2/suballoc.c:834
   ocfs2_reserve_new_inode+0x4f4/0xcc0 fs/ocfs2/suballoc.c:1074
   ocfs2_mknod+0x83c/0x2050 fs/ocfs2/namei.c:306

This patch adds validation in ocfs2_validate_inode_block() to ensure
cl_bpc matches the expected value calculated from the superblock's cluster
size and block size for chain allocator inodes (identified by
OCFS2_CHAIN_FL).

Moving the validation to inode validation time (rather than allocation time)
has several benefits:
- Validates once when the inode is read, rather than on every allocation
- Protects all code paths that use cl_bpc (allocation, resize, etc.)
- Follows the existing pattern of inode validation in OCFS2
- Centralizes validation logic

The validation catches both:
- Zero values that cause divide-by-zero crashes
- Non-zero but incorrect values indicating filesystem corruption or
  mismatched filesystem geometry

With this fix, mounting a corrupted filesystem produces:

  OCFS2: ERROR (device loop0): ocfs2_validate_inode_block: Inode 74
         has corrupted cl_bpc: ondisk=0 expected=16

instead of a kernel crash.

[dmantipov@yandex.ru: combine into the series and tweak the message to fit the commonly used style]
Link: https://lkml.kernel.org/r/20251030153003.1934585-2-dmantipov@yandex.ru
Link: https://lore.kernel.org/ocfs2-devel/20251026132625.12348-1-kartikey406@gmail.com/T/#u [v1]
Link: https://lore.kernel.org/all/20251027124131.10002-1-kartikey406@gmail.com/T/ [v2]
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Reported-by: syzbot+fd8af97c7227fe605d95@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fd8af97c7227fe605d95
Tested-by: syzbot+fd8af97c7227fe605d95@syzkaller.appspotmail.com
Suggested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
[BUG]
There is a report that memory allocation failed for btrfs_bio::csum
during a large read:

  b2sum: page allocation failure: order:4, mode:0x40c40(GFP_NOFS|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0
  CPU: 0 UID: 0 PID: 416120 Comm: b2sum Tainted: G        W           6.17.0 #1 NONE
  Tainted: [W]=WARN
  Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
  Call trace:
   show_stack+0x18/0x30 (C)
   dump_stack_lvl+0x5c/0x7c
   dump_stack+0x18/0x24
   warn_alloc+0xec/0x184
   __alloc_pages_slowpath.constprop.0+0x21c/0x730
   __alloc_frozen_pages_noprof+0x230/0x260
   ___kmalloc_large_node+0xd4/0xf0
   __kmalloc_noprof+0x1c8/0x260
   btrfs_lookup_bio_sums+0x214/0x278
   btrfs_submit_chunk+0xf0/0x3c0
   btrfs_submit_bbio+0x2c/0x4c
   submit_one_bio+0x50/0xac
   submit_extent_folio+0x13c/0x340
   btrfs_do_readpage+0x4b0/0x7a0
   btrfs_readahead+0x184/0x254
   read_pages+0x58/0x260
   page_cache_ra_unbounded+0x170/0x24c
   page_cache_ra_order+0x360/0x3bc
   page_cache_async_ra+0x1a4/0x1d4
   filemap_readahead.isra.0+0x44/0x74
   filemap_get_pages+0x2b4/0x3b4
   filemap_read+0xc4/0x3bc
   btrfs_file_read_iter+0x70/0x7c
   vfs_read+0x1ec/0x2c0
   ksys_read+0x4c/0xe0
   __arm64_sys_read+0x18/0x24
   el0_svc_common.constprop.0+0x5c/0x130
   do_el0_svc+0x1c/0x30
   el0_svc+0x30/0xa0
   el0t_64_sync_handler+0xa0/0xe4
   el0t_64_sync+0x198/0x19c

[CAUSE]
Btrfs needs to allocate memory for btrfs_bio::csum for large reads, so
that we can later verify the contents of the read.

However nowadays a read bio can easily go beyond BIO_MAX_VECS *
PAGE_SIZE (which is 1M for 4K page sizes), due to the multi-page bvec
that one bvec can have more than one pages, as long as the pages are
physically adjacent.

This will become more common when the large folio support is moved out
of experimental features.

In the above case, a read larger than 4MiB with SHA256 checksum (32
bytes for each 4K block) will be able to trigger a order 4 allocation.

The order 4 is larger than PAGE_ALLOC_COSTLY_ORDER (3), thus without
extra flags such allocation will not retry.

And if the system has very small amount of memory (e.g. RPI4 with low
memory spec) or VMs with small vRAM, or the memory is heavily
fragmented, such allocation will fail and cause the above warning.

[FIX]
Although btrfs is handling the memory allocation failure correctly, we
do not really need the physically contiguous memory just to restore
our checksum.

In fact btrfs_csum_one_bio() is already using kvzalloc() to reduce the
memory pressure.

So follow the step to use kvcalloc() for btrfs_bio::csum.

Reported-by: Calvin Owens <calvin@wbinvd.org>
Link: https://lore.kernel.org/linux-btrfs/20251105180054.511528-1-calvin@wbinvd.org/
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:

Chain exists of:
  &sbi->cp_rwsem --> fs_reclaim --> sb_internal#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_internal#2);
                               lock(fs_reclaim);
                               lock(sb_internal#2);
  rlock(&sbi->cp_rwsem);

 *** DEADLOCK ***

3 locks held by kswapd0/73:
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
 #2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890

stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
 f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
 f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
 f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
 f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
 f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
 f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
 evict+0x504/0x9c0 fs/inode.c:810
 f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
 evict+0x504/0x9c0 fs/inode.c:810
 dispose_list fs/inode.c:852 [inline]
 prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
 super_cache_scan+0x39b/0x4b0 fs/super.c:224
 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
 shrink_slab_memcg mm/shrinker.c:550 [inline]
 shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
 shrink_many mm/vmscan.c:5016 [inline]
 lru_gen_shrink_node mm/vmscan.c:5094 [inline]
 shrink_node+0x315d/0x3780 mm/vmscan.c:6081
 kswapd_shrink_node mm/vmscan.c:6941 [inline]
 balance_pgdat mm/vmscan.c:7124 [inline]
 kswapd+0x147c/0x2800 mm/vmscan.c:7389
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The root cause is deadlock among four locks as below:

kswapd
- fs_reclaim				--- Lock A
 - shrink_one
  - evict
   - f2fs_evict_inode
    - sb_start_intwrite			--- Lock B

- iput
 - evict
  - f2fs_evict_inode
   - sb_start_intwrite			--- Lock B
   - f2fs_truncate
    - f2fs_truncate_blocks
     - f2fs_do_truncate_blocks
      - f2fs_lock_op			--- Lock C

ioctl
- f2fs_ioc_commit_atomic_write
 - f2fs_lock_op				--- Lock C
  - __f2fs_commit_atomic_write
   - __replace_atomic_write_block
    - f2fs_get_dnode_of_data
     - __get_node_folio
      - f2fs_check_nid_range
       - f2fs_handle_error
        - f2fs_record_errors
         - f2fs_down_write		--- Lock D

open
- do_open
 - do_truncate
  - security_inode_need_killpriv
   - f2fs_getxattr
    - lookup_all_xattrs
     - f2fs_handle_error
      - f2fs_record_errors
       - f2fs_down_write		--- Lock D
        - f2fs_commit_super
         - read_mapping_folio
          - filemap_alloc_folio_noprof
           - prepare_alloc_pages
            - fs_reclaim_acquire	--- Lock A

In order to avoid such deadlock, we need to avoid grabbing sb_lock in
f2fs_handle_error(), so, let's use asynchronous method instead:
- remove f2fs_handle_error() implementation
- rename f2fs_handle_error_async() to f2fs_handle_error()
- spread f2fs_handle_error()

Fixes: 95fa90c ("f2fs: support recording errors into superblock")
Cc: stable@kernel.org
Reported-by: syzbot+14b90e1156b9f6fc1266@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/68eae49b.050a0220.ac43.0001.GAE@google.com
Reported-by: Jiaming Zhang <r772577952@gmail.com>
Closes: https://lore.kernel.org/lkml/CANypQFa-Gy9sD-N35o3PC+FystOWkNuN8pv6S75HLT0ga-Tzgw@mail.gmail.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
As syzbot reported:

F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0]
------------[ cut here ]------------
kernel BUG at fs/f2fs/extent_cache.c:678!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678
Call Trace:
 <TASK>
 f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085
 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline]
 f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737
 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030
 vfs_fallocate+0x669/0x7e0 fs/open.c:342
 ioctl_preallocate fs/ioctl.c:289 [inline]
 file_ioctl+0x611/0x780 fs/ioctl.c:-1
 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576
 __do_sys_ioctl fs/ioctl.c:595 [inline]
 __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f07bc58eec9

In error path of f2fs_zero_range(), it may add a zero-sized extent
into extent cache, it should be avoided.

Fixes: 6e96194 ("f2fs: support in batch fzero in dnode page")
Cc: stable@kernel.org
Reported-by: syzbot+24124df3170c3638b35f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-f2fs-devel/68e5d698.050a0220.256323.0032.GAE@google.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
Bai, Shuangpeng <sjb7183@psu.edu> reported a bug as below:

Oops: divide error: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 11441 Comm: syz.0.46 Not tainted 6.17.0 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:f2fs_all_cluster_page_ready+0x106/0x550 fs/f2fs/compress.c:857
Call Trace:
 <TASK>
 f2fs_write_cache_pages fs/f2fs/data.c:3078 [inline]
 __f2fs_write_data_pages fs/f2fs/data.c:3290 [inline]
 f2fs_write_data_pages+0x1c19/0x3600 fs/f2fs/data.c:3317
 do_writepages+0x38e/0x640 mm/page-writeback.c:2634
 filemap_fdatawrite_wbc mm/filemap.c:386 [inline]
 __filemap_fdatawrite_range mm/filemap.c:419 [inline]
 file_write_and_wait_range+0x2ba/0x3e0 mm/filemap.c:794
 f2fs_do_sync_file+0x6e6/0x1b00 fs/f2fs/file.c:294
 generic_write_sync include/linux/fs.h:3043 [inline]
 f2fs_file_write_iter+0x76e/0x2700 fs/f2fs/file.c:5259
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x7e9/0xe00 fs/read_write.c:686
 ksys_write+0x19d/0x2d0 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf7/0x470 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The bug was triggered w/ below race condition:

fsync				setattr			ioctl
- f2fs_do_sync_file
 - file_write_and_wait_range
  - f2fs_write_cache_pages
  : inode is non-compressed
  : cc.cluster_size =
    F2FS_I(inode)->i_cluster_size = 0
   - tag_pages_for_writeback
				- f2fs_setattr
				 - truncate_setsize
				 - f2fs_truncate
							- f2fs_fileattr_set
							 - f2fs_setflags_common
							  - set_compress_context
							  : F2FS_I(inode)->i_cluster_size = 4
							  : set_inode_flag(inode, FI_COMPRESSED_FILE)
   - f2fs_compressed_file
   : return true
   - f2fs_all_cluster_page_ready
   : "pgidx % cc->cluster_size" trigger dividing 0 issue

Let's change as below to fix this issue:
- introduce a new atomic type variable .writeback in structure f2fs_inode_info
to track the number of threads which calling f2fs_write_cache_pages().
- use .i_sem lock to protect .writeback update.
- check .writeback before update compression context in f2fs_setflags_common()
to avoid race w/ ->writepages.

Fixes: 4c8ff70 ("f2fs: support data compression")
Cc: stable@kernel.org
Reported-by: Bai, Shuangpeng <sjb7183@psu.edu>
Tested-by: Bai, Shuangpeng <sjb7183@psu.edu>
Closes: https://lore.kernel.org/lkml/44D8F7B3-68AD-425F-9915-65D27591F93F@psu.edu
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
As Hong Yun reported in mailing list:

loop7: detected capacity change from 0 to 131072
------------[ cut here ]------------
kmem_cache of name 'f2fs_xattr_entry-7:7' already exists
WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 kmem_cache_sanity_check mm/slab_common.c:109 [inline]
WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 __kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307
CPU: 0 UID: 0 PID: 24426 Comm: syz.7.1370 Not tainted 6.17.0-rc4 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:109 [inline]
RIP: 0010:__kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307
Call Trace:
 __kmem_cache_create include/linux/slab.h:353 [inline]
 f2fs_kmem_cache_create fs/f2fs/f2fs.h:2943 [inline]
 f2fs_init_xattr_caches+0xa5/0xe0 fs/f2fs/xattr.c:843
 f2fs_fill_super+0x1645/0x2620 fs/f2fs/super.c:4918
 get_tree_bdev_flags+0x1fb/0x260 fs/super.c:1692
 vfs_get_tree+0x43/0x140 fs/super.c:1815
 do_new_mount+0x201/0x550 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x298/0x2f0 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8e/0x3a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The bug can be reproduced w/ below scripts:
- mount /dev/vdb /mnt1
- mount /dev/vdc /mnt2
- umount /mnt1
- mounnt /dev/vdb /mnt1

The reason is if we created two slab caches, named f2fs_xattr_entry-7:3
and f2fs_xattr_entry-7:7, and they have the same slab size. Actually,
slab system will only create one slab cache core structure which has
slab name of "f2fs_xattr_entry-7:3", and two slab caches share the same
structure and cache address.

So, if we destroy f2fs_xattr_entry-7:3 cache w/ cache address, it will
decrease reference count of slab cache, rather than release slab cache
entirely, since there is one more user has referenced the cache.

Then, if we try to create slab cache w/ name "f2fs_xattr_entry-7:3" again,
slab system will find that there is existed cache which has the same name
and trigger the warning.

Let's changes to use global inline_xattr_slab instead of per-sb slab cache
for fixing.

Fixes: a999150 ("f2fs: use kmem_cache pool during inline xattr lookups")
Cc: stable@kernel.org
Reported-by: Hong Yun <yhong@link.cuhk.edu.hk>
Tested-by: Hong Yun <yhong@link.cuhk.edu.hk>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
Xfstests generic/335, generic/336 sometimes crash with the following message:

F2FS-fs (dm-0): detect filesystem reference count leak during umount, type: 9, count: 1
------------[ cut here ]------------
kernel BUG at fs/f2fs/super.c:1939!
Oops: invalid opcode: 0000 [#1] SMP NOPTI
CPU: 1 UID: 0 PID: 609351 Comm: umount Tainted: G        W           6.17.0-rc5-xfstests-g9dd1835ecda5 #1 PREEMPT(none)
Tainted: [W]=WARN
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:f2fs_put_super+0x3b3/0x3c0
Call Trace:
 <TASK>
 generic_shutdown_super+0x7e/0x190
 kill_block_super+0x1a/0x40
 kill_f2fs_super+0x9d/0x190
 deactivate_locked_super+0x30/0xb0
 cleanup_mnt+0xba/0x150
 task_work_run+0x5c/0xa0
 exit_to_user_mode_loop+0xb7/0xc0
 do_syscall_64+0x1ae/0x1c0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
 </TASK>
---[ end trace 0000000000000000 ]---

It appears that sometimes it is possible that f2fs_put_super() is called before
all node page reads are completed.
Adding a call to f2fs_wait_on_all_pages() for F2FS_RD_NODE fixes the problem.

Cc: stable@kernel.org
Fixes: 2087258 ("f2fs: fix to drop all dirty meta/node pages during umount()")
Signed-off-by: Jan Prusakowski <jprusakowski@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
With below scripts, it will trigger panic in f2fs:

mkfs.f2fs -f /dev/vdd
mount /dev/vdd /mnt/f2fs
touch /mnt/f2fs/foo
sync
echo 111 >> /mnt/f2fs/foo
f2fs_io fsync /mnt/f2fs/foo
f2fs_io shutdown 2 /mnt/f2fs
umount /mnt/f2fs
mount -o ro,norecovery /dev/vdd /mnt/f2fs
or
mount -o ro,disable_roll_forward /dev/vdd /mnt/f2fs

F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 0
F2FS-fs (vdd): Mounted with checkpoint version = 7f5c361f
F2FS-fs (vdd): Stopped filesystem due to reason: 0
F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 1
Filesystem f2fs get_tree() didn't set fc->root, returned 1
------------[ cut here ]------------
kernel BUG at fs/super.c:1761!
Oops: invalid opcode: 0000 [#1] SMP PTI
CPU: 3 UID: 0 PID: 722 Comm: mount Not tainted 6.18.0-rc2+ torvalds#721 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:vfs_get_tree.cold+0x18/0x1a
Call Trace:
 <TASK>
 fc_mount+0x13/0xa0
 path_mount+0x34e/0xc50
 __x64_sys_mount+0x121/0x150
 do_syscall_64+0x84/0x800
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fa6cc126cfe

The root cause is we missed to handle error number returned from
f2fs_recover_fsync_data() when mounting image w/ ro,norecovery or
ro,disable_roll_forward mount option, result in returning a positive
error number to vfs_get_tree(), fix it.

Cc: stable@kernel.org
Fixes: 6781eab ("f2fs: give -EINVAL for norecovery and rw mount")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
micromaomao pushed a commit that referenced this pull request Dec 21, 2025
The CMT device can be used as both a clocksource and a clockevent
provider. The driver tries to be smart and power itself on and off, as
well as enabling and disabling its clock when it's not in operation.
This behavior is slightly altered if the CMT is used as an early
platform device in which case the device is left powered on after probe,
but the clock is still enabled and disabled at runtime.

This has worked for a long time, but recent improvements in PREEMPT_RT
and PROVE_LOCKING have highlighted an issue. As the CMT registers itself
as a clockevent provider, clockevents_register_device(), it needs to use
raw spinlocks internally as this is the context of which the clockevent
framework interacts with the CMT driver. However in the context of
holding a raw spinlock the CMT driver can't really manage its power
state or clock with calls to pm_runtime_*() and clk_*() as these calls
end up in other platform drivers using regular spinlocks to control
power and clocks.

This mix of spinlock contexts trips a lockdep warning.

    =============================
    [ BUG: Invalid wait context ]
    6.17.0-rc3-arm64-renesas-03071-gb3c4f4122b28-dirty torvalds#21 Not tainted
    -----------------------------
    swapper/1/0 is trying to lock:
    ffff00000898d180 (&dev->power.lock){-...}-{3:3}, at: __pm_runtime_resume+0x38/0x88
    ccree e6601000.crypto: ARM CryptoCell 630P Driver: HW version 0xAF400001/0xDCC63000, Driver version 5.0
    other info that might help us debug this:
    ccree e6601000.crypto: ARM ccree device initialized
    context-{5:5}
    2 locks held by swapper/1/0:
     #0: ffff80008173c298 (tick_broadcast_lock){-...}-{2:2}, at: __tick_broadcast_oneshot_control+0xa4/0x3a8
     #1: ffff0000089a5858 (&ch->lock){....}-{2:2}
    usbcore: registered new interface driver usbhid
    , at: sh_cmt_start+0x30/0x364
    stack backtrace:
    CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.17.0-rc3-arm64-renesas-03071-gb3c4f4122b28-dirty torvalds#21 PREEMPT
    Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT)
    Call trace:
     show_stack+0x14/0x1c (C)
     dump_stack_lvl+0x6c/0x90
     dump_stack+0x14/0x1c
     __lock_acquire+0x904/0x1584
     lock_acquire+0x220/0x34c
     _raw_spin_lock_irqsave+0x58/0x80
     __pm_runtime_resume+0x38/0x88
     sh_cmt_start+0x54/0x364
     sh_cmt_clock_event_set_oneshot+0x64/0xb8
     clockevents_switch_state+0xfc/0x13c
     tick_broadcast_set_event+0x30/0xa4
     __tick_broadcast_oneshot_control+0x1e0/0x3a8
     tick_broadcast_oneshot_control+0x30/0x40
     cpuidle_enter_state+0x40c/0x680
     cpuidle_enter+0x30/0x40
     do_idle+0x1f4/0x26c
     cpu_startup_entry+0x34/0x40
     secondary_start_kernel+0x11c/0x13c
     __secondary_switched+0x74/0x78

For non-PREEMPT_RT builds this is not really an issue, but for
PREEMPT_RT builds where normal spinlocks can sleep this might be an
issue. Be cautious and always leave the power and clock running after
probe.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20251016182022.1837417-1-niklas.soderlund+renesas@ragnatech.se
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