Root: do not error out with EEXIST for racing Root::mkdir_all()s#131
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It would be nice if there was an EUNSAFE we could use, but alas there is no such errno, so we will have to reuse the same errno that openat2() uses when a walk ends up outside of the rootfs. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
There is no reason to use the resolver to look a path component under a directory we have a handle to already. The O_NOFOLLOW behaviour was also somewhat hidden behind the way the resolver API works. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
If two programs are doing Root::mkdir_all, the previous logic would return an error if a directory already existed once we got into the "mkdir" portion of the creation. Since we already have to accept that an attacker can swap the inode with a different directory, returning -EEXIST from mkdirat(2) just causes spurious errors. All we care about is that we open a directory. Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
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If two programs are doing Root::mkdir_all, the previous logic would
return an error if a directory already existed once we got into the
"mkdir" portion of the creation.
Since we already have to accept that an attacker can swap the inode with
a different directory, returning -EEXIST from mkdirat(2) just causes
spurious errors. All we care about is that we open a directory.
Fixes #128
Signed-off-by: Aleksa Sarai cyphar@cyphar.com