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Fix user data alignment in MEMBLOCK #1471

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Merged
aquynh merged 2 commits into from
May 9, 2019
Merged

Fix user data alignment in MEMBLOCK #1471

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094cd20
Fix user data alignment in MEMBLOCK
mbikovitsky May 5, 2019
16cdf95
Fix user data alignment in CS_WINKERNEL_MEMBLOCK
mbikovitsky May 8, 2019
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1 change: 1 addition & 0 deletions contrib/windows_kernel/libc.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@ struct MEMBLOCK
size_t size;
#pragma warning(push)
#pragma warning (disable : 4200)
__declspec(align(MEMORY_ALLOCATION_ALIGNMENT))
char data[0];
#pragma warning(pop)
};
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6 changes: 3 additions & 3 deletions windows/winkernel_mm.c
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Expand Up @@ -12,9 +12,9 @@ static const ULONG CS_WINKERNEL_POOL_TAG = 'kwsC';
// A structure to implement realloc()
typedef struct _CS_WINKERNEL_MEMBLOCK {
size_t size; // A number of bytes allocated
char data[1]; // An address returned to a caller
__declspec(align(MEMORY_ALLOCATION_ALIGNMENT))
char data[ANYSIZE_ARRAY]; // An address returned to a caller
} CS_WINKERNEL_MEMBLOCK;
C_ASSERT(sizeof(CS_WINKERNEL_MEMBLOCK) == sizeof(void *) * 2);


// free()
Expand All @@ -39,7 +39,7 @@ void * CAPSTONE_API cs_winkernel_malloc(size_t size)
// A specially crafted size value can trigger the overflow.
// If the sum in a value that overflows or underflows the capacity of the type,
// the function returns NULL.
if (!NT_SUCCESS(RtlSizeTAdd(size, sizeof(CS_WINKERNEL_MEMBLOCK), &number_of_bytes))) {
if (!NT_SUCCESS(RtlSizeTAdd(size, FIELD_OFFSET(CS_WINKERNEL_MEMBLOCK, data), &number_of_bytes))) {
return NULL;
}
block = (CS_WINKERNEL_MEMBLOCK *)ExAllocatePoolWithTag(
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