| Message ID | 1456348432-18818-2-git-send-email-lersek@redhat.com |
|---|---|
| State | Superseded |
| Headers | show |
diff --git a/CryptoPkg/Library/BaseCryptLib/SysCall/BaseMemAllocation.c b/CryptoPkg/Library/BaseCryptLib/SysCall/BaseMemAllocation.c index 544f07215b8f..964545f143cc 100644 --- a/CryptoPkg/Library/BaseCryptLib/SysCall/BaseMemAllocation.c +++ b/CryptoPkg/Library/BaseCryptLib/SysCall/BaseMemAllocation.c @@ -38,5 +38,11 @@ void *realloc (void *ptr, size_t size) /* De-allocates or frees a memory block */ void free (void *ptr) { - FreePool (ptr); + // + // In Standard C, free() handles a null pointer argument transparently. This + // is not true of FreePool() below, so protect it. + // + if (ptr != NULL) { + FreePool (ptr); + } }
The ISO C standard says about free(), If ptr is a null pointer, no action occurs. This is not true of the FreePool() interface of the MemoryAllocationLib class: Buffer must have been allocated on a previous call to the pool allocation services of the Memory Allocation Library. [...] If Buffer was not allocated with a pool allocation function in the Memory Allocation Library, then ASSERT(). Therefore we must not forward the argument of free() to FreePool() without checking. This bug can be triggered by upstream OpenSSL commit 8e704858f219 ("RT3955: Reduce some stack usage"), for example. Cc: David Woodhouse <dwmw2@infradead.org> Cc: Qin Long <qin.long@intel.com> Cc: Ting Ye <ting.ye@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <lersek@redhat.com> --- CryptoPkg/Library/BaseCryptLib/SysCall/BaseMemAllocation.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) -- 1.8.3.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel