shadps4-emu/ext-cryptopp
1
0
Fork 0
mirror of https://github.com/shadps4-emu/ext-cryptopp.git synced 2024-11-23 09:59:42 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix buffer underrun in FixedSizeAllocatorWithCleanup when CRYPTOPP_BOOL_ALIGN16==0 (GH #982)

Browse Source
This commit is contained in:
Jeffrey Walton 2020-12-24 14:20:23 -05:00
parent 5537d998a1
commit 60aa3e7fe9
No known key found for this signature in database
GPG Key ID: B36AB348921B1838
1 changed files with 21 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
secblock.h
View File

@ -517,23 +517,34 @@ private:
// The library is OK but users may hit it. So we need to guard
// for a large T, and that is what PAD achieves.
T* GetAlignedArray() {
T* p_array = reinterpret_cast<T*>(static_cast<void*>((reinterpret_cast<byte*>(m_array)) + (0-reinterpret_cast<size_t>(m_array))%16));
// m_array is aligned on 8 byte boundaries due to
// CRYPTOPP_ALIGN_DATA(8). If m_array%16 is 0, then
// the buffer is 16-byte aligned and nothing needs
// to be done. if m_array%16 is 8, then the buffer
// is not 16-byte aligned and we need to add 8.
CRYPTOPP_ASSERT(IsAlignedOn(m_array, 8));
int off = reinterpret_cast<uintptr_t>(m_array) % 8;
byte* ptr = reinterpret_cast<byte*>(m_array) + off;
// Verify the 16-byte alignment
CRYPTOPP_ASSERT(IsAlignedOn(p_array, 16));
CRYPTOPP_ASSERT(IsAlignedOn(ptr, 16));
// Verify allocated array with pad is large enough.
CRYPTOPP_ASSERT(p_array+S*sizeof(T) <= m_array+(S+PAD));
return p_array;
CRYPTOPP_ASSERT(
reinterpret_cast<uintptr_t>(ptr+S*sizeof(T)) <=
reinterpret_cast<uintptr_t>(m_array+(S+PAD))
);
// void* to silence Clang warnings
return reinterpret_cast<T*>(
static_cast<void*>(ptr)
);
}
# if defined(_AIX)
// PAD is elements, not bytes, and rounded up to ensure no overflow.
enum { Q = sizeof(T), PAD = (Q >= 16) ? 1 : (Q >= 8) ? 2 : (Q >= 4) ? 4 : (Q >= 2) ? 8 : 16 };
CRYPTOPP_ALIGN_DATA(8) T m_array[S+PAD];
# else
// PAD is elements, not bytes, and rounded up to ensure no overflow.
enum { Q = sizeof(T), PAD = (Q >= 8) ? 1 : (Q >= 4) ? 2 : (Q >= 2) ? 4 : 8 };
// enum { Q = sizeof(T), PAD = (Q >= 16) ? 1 : (Q >= 8) ? 2 : (Q >= 4) ? 4 : (Q >= 2) ? 8 : 16 };
CRYPTOPP_ALIGN_DATA(8) T m_array[S+PAD];
# endif
#else