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| author | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:29:58 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:30:12 -0800 |
| commit | ecd8b842cf37ea112e59cd9085ff1f1b6e208ae0 (patch) | |
| tree | 66fccd2376120240e84e0e41a5cadc21ec4e077d /sysdeps/x86_64/memrchr.S | |
| parent | 231c56760c1e2ded21ad96bbb860b1f08c556c7a (diff) | |
| download | glibc-ecd8b842cf37ea112e59cd9085ff1f1b6e208ae0.tar.gz glibc-ecd8b842cf37ea112e59cd9085ff1f1b6e208ae0.tar.xz glibc-ecd8b842cf37ea112e59cd9085ff1f1b6e208ae0.zip | |
x86-64 memrchr: Properly handle the length parameter [BZ# 24097]
On x32, the size_t parameter may be passed in the lower 32 bits of a 64-bit register with the non-zero upper 32 bits. The string/memory functions written in assembly can only use the lower 32 bits of a 64-bit register as length or must clear the upper 32 bits before using the full 64-bit register for length. This pach fixes memrchr for x32. Tested on x86-64 and x32. On x86-64, libc.so is the same with and withou the fix. [BZ# 24097] CVE-2019-6488 * sysdeps/x86_64/memrchr.S: Use RDX_LP for length. * sysdeps/x86_64/multiarch/memrchr-avx2.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memrchr. * sysdeps/x86_64/x32/tst-size_t-memrchr.c: New file.
Diffstat (limited to 'sysdeps/x86_64/memrchr.S')
| -rw-r--r-- | sysdeps/x86_64/memrchr.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/x86_64/memrchr.S b/sysdeps/x86_64/memrchr.S index 0483b1d2e9..131796aefc 100644 --- a/sysdeps/x86_64/memrchr.S +++ b/sysdeps/x86_64/memrchr.S @@ -24,13 +24,13 @@ ENTRY (__memrchr) movd %esi, %xmm1 - sub $16, %rdx + sub $16, %RDX_LP jbe L(length_less16) punpcklbw %xmm1, %xmm1 punpcklbw %xmm1, %xmm1 - add %rdx, %rdi + add %RDX_LP, %RDI_LP pshufd $0, %xmm1, %xmm1 movdqu (%rdi), %xmm0 |