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| author | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:33:52 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:34:04 -0800 |
| commit | ee915088a0231cd421054dbd8abab7aadf331153 (patch) | |
| tree | bda23563b2fe03f78a95219922c8fecf6a86f9df /sysdeps/x86_64/strcmp.S | |
| parent | 82d0b4a4d76db554eb6757acb790fcea30b19965 (diff) | |
| download | glibc-ee915088a0231cd421054dbd8abab7aadf331153.tar.gz glibc-ee915088a0231cd421054dbd8abab7aadf331153.tar.xz glibc-ee915088a0231cd421054dbd8abab7aadf331153.zip | |
x86-64 strncmp family: 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 the strncmp family 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/multiarch/strcmp-avx2.S: Use RDX_LP for length. * sysdeps/x86_64/multiarch/strcmp-sse42.S: Likewise. * sysdeps/x86_64/strcmp.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-strncasecmp, tst-size_t-strncmp and tst-size_t-wcsncmp. * sysdeps/x86_64/x32/tst-size_t-strncasecmp.c: New file. * sysdeps/x86_64/x32/tst-size_t-strncmp.c: Likewise. * sysdeps/x86_64/x32/tst-size_t-wcsncmp.c: Likewise.
Diffstat (limited to 'sysdeps/x86_64/strcmp.S')
| -rw-r--r-- | sysdeps/x86_64/strcmp.S | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/sysdeps/x86_64/strcmp.S b/sysdeps/x86_64/strcmp.S index 55445148d5..f95463155a 100644 --- a/sysdeps/x86_64/strcmp.S +++ b/sysdeps/x86_64/strcmp.S @@ -135,11 +135,11 @@ ENTRY (STRCMP) * This implementation uses SSE to compare up to 16 bytes at a time. */ #if defined USE_AS_STRNCMP || defined USE_AS_STRNCASECMP_L - test %rdx, %rdx + test %RDX_LP, %RDX_LP je LABEL(strcmp_exitz) - cmp $1, %rdx + cmp $1, %RDX_LP je LABEL(Byte0) - mov %rdx, %r11 + mov %RDX_LP, %R11_LP #endif mov %esi, %ecx mov %edi, %eax |