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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/multiarch | |
| parent | 82d0b4a4d76db554eb6757acb790fcea30b19965 (diff) | |
| download | glibc-ee915088a0231cd421054dbd8abab7aadf331153.zip glibc-ee915088a0231cd421054dbd8abab7aadf331153.tar.gz glibc-ee915088a0231cd421054dbd8abab7aadf331153.tar.bz2 | |
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/multiarch')
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcmp-avx2.S | 6 | ||||
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcmp-sse42.S | 6 |
2 files changed, 6 insertions, 6 deletions
diff --git a/sysdeps/x86_64/multiarch/strcmp-avx2.S b/sysdeps/x86_64/multiarch/strcmp-avx2.S index 0c27f90..b32a5e3 100644 --- a/sysdeps/x86_64/multiarch/strcmp-avx2.S +++ b/sysdeps/x86_64/multiarch/strcmp-avx2.S @@ -79,15 +79,15 @@ ENTRY (STRCMP) # ifdef USE_AS_STRNCMP /* Check for simple cases (0 or 1) in offset. */ - cmp $1, %rdx + cmp $1, %RDX_LP je L(char0) jb L(zero) # ifdef USE_AS_WCSCMP /* Convert units: from wide to byte char. */ - shl $2, %rdx + shl $2, %RDX_LP # endif /* Register %r11 tracks the maximum offset. */ - movq %rdx, %r11 + mov %RDX_LP, %R11_LP # endif movl %edi, %eax xorl %edx, %edx diff --git a/sysdeps/x86_64/multiarch/strcmp-sse42.S b/sysdeps/x86_64/multiarch/strcmp-sse42.S index 2f4b34a..73bbe5c 100644 --- a/sysdeps/x86_64/multiarch/strcmp-sse42.S +++ b/sysdeps/x86_64/multiarch/strcmp-sse42.S @@ -156,11 +156,11 @@ STRCMP_SSE42: #endif #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 |