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| author | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:35:18 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:35:34 -0800 |
| commit | c7c54f65b080affb87a1513dee449c8ad6143c8b (patch) | |
| tree | 7843555220fda4dbbe023b2035a8de081810128a /sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S | |
| parent | ee915088a0231cd421054dbd8abab7aadf331153 (diff) | |
| download | glibc-c7c54f65b080affb87a1513dee449c8ad6143c8b.tar.gz glibc-c7c54f65b080affb87a1513dee449c8ad6143c8b.tar.xz glibc-c7c54f65b080affb87a1513dee449c8ad6143c8b.zip | |
x86-64 strncpy: 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 strncpy 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/strcpy-avx2.S: Use RDX_LP for length. * sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S: Likewise. * sysdeps/x86_64/multiarch/strcpy-ssse3.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-strncpy. * sysdeps/x86_64/x32/tst-size_t-strncpy.c: New file.
Diffstat (limited to 'sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S b/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S index b7c79976ea..0d6914e113 100644 --- a/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S +++ b/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S @@ -40,8 +40,8 @@ .text ENTRY (STRCPY) # ifdef USE_AS_STRNCPY - mov %rdx, %r8 - test %r8, %r8 + mov %RDX_LP, %R8_LP + test %R8_LP, %R8_LP jz L(ExitZero) # endif mov %rsi, %rcx |