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| author | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:27:25 -0800 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:27:36 -0800 |
| commit | 231c56760c1e2ded21ad96bbb860b1f08c556c7a (patch) | |
| tree | 4aca6b1947a0188731cbf37e27b307cc8603b1ef /sysdeps/x86_64/multiarch/memcpy-ssse3-back.S | |
| parent | b304fc201d2f6baf52ea790df8643e99772243cd (diff) | |
| download | glibc-231c56760c1e2ded21ad96bbb860b1f08c556c7a.tar.gz glibc-231c56760c1e2ded21ad96bbb860b1f08c556c7a.tar.xz glibc-231c56760c1e2ded21ad96bbb860b1f08c556c7a.zip | |
x86-64 memcpy: 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 memcpy 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/memcpy-ssse3-back.S: Use RDX_LP for length. Clear the upper 32 bits of RDX register. * sysdeps/x86_64/multiarch/memcpy-ssse3.S: Likewise. * sysdeps/x86_64/multiarch/memmove-avx512-no-vzeroupper.S: Likewise. * sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memcpy. tst-size_t-wmemchr. * sysdeps/x86_64/x32/tst-size_t-memcpy.c: New file.
Diffstat (limited to 'sysdeps/x86_64/multiarch/memcpy-ssse3-back.S')
| -rw-r--r-- | sysdeps/x86_64/multiarch/memcpy-ssse3-back.S | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S b/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S index bcfb21e75a..b9188cbcfb 100644 --- a/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S +++ b/sysdeps/x86_64/multiarch/memcpy-ssse3-back.S @@ -45,28 +45,33 @@ .section .text.ssse3,"ax",@progbits #if !defined USE_AS_MEMPCPY && !defined USE_AS_MEMMOVE ENTRY (MEMPCPY_CHK) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMPCPY_CHK) ENTRY (MEMPCPY) - movq %rdi, %rax - addq %rdx, %rax + mov %RDI_LP, %RAX_LP + add %RDX_LP, %RAX_LP jmp L(start) END (MEMPCPY) #endif #if !defined USE_AS_BCOPY ENTRY (MEMCPY_CHK) - cmpq %rdx, %rcx + cmp %RDX_LP, %RCX_LP jb HIDDEN_JUMPTARGET (__chk_fail) END (MEMCPY_CHK) #endif ENTRY (MEMCPY) - mov %rdi, %rax + mov %RDI_LP, %RAX_LP #ifdef USE_AS_MEMPCPY - add %rdx, %rax + add %RDX_LP, %RAX_LP +#endif + +#ifdef __ILP32__ + /* Clear the upper 32 bits. */ + mov %edx, %edx #endif #ifdef USE_AS_MEMMOVE |