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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.
15 lines
445 B
Makefile
15 lines
445 B
Makefile
ifeq ($(subdir),math)
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# Since x32 returns 32-bit long int and 64-bit long long int in the
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# same 64-bit register, we make the 32b-bit lround an alias of the
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# 64-bit llround. Add -fno-builtin-lround to silence the compiler.
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CFLAGS-s_llround.c += -fno-builtin-lround
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endif
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ifeq ($(subdir),string)
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tests += tst-size_t-memchr tst-size_t-memcmp tst-size_t-memcpy
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endif
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ifeq ($(subdir),wcsmbs)
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tests += tst-size_t-wmemchr tst-size_t-wmemcmp
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endif
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