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authorH.J. Lu <hjl.tools@gmail.com>2019-01-21 11:32:24 -0800
committerH.J. Lu <hjl.tools@gmail.com>2019-01-21 11:32:37 -0800
commit82d0b4a4d76db554eb6757acb790fcea30b19965 (patch)
treea3cb4225e0d8370936489c41be107825ba20a301 /sysdeps/x86_64/multiarch/strcmp-avx2.S
parentecd8b842cf37ea112e59cd9085ff1f1b6e208ae0 (diff)
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x86-64 memset/wmemset: 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 memset/wmemset 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/memset-avx512-no-vzeroupper.S: Use
	RDX_LP for length.  Clear the upper 32 bits of RDX register.
	* sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: Likewise.
	* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-wmemset.
	* sysdeps/x86_64/x32/tst-size_t-memset.c: New file.
	* sysdeps/x86_64/x32/tst-size_t-wmemset.c: Likewise.
Diffstat (limited to 'sysdeps/x86_64/multiarch/strcmp-avx2.S')
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