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author | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:25:56 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2019-01-21 11:26:07 -0800 |
commit | b304fc201d2f6baf52ea790df8643e99772243cd (patch) | |
tree | 502227813e790ba46c8f6e4ee826cb3f36ffb9bb /sysdeps/x86_64/x32/tst-size_t-wmemcmp.c | |
parent | 97700a34f36721b11a754cf37a1cc40695ece1fd (diff) | |
download | glibc-b304fc201d2f6baf52ea790df8643e99772243cd.tar.gz glibc-b304fc201d2f6baf52ea790df8643e99772243cd.tar.xz glibc-b304fc201d2f6baf52ea790df8643e99772243cd.zip |
x86-64 memcmp/wmemcmp: 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 memcmp/wmemcmp 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/memcmp-avx2-movbe.S: Use RDX_LP for length. Clear the upper 32 bits of RDX register. * sysdeps/x86_64/multiarch/memcmp-sse4.S: Likewise. * sysdeps/x86_64/multiarch/memcmp-ssse3.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memcmp and tst-size_t-wmemcmp. * sysdeps/x86_64/x32/tst-size_t-memcmp.c: New file. * sysdeps/x86_64/x32/tst-size_t-wmemcmp.c: Likewise.
Diffstat (limited to 'sysdeps/x86_64/x32/tst-size_t-wmemcmp.c')
-rw-r--r-- | sysdeps/x86_64/x32/tst-size_t-wmemcmp.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/sysdeps/x86_64/x32/tst-size_t-wmemcmp.c b/sysdeps/x86_64/x32/tst-size_t-wmemcmp.c new file mode 100644 index 0000000000..e8b5ffd0d5 --- /dev/null +++ b/sysdeps/x86_64/x32/tst-size_t-wmemcmp.c @@ -0,0 +1,20 @@ +/* Test wmemcmp with size_t in the lower 32 bits of 64-bit register. + Copyright (C) 2019 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#define WIDE 1 +#include "tst-size_t-memcmp.c" |