From 97700a34f36721b11a754cf37a1cc40695ece1fd Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Mon, 21 Jan 2019 11:23:59 -0800 Subject: x86-64 memchr/wmemchr: 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 memchr/wmemchr 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/memchr.S: Use RDX_LP for length. Clear the upper 32 bits of RDX register. * sysdeps/x86_64/multiarch/memchr-avx2.S: Likewise. * sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-memchr and tst-size_t-wmemchr. * sysdeps/x86_64/x32/test-size_t.h: New file. * sysdeps/x86_64/x32/tst-size_t-memchr.c: Likewise. * sysdeps/x86_64/x32/tst-size_t-wmemchr.c: Likewise. --- sysdeps/x86_64/x32/tst-size_t-wmemchr.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 sysdeps/x86_64/x32/tst-size_t-wmemchr.c (limited to 'sysdeps/x86_64/x32/tst-size_t-wmemchr.c') diff --git a/sysdeps/x86_64/x32/tst-size_t-wmemchr.c b/sysdeps/x86_64/x32/tst-size_t-wmemchr.c new file mode 100644 index 0000000000..877801d646 --- /dev/null +++ b/sysdeps/x86_64/x32/tst-size_t-wmemchr.c @@ -0,0 +1,20 @@ +/* Test wmemchr 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 + . */ + +#define WIDE 1 +#include "tst-size_t-memchr.c" -- cgit 1.4.1