154 lines
4.7 KiB
Diff
154 lines
4.7 KiB
Diff
From c7c54f65b080affb87a1513dee449c8ad6143c8b Mon Sep 17 00:00:00 2001
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From: "H.J. Lu" <hjl.tools@gmail.com>
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Date: Mon, 21 Jan 2019 11:35:18 -0800
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Subject: [PATCH] x86-64 strncpy: Properly handle the length parameter [BZ#
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24097]
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Content-type: text/plain; charset=UTF-8
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On x32, the size_t parameter may be passed in the lower 32 bits of a
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64-bit register with the non-zero upper 32 bits. The string/memory
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functions written in assembly can only use the lower 32 bits of a
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64-bit register as length or must clear the upper 32 bits before using
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the full 64-bit register for length.
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This pach fixes strncpy for x32. Tested on x86-64 and x32. On x86-64,
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libc.so is the same with and withou the fix.
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[BZ# 24097]
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CVE-2019-6488
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* sysdeps/x86_64/multiarch/strcpy-avx2.S: Use RDX_LP for length.
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* sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S: Likewise.
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* sysdeps/x86_64/multiarch/strcpy-ssse3.S: Likewise.
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* sysdeps/x86_64/x32/Makefile (tests): Add tst-size_t-strncpy.
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* sysdeps/x86_64/x32/tst-size_t-strncpy.c: New file.
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---
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.../x86_64/multiarch/strcpy-sse2-unaligned.S | 4 +-
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sysdeps/x86_64/multiarch/strcpy-ssse3.S | 6 +-
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sysdeps/x86_64/x32/Makefile | 2 +-
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sysdeps/x86_64/x32/tst-size_t-strncpy.c | 58 +++++++++++++++++++
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4 files changed, 64 insertions(+), 6 deletions(-)
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create mode 100644 sysdeps/x86_64/x32/tst-size_t-strncpy.c
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Conflicts:
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ChangeLog
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(removed)
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sysdeps/x86_64/multiarch/strcpy-avx2.S
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(skipped, only needed for x32 arch)
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diff --git a/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S b/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S
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index 72bf7e85..50aca22d 100644
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--- a/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S
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+++ b/sysdeps/x86_64/multiarch/strcpy-sse2-unaligned.S
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@@ -40,8 +40,8 @@
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.text
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ENTRY (STRCPY)
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# ifdef USE_AS_STRNCPY
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- mov %rdx, %r8
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- test %r8, %r8
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+ mov %RDX_LP, %R8_LP
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+ test %R8_LP, %R8_LP
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jz L(ExitZero)
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# endif
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mov %rsi, %rcx
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diff --git a/sysdeps/x86_64/multiarch/strcpy-ssse3.S b/sysdeps/x86_64/multiarch/strcpy-ssse3.S
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index 9858d0c4..0a62814a 100644
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--- a/sysdeps/x86_64/multiarch/strcpy-ssse3.S
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+++ b/sysdeps/x86_64/multiarch/strcpy-ssse3.S
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@@ -31,13 +31,13 @@ ENTRY (STRCPY)
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mov %rsi, %rcx
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# ifdef USE_AS_STRNCPY
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- mov %rdx, %r8
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+ mov %RDX_LP, %R8_LP
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# endif
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mov %rdi, %rdx
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# ifdef USE_AS_STRNCPY
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- test %r8, %r8
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+ test %R8_LP, %R8_LP
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jz L(Exit0)
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- cmp $8, %r8
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+ cmp $8, %R8_LP
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jbe L(StrncpyExit8Bytes)
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# endif
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cmpb $0, (%rcx)
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diff --git a/sysdeps/x86_64/x32/Makefile b/sysdeps/x86_64/x32/Makefile
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index db302839..2a9e20a9 100644
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--- a/sysdeps/x86_64/x32/Makefile
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+++ b/sysdeps/x86_64/x32/Makefile
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@@ -8,7 +8,7 @@ endif
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ifeq ($(subdir),string)
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tests += tst-size_t-memchr tst-size_t-memcmp tst-size_t-memcpy \
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tst-size_t-memrchr tst-size_t-memset tst-size_t-strncasecmp \
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- tst-size_t-strncmp
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+ tst-size_t-strncmp tst-size_t-strncpy
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endif
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ifeq ($(subdir),wcsmbs)
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diff --git a/sysdeps/x86_64/x32/tst-size_t-strncpy.c b/sysdeps/x86_64/x32/tst-size_t-strncpy.c
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new file mode 100644
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index 00000000..4dec71e6
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--- /dev/null
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+++ b/sysdeps/x86_64/x32/tst-size_t-strncpy.c
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@@ -0,0 +1,58 @@
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+/* Test strncpy with size_t in the lower 32 bits of 64-bit register.
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+ Copyright (C) 2019 Free Software Foundation, Inc.
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+ This file is part of the GNU C Library.
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+
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+ The GNU C Library is free software; you can redistribute it and/or
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+ modify it under the terms of the GNU Lesser General Public
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+ License as published by the Free Software Foundation; either
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+ version 2.1 of the License, or (at your option) any later version.
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+
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+ The GNU C Library is distributed in the hope that it will be useful,
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+ but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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+ Lesser General Public License for more details.
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+
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+ You should have received a copy of the GNU Lesser General Public
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+ License along with the GNU C Library; if not, see
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+ <http://www.gnu.org/licenses/>. */
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+
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+#define TEST_NAME "strncpy"
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+#include "test-size_t.h"
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+
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+IMPL (strncpy, 1)
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+
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+typedef char *(*proto_t) (char *, const char*, size_t);
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+
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+static void *
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+__attribute__ ((noinline, noclone))
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+do_strncpy (parameter_t a, parameter_t b)
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+{
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+ return CALL (&b, a.p, b.p, a.len);
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+}
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+
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+static int
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+test_main (void)
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+{
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+ test_init ();
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+
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+ parameter_t dest = { { page_size }, buf1 };
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+ parameter_t src = { { 0 }, buf2 };
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+
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+ int ret = 0;
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+ FOR_EACH_IMPL (impl, 0)
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+ {
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+ src.fn = impl->fn;
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+ do_strncpy (dest, src);
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+ int res = strncmp (dest.p, src.p, dest.len);
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+ if (res)
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+ {
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+ error (0, 0, "Wrong result in function %s: %i != 0",
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+ impl->name, res);
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+ ret = 1;
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+ }
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+ }
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+
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+ return ret ? EXIT_FAILURE : EXIT_SUCCESS;
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+}
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+
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+#include <support/test-driver.c>
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--
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GitLab
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