glibc/debug/fortify_fail.c
H.J. Lu 422ff87c24 Avoid accessing corrupted stack from __stack_chk_fail [BZ #21752]
__libc_argv[0] points to address on stack and __libc_secure_getenv
accesses environment variables which are on stack.  We should avoid
accessing stack when stack is corrupted.

This patch also renames function argument in __fortify_fail_abort
from do_backtrace to need_backtrace to avoid confusion with do_backtrace
from enum __libc_message_action.

	[BZ #21752]
	* debug/fortify_fail.c (__fortify_fail_abort): Don't pass down
	__libc_argv[0] if we aren't doing backtrace.  Rename do_backtrace
	to need_backtrace.
	* sysdeps/posix/libc_fatal.c (__libc_message): Don't call
	__libc_secure_getenv if we aren't doing backtrace.
2017-07-24 06:06:24 -07:00

49 lines
1.6 KiB
C

/* Copyright (C) 2007-2017 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/>. */
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
extern char **__libc_argv attribute_hidden;
void
__attribute__ ((noreturn)) internal_function
__fortify_fail_abort (_Bool need_backtrace, const char *msg)
{
/* The loop is added only to keep gcc happy. Don't pass down
__libc_argv[0] if we aren't doing backtrace since __libc_argv[0]
may point to the corrupted stack. */
while (1)
__libc_message (need_backtrace ? (do_abort | do_backtrace) : do_abort,
"*** %s ***: %s terminated\n",
msg,
(need_backtrace && __libc_argv[0] != NULL
? __libc_argv[0] : "<unknown>"));
}
void
__attribute__ ((noreturn)) internal_function
__fortify_fail (const char *msg)
{
__fortify_fail_abort (true, msg);
}
libc_hidden_def (__fortify_fail)
libc_hidden_def (__fortify_fail_abort)