diff options
author | kan <kan@FreeBSD.org> | 2007-05-19 04:31:43 +0000 |
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committer | kan <kan@FreeBSD.org> | 2007-05-19 04:31:43 +0000 |
commit | 34d4c477d20637aaa12f006d030d9448cffa87e9 (patch) | |
tree | e536fa907be1f1156ea18c438f58f45f4e484711 /lib/libc/sys/stack_protector.c | |
parent | ebf45ed0c9ac33acf511d695cfa9c23664f0096f (diff) | |
download | FreeBSD-src-34d4c477d20637aaa12f006d030d9448cffa87e9.zip FreeBSD-src-34d4c477d20637aaa12f006d030d9448cffa87e9.tar.gz |
Follow NetBSD, OpenBSD and DragonfyBSD project and add BSD-licensed
SSP functions into FreeBSD libc. Use the same file name and location
for consistency with other projects.
Diffstat (limited to 'lib/libc/sys/stack_protector.c')
-rw-r--r-- | lib/libc/sys/stack_protector.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/lib/libc/sys/stack_protector.c b/lib/libc/sys/stack_protector.c new file mode 100644 index 0000000..08a68f1 --- /dev/null +++ b/lib/libc/sys/stack_protector.c @@ -0,0 +1,119 @@ +/* $FreeBSD$ */ +/* $NetBSD: stack_protector.c,v 1.4 2006/11/22 17:23:25 christos Exp $ */ +/* $OpenBSD: stack_protector.c,v 1.10 2006/03/31 05:34:44 deraadt Exp $ */ +/* + * Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/sysctl.h> +#include <sys/types.h> +#include <signal.h> +#include <string.h> +#include <syslog.h> +#include <unistd.h> + +extern int __sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, + void *newp, size_t newlen); + +long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; +static void __guard_setup(void) __attribute__((__constructor__, __used__)); +static void __fail(const char *); +void __stack_chk_fail(void); +void __chk_fail(void); +void __stack_chk_fail_local(void); + +/*LINTED used*/ +static void +__guard_setup(void) +{ + int mib[2]; + size_t len; + + if (__stack_chk_guard[0] != 0) + return; + + mib[0] = CTL_KERN; + mib[1] = KERN_ARND; + + len = sizeof(__stack_chk_guard); + if (__sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || + len != sizeof(__stack_chk_guard)) { + /* If sysctl was unsuccessful, use the "terminator canary". */ + ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; + ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; + ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; + ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; + } +} + +/*ARGSUSED*/ +static void +__fail(const char *msg) +{ + struct sigaction sa; + sigset_t mask; + + /* Immediately block all signal handlers from running code */ + (void)sigfillset(&mask); + (void)sigdelset(&mask, SIGABRT); + (void)sigprocmask(SIG_BLOCK, &mask, NULL); + + /* This may fail on a chroot jail... */ + syslog(LOG_CRIT, msg); + + (void)memset(&sa, 0, sizeof(sa)); + (void)sigemptyset(&sa.sa_mask); + sa.sa_flags = 0; + sa.sa_handler = SIG_DFL; + (void)sigaction(SIGABRT, &sa, NULL); + (void)kill(getpid(), SIGABRT); + _exit(127); +} + +void +__stack_chk_fail(void) +{ + __fail("stack overflow detected; terminated"); +} + +void +__chk_fail(void) +{ + __fail("buffer overflow detected; terminated"); +} + +void +#ifdef __GNUC__ +__attribute__((visibility ("hidden"))) +#endif +__stack_chk_fail_local(void) +{ + __stack_chk_fail(); +} |