1 /* $OpenBSD: stack_protector.c,v 1.15 2013/12/28 18:42:42 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, 20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 * 28 */ 29 30 #include <sys/param.h> 31 #include <signal.h> 32 #include <string.h> 33 #include <syslog.h> 34 #include <unistd.h> 35 36 void __stack_smash_handler(char func[], int damaged __attribute__((unused))); 37 38 /*ARGSUSED*/ 39 void 40 __stack_smash_handler(char func[], int damaged) 41 { 42 struct syslog_data sdata = SYSLOG_DATA_INIT; 43 const char message[] = "stack overflow in function %s"; 44 struct sigaction sa; 45 sigset_t mask; 46 47 /* Immediately block all signal handlers from running code */ 48 sigfillset(&mask); 49 sigdelset(&mask, SIGABRT); 50 sigprocmask(SIG_BLOCK, &mask, NULL); 51 52 /* This may fail on a chroot jail... */ 53 syslog_r(LOG_CRIT, &sdata, message, func); 54 55 bzero(&sa, sizeof(struct sigaction)); 56 sigemptyset(&sa.sa_mask); 57 sa.sa_flags = 0; 58 sa.sa_handler = SIG_DFL; 59 sigaction(SIGABRT, &sa, NULL); 60 61 kill(getpid(), SIGABRT); 62 63 _exit(127); 64 } 65