X-Git-Url: https://git.saurik.com/apple/libc.git/blobdiff_plain/7c78c5292a74d7cc20fc03e02fbfc976e072f928..refs/heads/master:/sys/OpenBSD/stack_protector.c

diff --git a/sys/OpenBSD/stack_protector.c b/sys/OpenBSD/stack_protector.c
index 368e365..7ac7c7b 100644
--- a/sys/OpenBSD/stack_protector.c
+++ b/sys/OpenBSD/stack_protector.c
@@ -1,3 +1,5 @@
+/*	$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.
@@ -25,51 +27,106 @@
  *
  */
 
-#if defined(LIBC_SCCS) && !defined(list)
-static char rcsid[] = "$OpenBSD: stack_protector.c,v 1.3 2002/12/10 08:53:42 etoh Exp $";
-#endif
-
 #include <sys/param.h>
-#include <sys/sysctl.h>
-#include <syslog.h>
+#include <signal.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#if __has_include(<CrashReporterClient.h>)
+#include <CrashReporterClient.h>
+#else
+#define CRSetCrashLogMessage(...)
+#endif
+#include "libproc.h"
+#include "_simple.h"
 
-long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
-static void __guard_setup(void) __attribute__ ((constructor));
-void __stack_smash_handler(char func[], int damaged __attribute__((unused)));
+#define	GUARD_MAX 8
+long __stack_chk_guard[GUARD_MAX] = {0, 0, 0, 0, 0, 0, 0, 0};
+void __abort(void) __cold __dead2;
+void __guard_setup(const char *apple[]) __attribute__ ((visibility ("hidden")));
+void __stack_chk_fail(void);
 
 static void
-__guard_setup(void)
+__guard_from_kernel(const char *str)
 {
-  int fd;
-  if (__guard[0]!=0) return;
-  fd = open ("/dev/urandom", 0);
-  if (fd != -1) {
-    ssize_t size = read (fd, (char*)&__guard, sizeof(__guard));
-    close (fd) ;
-    if (size == sizeof(__guard)) return;
-  }
-  /* If a random generator can't be used, the protector switches the guard
-     to the "terminator canary" */
-  ((char*)__guard)[0] = 0; ((char*)__guard)[1] = 0;
-  ((char*)__guard)[2] = '\n'; ((char*)__guard)[3] = 255;
+	unsigned long long val;
+	char tmp[20], *p;
+	int idx = 0;
+
+	/* Skip over the 'stack_guard=' key to the list of values */
+	str = strchr(str, '=');
+	if (str == NULL)
+		return;
+	str++;
+
+	while (str && idx < GUARD_MAX) {
+		/*
+		 * Pull the next numeric string out of the list and convert it to
+		 * a real number.
+		 */
+		strlcpy(tmp, str, 20);
+		p = strchr(tmp, ',');
+		if (p)
+			*p = '\0';
+		val = strtoull(tmp, NULL, 0);
+		__stack_chk_guard[idx] = (long)(val & ((unsigned long) -1));
+		idx++;
+		if ((str = strchr(str, ',')) != NULL)
+			str++;
+	}
 }
 
 void
-__stack_smash_handler(char func[], int damaged)
+__guard_setup(const char *apple[])
 {
-  const char message[] = "stack overflow in function %s";
-  struct sigaction sa;
+	int fd;
+	size_t len;
+	const char **p;
+
+	if (__stack_chk_guard[0] != 0)
+		return;
 
-  /* this may fail on a chroot jail, though luck */
-  syslog(LOG_CRIT, message, func);
+	for (p = apple; p && *p; p++) {
+		if (strstr(*p, "stack_guard") == *p) {
+			__guard_from_kernel(*p);
+			bzero((void*)*p, strlen(*p));
+			if (__stack_chk_guard[0] != 0) {
+				return;
+			}
+		}
+	}
 
-  bzero(&sa, sizeof(struct sigaction));
-  sigemptyset(&sa.sa_mask);
-  sa.sa_flags = 0;
-  sa.sa_handler = SIG_DFL;
-  sigaction(SIGABRT, &sa, NULL);
+	fd = open ("/dev/urandom", 0);
+	if (fd != -1) {
+		len = read (fd, (char*)&__stack_chk_guard, sizeof(__stack_chk_guard));
+		close(fd);
+		if (len == sizeof(__stack_chk_guard) && 
+                    *__stack_chk_guard != 0)
+			return;
+	}
+
+	/* If If a random generator can't be used, the protector switches the guard
+           to the "terminator canary" */
+	((unsigned char *)__stack_chk_guard)[0] = 0;
+	((unsigned char *)__stack_chk_guard)[1] = 0;
+	((unsigned char *)__stack_chk_guard)[2] = '\n';
+	((unsigned char *)__stack_chk_guard)[3] = 255;
+}
+
+static const char *stackoverflow_msg = "stack buffer overflow";
+
+void
+__stack_chk_fail()
+{
+	CRSetCrashLogMessage(stackoverflow_msg);
 
-  kill(getpid(), SIGABRT);
+	/* This may fail on a chroot jail... */
+	char prog[2*MAXCOMLEN+1] = {0};
+	proc_name(getpid(), prog, 2*MAXCOMLEN);
+	prog[2*MAXCOMLEN] = 0;
+	_simple_asl_log_prog(ASL_LEVEL_CRIT, "user", stackoverflow_msg, prog);
 
-  _exit(127);
+	__abort();
 }