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Differential D3448 Diff 8105 lib/libc/secure/stack_protector.c

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lib/libc/secure/stack_protector.c

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*/ */
#include <sys/cdefs.h> #include <sys/cdefs.h>
__FBSDID("$FreeBSD$"); __FBSDID("$FreeBSD$");
#include <sys/param.h> #include <sys/param.h>
#include <sys/sysctl.h> #include <sys/sysctl.h>
#include <sys/types.h> #include <sys/types.h>
#include <errno.h> #include <secure/security.h>
#include <link.h> #include <link.h>
#include <signal.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "libc_private.h" #include "libc_private.h"
extern int __sysctl(const int *name, u_int namelen, void *oldp, extern int __sysctl(const int *name, u_int namelen, void *oldp,
size_t *oldlenp, void *newp, size_t newlen); size_t *oldlenp, void *newp, size_t newlen);
long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
static void __guard_setup(void) __attribute__((__constructor__, __used__)); static void __guard_setup(void) __attribute__((__constructor__, __used__));
static void __fail(const char *); void __stack_chk_fail(void) __dead2;
void __stack_chk_fail(void);
void __chk_fail(void);
/*LINTED used*/ /*LINTED used*/
static void static void
__guard_setup(void) __guard_setup(void)
{ {
static const int mib[2] = { CTL_KERN, KERN_ARND }; static const int mib[2] = { CTL_KERN, KERN_ARND };
size_t len; size_t len;
int error; int error;
Show All 11 Lines if (__sysctl(mib, nitems(mib), __stack_chk_guard, &len, NULL, 0) ==
/* If sysctl was unsuccessful, use the "terminator canary". */ /* If sysctl was unsuccessful, use the "terminator canary". */
((unsigned char *)(void *)__stack_chk_guard)[0] = 0; ((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
((unsigned char *)(void *)__stack_chk_guard)[1] = 0; ((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
((unsigned char *)(void *)__stack_chk_guard)[3] = 255; ((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, "%s", 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 void
__stack_chk_fail(void) __stack_chk_fail(void)
{ {
__fail("stack overflow detected; terminated");
__secure_fail("stack overflow detected; terminated");
} }
void void
__chk_fail(void) __chk_fail(void)
{ {
__fail("buffer overflow detected; terminated");
__secure_fail("buffer overflow detected; terminated");
} }
#ifndef PIC #ifndef PIC
__weak_reference(__stack_chk_fail, __stack_chk_fail_local); __weak_reference(__stack_chk_fail, __stack_chk_fail_local);
#endif #endif