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/* Copyright (C) 2005, 2007 Free Software Foundation, Inc. |
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/* Copyright (C) 2005 Free Software Foundation, Inc. |
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This file is part of the GNU C Library. |
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This file is part of the GNU C Library. |
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The GNU C Library is free software; you can redistribute it and/or |
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The GNU C Library is free software; you can redistribute it and/or |
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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02111-1307 USA. */ |
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02111-1307 USA. */ |
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#include <stdio.h> |
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/* Copyright (C) 2006-2007 Gentoo Foundation Inc. |
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* License terms as above. |
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* |
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* Hardened Gentoo SSP handler |
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* |
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* An SSP failure handler that does not use functions from the rest of |
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* glibc; it uses the INTERNAL_SYSCALL methods directly. This ensures |
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* no possibility of recursion into the handler. |
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* |
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* Direct all bug reports to http://bugs.gentoo.org/ |
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* |
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* Re-written from the glibc-2.3 Hardened Gentoo SSP handler |
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* by Kevin F. Quinn - <kevquinn[@]gentoo.org> |
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* |
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* The following people contributed to the glibc-2.3 Hardened |
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* Gentoo SSP handler, from which this implementation draws much: |
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* |
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* Ned Ludd - <solar[@]gentoo.org> |
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* Alexander Gabert - <pappy[@]gentoo.org> |
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* The PaX Team - <pageexec[@]freemail.hu> |
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* Peter S. Mazinger - <ps.m[@]gmx.net> |
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* Yoann Vandoorselaere - <yoann[@]prelude-ids.org> |
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* Robert Connolly - <robert[@]linuxfromscratch.org> |
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* Cory Visi <cory[@]visi.name> |
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* Mike Frysinger <vapier[@]gentoo.org> |
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*/ |
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#include <errno.h> |
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#include <stdlib.h> |
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#include <stdlib.h> |
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#include <unistd.h> |
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#include <signal.h> |
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#include <sys/types.h> |
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#include <sysdep-cancel.h> |
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#include <sys/syscall.h> |
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#include <bp-checks.h> |
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#include <kernel-features.h> |
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#include <alloca.h> |
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/* from sysdeps */ |
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#include <socketcall.h> |
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/* for the stuff in bits/socket.h */ |
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#include <sys/socket.h> |
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#include <sys/un.h> |
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|
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/* Sanity check on SYSCALL macro names - force compilation |
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* failure if the names used here do not exist |
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*/ |
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#if !defined __NR_socketcall && !defined __NR_socket |
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# error Cannot do syscall socket or socketcall |
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#endif |
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#if !defined __NR_socketcall && !defined __NR_connect |
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# error Cannot do syscall connect or socketcall |
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#endif |
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#ifndef __NR_write |
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# error Cannot do syscall write |
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#endif |
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#ifndef __NR_close |
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# error Cannot do syscall close |
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#endif |
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#ifndef __NR_getpid |
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# error Cannot do syscall getpid |
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#endif |
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#ifndef __NR_kill |
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# error Cannot do syscall kill |
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#endif |
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#ifndef __NR_exit |
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# error Cannot do syscall exit |
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#endif |
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#ifdef SSP_SMASH_DUMPS_CORE |
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# define ENABLE_SSP_SMASH_DUMPS_CORE 1 |
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# if !defined _KERNEL_NSIG && !defined _NSIG |
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# error No _NSIG or _KERNEL_NSIG for rt_sigaction |
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# endif |
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# if !defined __NR_sigaction && !defined __NR_rt_sigaction |
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# error Cannot do syscall sigaction or rt_sigaction |
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# endif |
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/* Although rt_sigaction expects sizeof(sigset_t) - it expects the size |
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* of the _kernel_ sigset_t which is not the same as the user sigset_t. |
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* Most arches have this as _NSIG bits - mips has _KERNEL_NSIG bits for |
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* some reason. |
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*/ |
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# ifdef _KERNEL_NSIG |
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# define _SSP_NSIG _KERNEL_NSIG |
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# else |
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# define _SSP_NSIG _NSIG |
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# endif |
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#else |
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# define _SSP_NSIG 0 |
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# define ENABLE_SSP_SMASH_DUMPS_CORE 0 |
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#endif |
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|
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/* Define DO_SIGACTION - default to newer rt signal interface but |
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* fallback to old as needed. |
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*/ |
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#ifdef __NR_rt_sigaction |
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# define DO_SIGACTION(signum, act, oldact) \ |
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INLINE_SYSCALL(rt_sigaction, 4, signum, act, oldact, _SSP_NSIG/8) |
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#else |
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# define DO_SIGACTION(signum, act, oldact) \ |
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INLINE_SYSCALL(sigaction, 3, signum, act, oldact) |
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#endif |
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|
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/* Define DO_SOCKET/DO_CONNECT functions to deal with socketcall vs socket/connect */ |
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#if defined(__NR_socket) && defined(__NR_connect) |
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# define USE_OLD_SOCKETCALL 0 |
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#else |
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# define USE_OLD_SOCKETCALL 1 |
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#endif |
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/* stub out the __NR_'s so we can let gcc optimize away dead code */ |
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#ifndef __NR_socketcall |
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# define __NR_socketcall 0 |
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#endif |
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#ifndef __NR_socket |
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# define __NR_socket 0 |
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#endif |
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#ifndef __NR_connect |
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# define __NR_connect 0 |
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#endif |
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#define DO_SOCKET(result, domain, type, protocol) \ |
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do { \ |
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if (USE_OLD_SOCKETCALL) { \ |
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socketargs[0] = domain; \ |
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socketargs[1] = type; \ |
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socketargs[2] = protocol; \ |
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socketargs[3] = 0; \ |
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result = INLINE_SYSCALL(socketcall, 2, SOCKOP_socket, socketargs); \ |
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} else \ |
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result = INLINE_SYSCALL(socket, 3, domain, type, protocol); \ |
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} while (0) |
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#define DO_CONNECT(result, sockfd, serv_addr, addrlen) \ |
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do { \ |
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if (USE_OLD_SOCKETCALL) { \ |
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socketargs[0] = sockfd; \ |
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socketargs[1] = (unsigned long int)serv_addr; \ |
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socketargs[2] = addrlen; \ |
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socketargs[3] = 0; \ |
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result = INLINE_SYSCALL(socketcall, 2, SOCKOP_connect, socketargs); \ |
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} else \ |
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result = INLINE_SYSCALL(connect, 3, sockfd, serv_addr, addrlen); \ |
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} while (0) |
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#ifndef _PATH_LOG |
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# define _PATH_LOG "/dev/log" |
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#endif |
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static const char path_log[] = _PATH_LOG; |
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/* For building glibc with SSP switched on, define __progname to a |
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* constant if building for the run-time loader, to avoid pulling |
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* in more of libc.so into ld.so |
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*/ |
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#ifdef IS_IN_rtld |
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static char *__progname = "<rtld>"; |
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#else |
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extern char *__progname; |
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#endif |
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/* Common handler code, used by stack_chk_fail and __stack_smash_handler |
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* Inlined to ensure no self-references to the handler within itself. |
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* Data static to avoid putting more than necessary on the stack, |
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* to aid core debugging. |
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* The copy in rtld must be hidden to ensure that it gets no relocations |
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* and thus does not crash if called during libc startup. |
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*/ |
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__attribute__ ((__noreturn__ , __always_inline__)) |
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#ifdef IS_IN_rtld |
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attribute_hidden |
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#endif |
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static inline void |
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__hardened_gentoo_stack_chk_fail(char func[], int damaged) |
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{ |
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#define MESSAGE_BUFSIZ 256 |
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static pid_t pid; |
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static int plen, i; |
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static char message[MESSAGE_BUFSIZ]; |
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static const char msg_ssa[] = ": stack smashing attack"; |
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static const char msg_inf[] = " in function "; |
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static const char msg_ssd[] = "*** stack smashing detected ***: "; |
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static const char msg_terminated[] = " - terminated\n"; |
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static const char msg_unknown[] = "<unknown>"; |
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static int log_socket, connect_result; |
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static struct sockaddr_un sock; |
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static unsigned long int socketargs[4]; |
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/* Build socket address |
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*/ |
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sock.sun_family = AF_UNIX; |
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i = 0; |
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while ((path_log[i] != '\0') && (i<(sizeof(sock.sun_path)-1))) { |
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sock.sun_path[i] = path_log[i]; |
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i++; |
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} |
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sock.sun_path[i] = '\0'; |
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/* Try SOCK_DGRAM connection to syslog */ |
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connect_result = -1; |
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DO_SOCKET(log_socket, AF_UNIX, SOCK_DGRAM, 0); |
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if (log_socket != -1) |
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DO_CONNECT(connect_result, log_socket, &sock, sizeof(sock)); |
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if (connect_result == -1) { |
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if (log_socket != -1) |
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INLINE_SYSCALL(close, 1, log_socket); |
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/* Try SOCK_STREAM connection to syslog */ |
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DO_SOCKET(log_socket, AF_UNIX, SOCK_STREAM, 0); |
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if (log_socket != -1) |
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DO_CONNECT(connect_result, log_socket, &sock, sizeof(sock)); |
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} |
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/* Build message. Messages are generated both in the old style and new style, |
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* so that log watchers that are configured for the old-style message continue |
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* to work. |
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*/ |
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#define strconcat(str) \ |
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{i=0; while ((str[i] != '\0') && ((i+plen)<(MESSAGE_BUFSIZ-1))) \ |
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{\ |
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message[plen+i]=str[i];\ |
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i++;\ |
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}\ |
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plen+=i;} |
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/* R.Henderson post-gcc-4 style message */ |
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plen = 0; |
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strconcat(msg_ssd); |
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if (__progname != (char *)0) |
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strconcat(__progname) |
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else |
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strconcat(msg_unknown); |
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strconcat(msg_terminated); |
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/* Write out error message to STDERR, to syslog if open */ |
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INLINE_SYSCALL(write, 3, STDERR_FILENO, message, plen); |
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if (connect_result != -1) |
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INLINE_SYSCALL(write, 3, log_socket, message, plen); |
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/* Dr. Etoh pre-gcc-4 style message */ |
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plen = 0; |
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if (__progname != (char *)0) |
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strconcat(__progname) |
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else |
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strconcat(msg_unknown); |
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strconcat(msg_ssa); |
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strconcat(msg_inf); |
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if (func != NULL) |
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strconcat(func) |
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else |
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strconcat(msg_unknown); |
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strconcat(msg_terminated); |
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/* Write out error message to STDERR, to syslog if open */ |
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INLINE_SYSCALL(write, 3, STDERR_FILENO, message, plen); |
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if (connect_result != -1) |
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INLINE_SYSCALL(write, 3, log_socket, message, plen); |
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extern char **__libc_argv attribute_hidden; |
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/* Write out error message to STDERR, to syslog if open */ |
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INLINE_SYSCALL(write, 3, STDERR_FILENO, message, plen); |
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if (connect_result != -1) |
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INLINE_SYSCALL(write, 3, log_socket, message, plen); |
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if (log_socket != -1) |
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INLINE_SYSCALL(close, 1, log_socket); |
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/* Suicide */ |
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pid = INLINE_SYSCALL(getpid, 0); |
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if (ENABLE_SSP_SMASH_DUMPS_CORE) { |
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static struct sigaction default_abort_act; |
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/* Remove any user-supplied handler for SIGABRT, before using it */ |
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default_abort_act.sa_handler = SIG_DFL; |
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default_abort_act.sa_sigaction = NULL; |
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__sigfillset(&default_abort_act.sa_mask); |
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default_abort_act.sa_flags = 0; |
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if (DO_SIGACTION(SIGABRT, &default_abort_act, NULL) == 0) |
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INLINE_SYSCALL(kill, 2, pid, SIGABRT); |
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} |
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/* Note; actions cannot be added to SIGKILL */ |
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INLINE_SYSCALL(kill, 2, pid, SIGKILL); |
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/* In case the kill didn't work, exit anyway |
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* The loop prevents gcc thinking this routine returns |
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*/ |
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while (1) |
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INLINE_SYSCALL(exit, 0); |
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} |
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void |
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__attribute__ ((__noreturn__)) |
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__attribute__ ((noreturn)) |
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void __stack_chk_fail(void) |
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__stack_chk_fail (void) |
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{ |
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{ |
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__fortify_fail ("stack smashing detected"); |
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__hardened_gentoo_stack_chk_fail(NULL, 0); |
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} |
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} |