src/patches/glibc-2.3.3-ssp_frandom-2.patch

   1 Submitted By: Robert Connolly <cendres at videotron dot ca> (ashes)
   2 Date: 2004-04-24
   3 Initial Package Version: 2.3.3
   4 Origin: http://www.research.ibm.com/trl/projects/security/ssp/
   5         http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/sys/stack_protector.c
   6 Description: Smashing Stack Protector - This patch adds guard functions to
   7 Glibc.
   8
   9 This patch depends on erandom sysctl from:
  10 http://frandom.sourceforge.net/
  11 http://www.linuxfromscratch.org/hints/downloads/files/entropy.txt
  12
  13 Also see:
  14 http://www.research.ibm.com/trl/projects/security/ssp/
  15 http://www.linuxfromscratch.org/hlfs/
  16 http://www.linuxfromscratch.org/hints/downloads/files/ssp.txt
  17
  18 diff -Naur glibc-2.3-20040418.orig/sysdeps/generic/libc-start.c glibc-2.3-20040418.ssp-frandom/sysdeps/generic/libc-start.c
  19 --- glibc-2.3-20040418.orig/sysdeps/generic/libc-start.c        2004-03-31 01:46:43.000000000 +0000
  20 +++ glibc-2.3-20040418.ssp-frandom/sysdeps/generic/libc-start.c 2004-04-25 07:07:34.000000000 +0000
  21 @@ -188,6 +188,8 @@
  22      GLRO(dl_debug_printf) ("\ntransferring control: %s\n\n", argv[0]);
  23  #endif
  24
  25 +  __guard_setup ();
  26 +
  27  #ifdef HAVE_CLEANUP_JMP_BUF
  28    /* Memory for the cancellation buffer.  */
  29    struct pthread_unwind_buf unwind_buf;
  30 diff -Naur glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/Dist glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/Dist
  31 --- glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/Dist        2003-09-24 05:04:29.000000000 +0000
  32 +++ glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/Dist 2004-04-25 07:09:46.000000000 +0000
  33 @@ -1,3 +1,4 @@
  34 +stack_protector.c
  35  bits/initspin.h
  36  cmsg_nxthdr.c
  37  dl-brk.c
  38 diff -Naur glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/Makefile glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/Makefile
  39 --- glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/Makefile    2004-04-03 07:45:26.000000000 +0000
  40 +++ glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/Makefile     2004-04-25 07:10:02.000000000 +0000
  41 @@ -1,5 +1,5 @@
  42  ifeq ($(subdir),csu)
  43 -sysdep_routines += errno-loc
  44 +sysdep_routines += errno-loc stack_protector
  45  endif
  46
  47  ifeq ($(subdir),assert)
  48 diff -Naur glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/Versions glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/Versions
  49 --- glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/Versions    2004-03-19 00:13:55.000000000 +0000
  50 +++ glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/Versions     2004-04-25 07:08:58.000000000 +0000
  51 @@ -108,6 +108,7 @@
  52    GLIBC_2.3.2 {
  53      # New kernel interfaces.
  54      epoll_create; epoll_ctl; epoll_wait;
  55 +       __guard; __guard_setup; __stack_smash_handler;
  56    }
  57    GLIBC_2.3.3 {
  58      gnu_dev_major; gnu_dev_minor; gnu_dev_makedev;
  59 diff -Naur glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/stack_protector.c glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/stack_protector.c
  60 --- glibc-2.3-20040418.orig/sysdeps/unix/sysv/linux/stack_protector.c   1970-01-01 00:00:00.000000000 +0000
  61 +++ glibc-2.3-20040418.ssp-frandom/sysdeps/unix/sysv/linux/stack_protector.c    2004-04-25 07:24:27.000000000 +0000
  62 @@ -0,0 +1,160 @@
  63 +/*     $hlfs: ssp.c,v 1.1 2004/04/24 00:00:00 robert Exp $     */
  64 +
  65 +/* Most of this code was copied from the gcc patch, libgcc2.c hunk, from
  66 + *     http://www.trl.ibm.com/projects/security/ssp/
  67 + * And therefore this code is part of gcc.
  68 + */
  69 +
  70 +/* Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
  71 +   2000, 2001, 2002  Free Software Foundation, Inc.
  72 +
  73 +This file is part of GCC.
  74 +
  75 +GCC is free software; you can redistribute it and/or modify it under
  76 +the terms of the GNU General Public License as published by the Free
  77 +Software Foundation; either version 2, or (at your option) any later
  78 +version.
  79 +
  80 +In addition to the permissions in the GNU General Public License, the
  81 +Free Software Foundation gives you unlimited permission to link the
  82 +compiled version of this file into combinations with other programs,
  83 +and to distribute those combinations without any restriction coming
  84 +from the use of this file.  (The General Public License restrictions
  85 +do apply in other respects; for example, they cover modification of
  86 +the file, and distribution when not linked into a combine
  87 +executable.)
  88 +
  89 +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  90 +WARRANTY; without even the implied warranty of MERCHANTABILITY or
  91 +FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  92 +for more details.
  93 +
  94 +You should have received a copy of the GNU General Public License
  95 +along with GCC; see the file COPYING.  If not, write to the Free
  96 +Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  97 +02111-1307, USA.  */
  98 +
  99 +/* Some portions of this code were copied from
 100 + *     http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/sys/stack_protector.c
 101 + * And hence a dual license.
 102 + */
 103 +
 104 +/*
 105 + * Copyright (c) 2002 Hiroaki Etoh, Federico G. Schwindt, and Miodrag Vallat.
 106 + * All rights reserved.
 107 + *
 108 + * Redistribution and use in source and binary forms, with or without
 109 + * modification, are permitted provided that the following conditions
 110 + * are met:
 111 + * 1. Redistributions of source code must retain the above copyright
 112 + *    notice, this list of conditions and the following disclaimer.
 113 + * 2. Redistributions in binary form must reproduce the above copyright
 114 + *    notice, this list of conditions and the following disclaimer in the
 115 + *    documentation and/or other materials provided with the distribution.
 116 + *
 117 + * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 118 + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 119 + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 120 + * DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT,
 121 + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 122 + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 123 + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 124 + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 125 + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 126 + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 127 + * POSSIBILITY OF SUCH DAMAGE.
 128 + *
 129 + */
 130 +
 131 +#include <stdio.h>
 132 +#include <string.h>
 133 +#include <fcntl.h>
 134 +#include <unistd.h>
 135 +#include <sys/sysctl.h>
 136 +
 137 +#include <signal.h>
 138 +
 139 +#include <sys/types.h>
 140 +#include <sys/socket.h>
 141 +#include <sys/un.h>
 142 +
 143 +#include <sys/syslog.h>
 144 +#ifndef _PATH_LOG
 145 +#define _PATH_LOG "/dev/log"
 146 +#endif
 147 +
 148 +long __guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
 149 +
 150 +void __guard_setup (void)
 151 +{
 152 +       int i, mib[3];
 153 +       size_t len;
 154 +
 155 +       if (__guard[0] != 0)
 156 +               return;
 157 +
 158 +       /* Random is another depth in Linux, hence an array of 3. */
 159 +       mib[0] = CTL_KERN;
 160 +       mib[1] = KERN_RANDOM;
 161 +       mib[2] = RANDOM_ERANDOM;
 162 +
 163 +       len = 4;
 164 +       for (i = 0; i < sizeof(__guard) / 4; i++) {
 165 +               if (sysctl(mib, 3, (char *)&((int *)__guard)[i],
 166 +                   &len, NULL, 0) == -1)
 167 +                       break;
 168 +       }
 169 +
 170 +       if (i < sizeof(__guard) / 4) {
 171 +               /* If sysctl was unsuccessful, use the "terminator canary". */
 172 +               ((char *)__guard)[0] = 0; ((char*)__guard)[1] = 0;
 173 +               ((char *)__guard)[2] = '\n'; ((char *)__guard)[3] = 255;
 174 +       }
 175 +}
 176 +
 177 +void __stack_smash_handler (char func[], int damaged)
 178 +{
 179 +       extern char * __progname;
 180 +       const char message[] = ": stack smashing attack in function ";
 181 +       int bufsz = 512, len;
 182 +       char buf[bufsz];
 183 +       int LogFile;
 184 +       struct sockaddr_un SyslogAddr;  /* AF_UNIX address of local logger */
 185 +
 186 +       sigset_t mask;
 187 +       sigfillset(&mask);
 188 +       sigdelset(&mask, SIGABRT);  /* Block all signal handlers */
 189 +       sigprocmask(SIG_BLOCK, &mask, NULL); /* except SIGABRT */
 190 +
 191 +       strcpy(buf, "<2>"); len=3;    /* send LOG_CRIT */
 192 +       strncat(buf, __progname, bufsz-len-1); len = strlen(buf);
 193 +       if (bufsz>len) {strncat(buf, message, bufsz-len-1); len = strlen(buf);}
 194 +       if (bufsz>len) {strncat(buf, func, bufsz-len-1); len = strlen(buf);}
 195 +       /* print error message */
 196 +       write (STDERR_FILENO, buf+3, len-3);
 197 +       if ((LogFile = socket(AF_UNIX, SOCK_DGRAM, 0)) != -1) {
 198 +               /*
 199 +               * Send "found" message to the "/dev/log" path
 200 +               */
 201 +               SyslogAddr.sun_family = AF_UNIX;
 202 +               (void)strncpy(SyslogAddr.sun_path, _PATH_LOG,
 203 +                       sizeof(SyslogAddr.sun_path) - 1);
 204 +               SyslogAddr.sun_path[sizeof(SyslogAddr.sun_path) - 1] = '\0';
 205 +               sendto(LogFile, buf, len, 0, (struct sockaddr *)&SyslogAddr,
 206 +                       sizeof(SyslogAddr));
 207 +       }
 208 +
 209 +       /* Make sure the default handler is associated with SIGABRT */
 210 +       struct sigaction sa;
 211 +
 212 +       memset(&sa, 0, sizeof(struct sigaction));
 213 +       sigfillset(&sa.sa_mask);    /* Block all signals */
 214 +       sa.sa_flags = 0;
 215 +       sa.sa_handler = SIG_DFL;
 216 +       sigaction(SIGABRT, &sa, NULL);
 217 +
 218 +       (void)kill(getpid(), SIGABRT);
 219 +
 220 +       _exit(127);
 221 +}
 222 +