debug/tst-chk1.c

   1 /* Copyright (C) 2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Jakub Jelinek <jakub@redhat.com>, 2004.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <fcntl.h>
  21 #include <paths.h>
  22 #include <setjmp.h>
  23 #include <signal.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28
  29 char *temp_filename;
  30 static void do_prepare (void);
  31 static int do_test (void);
  32 #define PREPARE(argc, argv) do_prepare ()
  33 #define TEST_FUNCTION do_test ()
  34 #include "../test-skeleton.c"
  35
  36 static void
  37 do_prepare (void)
  38 {
  39   int temp_fd = create_temp_file ("tst-chk1.", &temp_filename);
  40   if (temp_fd == -1)
  41     {
  42       printf ("cannot create temporary file: %m\n");
  43       exit (1);
  44     }
  45
  46   const char *strs = "abcdefgh\nABCDEFGHI\nabcdefghij\nABCDEFGHIJ";
  47   if (write (temp_fd, strs, strlen (strs)) != strlen (strs))
  48     {
  49       puts ("could not write test strings into file");
  50       unlink (temp_filename);
  51       exit (1);
  52     }
  53 }
  54
  55 volatile int chk_fail_ok;
  56 volatile int ret;
  57 jmp_buf chk_fail_buf;
  58
  59 static void
  60 handler (int sig)
  61 {
  62   if (chk_fail_ok)
  63     {
  64       chk_fail_ok = 0;
  65       longjmp (chk_fail_buf, 1);
  66     }
  67   else
  68     _exit (127);
  69 }
  70
  71 char buf[10];
  72 volatile size_t l0;
  73 volatile char *p;
  74 const char *str1 = "JIHGFEDCBA";
  75 const char *str2 = "F";
  76 const char *str3 = "%s%n%s%n";
  77 const char *str4 = "Hello, ";
  78 const char *str5 = "World!\n";
  79 char buf2[10] = "%s";
  80 int num1 = 67;
  81 int num2 = 987654;
  82
  83 #define FAIL() \
  84   do { printf ("Failure on line %d\n", __LINE__); ret = 1; } while (0)
  85 #define CHK_FAIL_START \
  86   chk_fail_ok = 1;                              \
  87   if (! setjmp (chk_fail_buf))                  \
  88     {
  89 #define CHK_FAIL_END \
  90       chk_fail_ok = 0;                          \
  91       FAIL ();                                  \
  92     }
  93 #if __USE_FORTIFY_LEVEL >= 2
  94 #define CHK_FAIL2_START CHK_FAIL_START
  95 #define CHK_FAIL2_END CHK_FAIL_END
  96 #else
  97 #define CHK_FAIL2_START
  98 #define CHK_FAIL2_END
  99 #endif
 100
 101 static int
 102 do_test (void)
 103 {
 104   struct sigaction sa;
 105   sa.sa_handler = handler;
 106   sa.sa_flags = 0;
 107   sigemptyset (&sa.sa_mask);
 108
 109   sigaction (SIGABRT, &sa, NULL);
 110
 111   /* Avoid all the buffer overflow messages on stderr.  */
 112   int fd = open (_PATH_DEVNULL, O_WRONLY);
 113   if (fd == -1)
 114     close (STDERR_FILENO);
 115   else
 116     {
 117       dup2 (fd, STDERR_FILENO);
 118       close (fd);
 119     }
 120   setenv ("LIBC_FATAL_STDERR_", "1", 1);
 121
 122   struct A { char buf1[9]; char buf2[1]; } a;
 123
 124   printf ("Test checking routines at fortify level %d\n",
 125 #ifdef __USE_FORTIFY_LEVEL
 126           (int) __USE_FORTIFY_LEVEL
 127 #else
 128           0
 129 #endif
 130           );
 131
 132   /* These ops can be done without runtime checking of object size.  */
 133   memcpy (buf, "abcdefghij", 10);
 134   memmove (buf + 1, buf, 9);
 135   if (memcmp (buf, "aabcdefghi", 10))
 136     FAIL ();
 137
 138   if (mempcpy (buf + 5, "abcde", 5) != buf + 10 || memcmp (buf, "aabcdabcde", 10))
 139     FAIL ();
 140
 141   memset (buf + 8, 'j', 2);
 142   if (memcmp (buf, "aabcdabcjj", 10))
 143     FAIL ();
 144
 145   strcpy (buf + 4, "EDCBA");
 146   if (memcmp (buf, "aabcEDCBA", 10))
 147     FAIL ();
 148
 149   if (stpcpy (buf + 8, "F") != buf + 9 || memcmp (buf, "aabcEDCBF", 10))
 150     FAIL ();
 151
 152   strncpy (buf + 6, "X", 4);
 153   if (memcmp (buf, "aabcEDX\0\0", 10))
 154     FAIL ();
 155
 156   if (sprintf (buf + 7, "%s", "67") != 2 || memcmp (buf, "aabcEDX67", 10))
 157     FAIL ();
 158
 159   if (snprintf (buf + 7, 3, "%s", "987654") != 6
 160       || memcmp (buf, "aabcEDX98", 10))
 161     FAIL ();
 162
 163   /* These ops need runtime checking, but shouldn't __chk_fail.  */
 164   memcpy (buf, "abcdefghij", l0 + 10);
 165   memmove (buf + 1, buf, l0 + 9);
 166   if (memcmp (buf, "aabcdefghi", 10))
 167     FAIL ();
 168
 169   if (mempcpy (buf + 5, "abcde", l0 + 5) != buf + 10 || memcmp (buf, "aabcdabcde", 10))
 170     FAIL ();
 171
 172   memset (buf + 8, 'j', l0 + 2);
 173   if (memcmp (buf, "aabcdabcjj", 10))
 174     FAIL ();
 175
 176   strcpy (buf + 4, str1 + 5);
 177   if (memcmp (buf, "aabcEDCBA", 10))
 178     FAIL ();
 179
 180   if (stpcpy (buf + 8, str2) != buf + 9 || memcmp (buf, "aabcEDCBF", 10))
 181     FAIL ();
 182
 183   strncpy (buf + 6, "X", l0 + 4);
 184   if (memcmp (buf, "aabcEDX\0\0", 10))
 185     FAIL ();
 186
 187   if (sprintf (buf + 7, "%d", num1) != 2 || memcmp (buf, "aabcEDX67", 10))
 188     FAIL ();
 189
 190   if (snprintf (buf + 7, 3, "%d", num2) != 6 || memcmp (buf, "aabcEDX98", 10))
 191     FAIL ();
 192
 193   buf[l0 + 8] = '\0';
 194   strcat (buf, "A");
 195   if (memcmp (buf, "aabcEDX9A", 10))
 196     FAIL ();
 197
 198   buf[l0 + 7] = '\0';
 199   strncat (buf, "ZYXWV", l0 + 2);
 200   if (memcmp (buf, "aabcEDXZY", 10))
 201     FAIL ();
 202
 203   memcpy (a.buf1, "abcdefghij", l0 + 10);
 204   memmove (a.buf1 + 1, a.buf1, l0 + 9);
 205   if (memcmp (a.buf1, "aabcdefghi", 10))
 206     FAIL ();
 207
 208   if (mempcpy (a.buf1 + 5, "abcde", l0 + 5) != a.buf1 + 10
 209       || memcmp (a.buf1, "aabcdabcde", 10))
 210     FAIL ();
 211
 212   memset (a.buf1 + 8, 'j', l0 + 2);
 213   if (memcmp (a.buf1, "aabcdabcjj", 10))
 214     FAIL ();
 215
 216 #if __USE_FORTIFY_LEVEL < 2
 217   /* The following tests are supposed to crash with -D_FORTIFY_SOURCE=2
 218      and sufficient GCC support, as the string operations overflow
 219      from a.buf1 into a.buf2.  */
 220   strcpy (a.buf1 + 4, str1 + 5);
 221   if (memcmp (a.buf1, "aabcEDCBA", 10))
 222     FAIL ();
 223
 224   if (stpcpy (a.buf1 + 8, str2) != a.buf1 + 9 || memcmp (a.buf1, "aabcEDCBF", 10))
 225     FAIL ();
 226
 227   strncpy (a.buf1 + 6, "X", l0 + 4);
 228   if (memcmp (a.buf1, "aabcEDX\0\0", 10))
 229     FAIL ();
 230
 231   if (sprintf (a.buf1 + 7, "%d", num1) != 2 || memcmp (a.buf1, "aabcEDX67", 10))
 232     FAIL ();
 233
 234   if (snprintf (a.buf1 + 7, 3, "%d", num2) != 6
 235       || memcmp (a.buf1, "aabcEDX98", 10))
 236     FAIL ();
 237
 238   a.buf1[l0 + 8] = '\0';
 239   strcat (a.buf1, "A");
 240   if (memcmp (a.buf1, "aabcEDX9A", 10))
 241     FAIL ();
 242
 243   a.buf1[l0 + 7] = '\0';
 244   strncat (a.buf1, "ZYXWV", l0 + 2);
 245   if (memcmp (a.buf1, "aabcEDXZY", 10))
 246     FAIL ();
 247
 248 #endif
 249
 250 #if __USE_FORTIFY_LEVEL >= 1
 251   /* Now check if all buffer overflows are caught at runtime.  */
 252
 253   CHK_FAIL_START
 254   memcpy (buf + 1, "abcdefghij", l0 + 10);
 255   CHK_FAIL_END
 256
 257   CHK_FAIL_START
 258   memmove (buf + 2, buf + 1, l0 + 9);
 259   CHK_FAIL_END
 260
 261   CHK_FAIL_START
 262   p = mempcpy (buf + 6, "abcde", l0 + 5);
 263   CHK_FAIL_END
 264
 265   CHK_FAIL_START
 266   memset (buf + 9, 'j', l0 + 2);
 267   CHK_FAIL_END
 268
 269   CHK_FAIL_START
 270   strcpy (buf + 5, str1 + 5);
 271   CHK_FAIL_END
 272
 273   CHK_FAIL_START
 274   p = stpcpy (buf + 9, str2);
 275   CHK_FAIL_END
 276
 277   CHK_FAIL_START
 278   strncpy (buf + 7, "X", l0 + 4);
 279   CHK_FAIL_END
 280
 281   CHK_FAIL_START
 282   sprintf (buf + 8, "%d", num1);
 283   CHK_FAIL_END
 284
 285   CHK_FAIL_START
 286   snprintf (buf + 8, l0 + 3, "%d", num2);
 287   CHK_FAIL_END
 288
 289   memcpy (buf, str1 + 2, l0 + 9);
 290   CHK_FAIL_START
 291   strcat (buf, "AB");
 292   CHK_FAIL_END
 293
 294   memcpy (buf, str1 + 3, l0 + 8);
 295   CHK_FAIL_START
 296   strncat (buf, "ZYXWV", l0 + 3);
 297   CHK_FAIL_END
 298
 299   CHK_FAIL_START
 300   memcpy (a.buf1 + 1, "abcdefghij", l0 + 10);
 301   CHK_FAIL_END
 302
 303   CHK_FAIL_START
 304   memmove (a.buf1 + 2, a.buf1 + 1, l0 + 9);
 305   CHK_FAIL_END
 306
 307   CHK_FAIL_START
 308   p = mempcpy (a.buf1 + 6, "abcde", l0 + 5);
 309   CHK_FAIL_END
 310
 311   CHK_FAIL_START
 312   memset (a.buf1 + 9, 'j', l0 + 2);
 313   CHK_FAIL_END
 314
 315 #if __USE_FORTIFY_LEVEL >= 2
 316 # define O 0
 317 #else
 318 # define O 1
 319 #endif
 320
 321   CHK_FAIL_START
 322   strcpy (a.buf1 + (O + 4), str1 + 5);
 323   CHK_FAIL_END
 324
 325   CHK_FAIL_START
 326   p = stpcpy (a.buf1 + (O + 8), str2);
 327   CHK_FAIL_END
 328
 329   CHK_FAIL_START
 330   strncpy (a.buf1 + (O + 6), "X", l0 + 4);
 331   CHK_FAIL_END
 332
 333   CHK_FAIL_START
 334   sprintf (a.buf1 + (O + 7), "%d", num1);
 335   CHK_FAIL_END
 336
 337   CHK_FAIL_START
 338   snprintf (a.buf1 + (O + 7), l0 + 3, "%d", num2);
 339   CHK_FAIL_END
 340
 341   memcpy (a.buf1, str1 + (3 - O), l0 + 8 + O);
 342   CHK_FAIL_START
 343   strcat (a.buf1, "AB");
 344   CHK_FAIL_END
 345
 346   memcpy (a.buf1, str1 + (4 - O), l0 + 7 + O);
 347   CHK_FAIL_START
 348   strncat (a.buf1, "ZYXWV", l0 + 3);
 349   CHK_FAIL_END
 350 #endif
 351
 352   /* Now checks for %n protection.  */
 353
 354   /* Constant literals passed directly are always ok
 355      (even with warnings about possible bugs from GCC).  */
 356   int n1, n2;
 357   if (sprintf (buf, "%s%n%s%n", str2, &n1, str2, &n2) != 2
 358       || n1 != 1 || n2 != 2)
 359     FAIL ();
 360
 361   /* In this case the format string is not known at compile time,
 362      but resides in read-only memory, so is ok.  */
 363   if (snprintf (buf, 4, str3, str2, &n1, str2, &n2) != 2
 364       || n1 != 1 || n2 != 2)
 365     FAIL ();
 366
 367   strcpy (buf2 + 2, "%n%s%n");
 368   /* When the format string is writable and contains %n,
 369      with -D_FORTIFY_SOURCE=2 it causes __chk_fail.  */
 370   CHK_FAIL2_START
 371   if (sprintf (buf, buf2, str2, &n1, str2, &n1) != 2)
 372     FAIL ();
 373   CHK_FAIL2_END
 374
 375   CHK_FAIL2_START
 376   if (snprintf (buf, 3, buf2, str2, &n1, str2, &n1) != 2)
 377     FAIL ();
 378   CHK_FAIL2_END
 379
 380   /* But if there is no %n, even writable format string
 381      should work.  */
 382   buf2[6] = '\0';
 383   if (sprintf (buf, buf2 + 4, str2) != 1)
 384     FAIL ();
 385
 386   /* Constant literals passed directly are always ok
 387      (even with warnings about possible bugs from GCC).  */
 388   if (printf ("%s%n%s%n", str4, &n1, str5, &n2) != 14
 389       || n1 != 7 || n2 != 14)
 390     FAIL ();
 391
 392   /* In this case the format string is not known at compile time,
 393      but resides in read-only memory, so is ok.  */
 394   if (printf (str3, str4, &n1, str5, &n2) != 14
 395       || n1 != 7 || n2 != 14)
 396     FAIL ();
 397
 398   strcpy (buf2 + 2, "%n%s%n");
 399   /* When the format string is writable and contains %n,
 400      with -D_FORTIFY_SOURCE=2 it causes __chk_fail.  */
 401   CHK_FAIL2_START
 402   if (printf (buf2, str4, &n1, str5, &n1) != 14)
 403     FAIL ();
 404   CHK_FAIL2_END
 405
 406   /* But if there is no %n, even writable format string
 407      should work.  */
 408   buf2[6] = '\0';
 409   if (printf (buf2 + 4, str5) != 7)
 410     FAIL ();
 411
 412   FILE *fp = stdout;
 413
 414   /* Constant literals passed directly are always ok
 415      (even with warnings about possible bugs from GCC).  */
 416   if (fprintf (fp, "%s%n%s%n", str4, &n1, str5, &n2) != 14
 417       || n1 != 7 || n2 != 14)
 418     FAIL ();
 419
 420   /* In this case the format string is not known at compile time,
 421      but resides in read-only memory, so is ok.  */
 422   if (fprintf (fp, str3, str4, &n1, str5, &n2) != 14
 423       || n1 != 7 || n2 != 14)
 424     FAIL ();
 425
 426   strcpy (buf2 + 2, "%n%s%n");
 427   /* When the format string is writable and contains %n,
 428      with -D_FORTIFY_SOURCE=2 it causes __chk_fail.  */
 429   CHK_FAIL2_START
 430   if (fprintf (fp, buf2, str4, &n1, str5, &n1) != 14)
 431     FAIL ();
 432   CHK_FAIL2_END
 433
 434   /* But if there is no %n, even writable format string
 435      should work.  */
 436   buf2[6] = '\0';
 437   if (fprintf (fp, buf2 + 4, str5) != 7)
 438     FAIL ();
 439
 440   if (freopen (temp_filename, "r", stdin) == NULL)
 441     {
 442       puts ("could not open temporary file");
 443       exit (1);
 444     }
 445
 446   if (gets (buf) != buf || memcmp (buf, "abcdefgh", 9))
 447     FAIL ();
 448   if (gets (buf) != buf || memcmp (buf, "ABCDEFGHI", 10))
 449     FAIL ();
 450
 451 #if __USE_FORTIFY_LEVEL >= 1
 452   CHK_FAIL_START
 453   if (gets (buf) != buf)
 454     FAIL ();
 455   CHK_FAIL_END
 456 #endif
 457
 458   if (freopen (temp_filename, "r", stdin) == NULL)
 459     {
 460       puts ("could not open temporary file");
 461       exit (1);
 462     }
 463
 464   if (fseek (stdin, 9 + 10 + 11, SEEK_SET))
 465     {
 466       puts ("could not seek in test file");
 467       exit (1);
 468     }
 469
 470 #if __USE_FORTIFY_LEVEL >= 1
 471   CHK_FAIL_START
 472   if (gets (buf) != buf)
 473     FAIL ();
 474   CHK_FAIL_END
 475 #endif
 476
 477   /* Check whether missing N$ formats are detected.  */
 478   CHK_FAIL2_START
 479   printf ("%3$d\n", 1, 2, 3, 4);
 480   CHK_FAIL2_END
 481
 482   CHK_FAIL2_START
 483   fprintf (stdout, "%3$d\n", 1, 2, 3, 4);
 484   CHK_FAIL2_END
 485
 486   CHK_FAIL2_START
 487   sprintf (buf, "%3$d\n", 1, 2, 3, 4);
 488   CHK_FAIL2_END
 489
 490   CHK_FAIL2_START
 491   snprintf (buf, sizeof (buf), "%3$d\n", 1, 2, 3, 4);
 492   CHK_FAIL2_END
 493
 494   return ret;
 495 }