elf/tst-ldconfig-bad-aux-cache.c

   1 /* Test ldconfig does not segfault when aux-cache is corrupted (Bug 18093).
   2    Copyright (C) 2019-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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; see the file COPYING.LIB.  If
  17    not, see <https://www.gnu.org/licenses/>.  */
  18
  19 /* This test does the following:
  20    Run ldconfig to create the caches.
  21    Corrupt the caches.
  22    Run ldconfig again.
  23    At each step we verify that ldconfig does not crash.  */
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <sys/wait.h>
  31 #include <ftw.h>
  32 #include <stdint.h>
  33
  34 #include <support/capture_subprocess.h>
  35 #include <support/check.h>
  36 #include <support/support.h>
  37 #include <support/xunistd.h>
  38
  39 #include <dirent.h>
  40
  41 static int
  42 display_info (const char *fpath, const struct stat *sb,
  43               int tflag, struct FTW *ftwbuf)
  44 {
  45   printf ("info: %-3s %2d %7jd   %-40s %d %s\n",
  46           (tflag == FTW_D) ? "d" : (tflag == FTW_DNR) ? "dnr" :
  47           (tflag == FTW_DP) ? "dp" : (tflag == FTW_F) ? "f" :
  48           (tflag == FTW_NS) ? "ns" : (tflag == FTW_SL) ? "sl" :
  49           (tflag == FTW_SLN) ? "sln" : "???",
  50           ftwbuf->level, (intmax_t) sb->st_size,
  51           fpath, ftwbuf->base, fpath + ftwbuf->base);
  52   /* To tell nftw to continue.  */
  53   return 0;
  54 }
  55
  56 static void
  57 execv_wrapper (void *args)
  58 {
  59   char **argv = args;
  60
  61   execv (argv[0], argv);
  62   FAIL_EXIT1 ("execv: %m");
  63 }
  64
  65 /* Run ldconfig with a corrupt aux-cache, in particular we test for size
  66    truncation that might happen if a previous ldconfig run failed or if
  67    there were storage or power issues while we were writing the file.
  68    We want ldconfig not to crash, and it should be able to do so by
  69    computing the expected size of the file (bug 18093).  */
  70 static int
  71 do_test (void)
  72 {
  73   char *prog = xasprintf ("%s/ldconfig", support_install_rootsbindir);
  74   char *args[] = { prog, NULL };
  75   const char *path = "/var/cache/ldconfig/aux-cache";
  76   struct stat64 fs;
  77   long int size, new_size, i;
  78
  79   /* Create the needed directories. */
  80   xmkdirp ("/var/cache/ldconfig", 0777);
  81
  82   /* Run ldconfig first to generate the aux-cache.  */
  83   struct support_capture_subprocess result;
  84   result = support_capture_subprocess (execv_wrapper, args);
  85   support_capture_subprocess_check (&result, "execv", 0, sc_allow_none);
  86   support_capture_subprocess_free (&result);
  87
  88   xstat (path, &fs);
  89
  90   size = fs.st_size;
  91   /* Run 3 tests, each truncating aux-cache shorter and shorter.  */
  92   for (i = 3; i > 0; i--)
  93     {
  94       new_size = size * i / 4;
  95       if (truncate (path, new_size))
  96         FAIL_EXIT1 ("truncation failed: %m");
  97       if (nftw (path, display_info, 1000, 0) == -1)
  98         FAIL_EXIT1 ("nftw failed.");
  99
 100       /* Verify that ldconfig can run with a truncated
 101          aux-cache and doesn't crash.  */
 102       struct support_capture_subprocess result;
 103       result = support_capture_subprocess (execv_wrapper, args);
 104       support_capture_subprocess_check (&result, "execv", 0, sc_allow_none);
 105       support_capture_subprocess_free (&result);
 106     }
 107
 108   free (prog);
 109   return 0;
 110 }
 111
 112 #include <support/test-driver.c>