elf/tst-env-setuid-tunables.c

   1 /* Copyright (C) 2017-2024 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 /* Verify that GLIBC_TUNABLES is kept unchanged but no tunable is actually
  19    enabled for AT_SECURE processes.  */
  20
  21 #include <dl-tunables.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <stdlib.h>
  25 #include <stdint.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <sys/stat.h>
  29 #include <sys/wait.h>
  30 #include <unistd.h>
  31 #include <intprops.h>
  32 #include <array_length.h>
  33
  34 #include <support/check.h>
  35 #include <support/support.h>
  36 #include <support/test-driver.h>
  37 #include <support/capture_subprocess.h>
  38
  39 static const char *teststrings[] =
  40 {
  41   "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
  42   "glibc.malloc.check=2:glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096",
  43   "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2",
  44   "glibc.malloc.perturb=0x800",
  45   "glibc.malloc.perturb=0x800:glibc.malloc.mmap_threshold=4096",
  46   "glibc.malloc.perturb=0x800:not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096",
  47   "glibc.not_valid.check=2:glibc.malloc.mmap_threshold=4096",
  48   "not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096",
  49   "glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096",
  50   "glibc.malloc.check=2",
  51   "glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096:glibc.malloc.check=2",
  52   "glibc.malloc.check=4:glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096",
  53   ":glibc.malloc.garbage=2:glibc.malloc.check=1",
  54   "glibc.malloc.check=1:glibc.malloc.check=2",
  55   "not_valid.malloc.check=2",
  56   "glibc.not_valid.check=2",
  57 };
  58
  59 static int
  60 test_child (int off)
  61 {
  62   const char *val = getenv ("GLIBC_TUNABLES");
  63   int ret = 1;
  64
  65   printf ("    [%d] GLIBC_TUNABLES is %s\n", off, val);
  66   fflush (stdout);
  67   if (val != NULL)
  68     printf ("    [%d] Unexpected GLIBC_TUNABLES VALUE %s\n", off, val);
  69   else
  70     ret = 0;
  71   fflush (stdout);
  72
  73   /* Also check if the set tunables are effectively unchanged.  */
  74   int32_t check = TUNABLE_GET_FULL (glibc, malloc, check, int32_t, NULL);
  75   size_t mmap_threshold = TUNABLE_GET_FULL (glibc, malloc, mmap_threshold,
  76                                             size_t, NULL);
  77   int32_t perturb = TUNABLE_GET_FULL (glibc, malloc, perturb, int32_t, NULL);
  78
  79   printf ("    [%d] glibc.malloc.check=%d\n", off, check);
  80   fflush (stdout);
  81   printf ("    [%d] glibc.malloc.mmap_threshold=%zu\n", off, mmap_threshold);
  82   fflush (stdout);
  83   printf ("    [%d] glibc.malloc.perturb=%d\n", off, perturb);
  84   fflush (stdout);
  85
  86   ret |= check != 0;
  87   ret |= mmap_threshold != 0;
  88   ret |= perturb != 0;
  89
  90   return ret;
  91 }
  92
  93 static int
  94 do_test (int argc, char **argv)
  95 {
  96   /* Setgid child process.  */
  97   if (argc == 2)
  98     {
  99       if (getgid () == getegid ())
 100         /* This can happen if the file system is mounted nosuid.  */
 101         FAIL_UNSUPPORTED ("SGID failed: GID and EGID match (%jd)\n",
 102                           (intmax_t) getgid ());
 103
 104       int ret = test_child (atoi (argv[1]));
 105
 106       if (ret != 0)
 107         exit (1);
 108
 109       /* Special return code to make sure that the child executed all the way
 110          through.  */
 111       exit (42);
 112     }
 113   else
 114     {
 115       /* Spawn tests.  */
 116       for (int i = 0; i < array_length (teststrings); i++)
 117         {
 118           char buf[INT_BUFSIZE_BOUND (int)];
 119
 120           printf ("[%d] Spawned test for %s\n", i, teststrings[i]);
 121           snprintf (buf, sizeof (buf), "%d\n", i);
 122           fflush (stdout);
 123           if (setenv ("GLIBC_TUNABLES", teststrings[i], 1) != 0)
 124             {
 125               printf ("    [%d] Failed to set GLIBC_TUNABLES: %m", i);
 126               support_record_failure ();
 127               continue;
 128             }
 129
 130           int status = support_capture_subprogram_self_sgid (buf);
 131
 132           /* Bail out early if unsupported.  */
 133           if (WEXITSTATUS (status) == EXIT_UNSUPPORTED)
 134             return EXIT_UNSUPPORTED;
 135
 136           if (WEXITSTATUS (status) != 42)
 137             {
 138               printf ("    [%d] child failed with status %d\n", i,
 139                       WEXITSTATUS (status));
 140               support_record_failure ();
 141             }
 142         }
 143       return 0;
 144     }
 145 }
 146
 147 #define TEST_FUNCTION_ARGV do_test
 148 #include <support/test-driver.c>