nptl/tst-setuid2.c

   1 /* Copyright (C) 2014-2021 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 #include <errno.h>
  19 #include <pthread.h>
  20 #include <signal.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <sys/syscall.h>
  24 #include <unistd.h>
  25
  26 /* Check that a partial setuid failure aborts the process. */
  27
  28 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  29 static pthread_cond_t cond_send;
  30 static void (*func_sent) (void);
  31 static pthread_cond_t cond_recv;
  32
  33 #define FAIL(fmt, ...) \
  34   do { printf ("FAIL: " fmt "\n", __VA_ARGS__); _exit (1); } while (0)
  35
  36 static void *
  37 thread_func (void *ctx __attribute__ ((unused)))
  38 {
  39   int ret = pthread_mutex_lock (&mutex);
  40   if (ret != 0)
  41     FAIL ("pthread_mutex_lock (thread): %d", ret);
  42
  43   while (true)
  44     {
  45       if (func_sent != NULL)
  46         {
  47           void (*func) (void) = func_sent;
  48           ret = pthread_mutex_unlock (&mutex);
  49           if (ret != 0)
  50             FAIL ("pthread_mutex_unlock (thread): %d", ret);
  51           func ();
  52           ret = pthread_mutex_lock (&mutex);
  53           if (ret != 0)
  54             FAIL ("pthread_mutex_lock (thread): %d", ret);
  55           func_sent = NULL;
  56           ret = pthread_cond_signal (&cond_recv);
  57           if (ret != 0)
  58             FAIL ("pthread_cond_signal (recv): %d", ret);
  59         }
  60       ret = pthread_cond_wait (&cond_send, &mutex);
  61       if (ret != 0)
  62         FAIL ("pthread_cond_wait (send): %d", ret);
  63     }
  64   return NULL;
  65 }
  66
  67 static void
  68 run_on_thread (void (*func) (void))
  69 {
  70   int ret = pthread_mutex_lock (&mutex);
  71   if (ret != 0)
  72     FAIL ("pthread_mutex_lock (%s): %d", __func__, ret);
  73   func_sent = func;
  74   ret = pthread_mutex_unlock (&mutex);
  75   if (ret != 0)
  76     FAIL ("pthread_mutex_unlock (%s): %d", __func__, ret);
  77
  78   ret = pthread_cond_signal (&cond_send);
  79   if (ret != 0)
  80     FAIL ("pthread_mutex_lock (%s): %d", __func__, ret);
  81
  82   ret = pthread_mutex_lock (&mutex);
  83   if (ret != 0)
  84     FAIL ("pthread_mutex_lock (%s): %d", __func__, ret);
  85
  86   while (func_sent != NULL)
  87     {
  88       ret = pthread_cond_wait (&cond_recv, &mutex);
  89       if (ret != 0)
  90         FAIL ("pthread_mutex_wait (%s): %d", __func__, ret);
  91     }
  92   ret = pthread_mutex_unlock (&mutex);
  93   if (ret != 0)
  94     FAIL ("pthread_mutex_unlock (%s): %d", __func__, ret);
  95 }
  96
  97 static void
  98 change_thread_ids (void)
  99 {
 100   long ret = syscall (__NR_setresuid, 2001, 2002, 2003);
 101   if (ret != 0)
 102     FAIL ("setresuid (2001, 2002, 2003): %ld", ret);
 103 }
 104
 105 static uid_t ruid, euid, suid;
 106
 107 static void
 108 get_thread_ids (void)
 109 {
 110   if (getresuid (&ruid, &euid, &suid) < 0)
 111     FAIL ("getresuid: %m (%d)", errno);
 112 }
 113
 114 static void
 115 abort_expected (int signal __attribute__ ((unused)))
 116 {
 117   _exit (0);
 118 }
 119
 120 static int
 121 do_test (void)
 122 {
 123   pthread_t thread;
 124   int ret = pthread_create (&thread, NULL, thread_func, NULL);
 125   if (ret != 0)
 126     FAIL ("pthread_create: %d", ret);
 127
 128   run_on_thread (change_thread_ids);
 129
 130   signal (SIGABRT, &abort_expected);
 131   /* This should abort the process.  */
 132   if (setresuid (1001, 1002, 1003) < 0)
 133     FAIL ("setresuid: %m (%d)", errno);
 134   signal (SIGABRT, SIG_DFL);
 135
 136   /* If we get here, check that the kernel did the right thing. */
 137   run_on_thread (get_thread_ids);
 138   if (ruid != 1001 || euid != 1002 || suid != 1003)
 139     FAIL ("unexpected UIDs after setuid: %ld, %ld, %ld",
 140           (long) ruid, (long) euid, (long) suid);
 141   return 0;
 142 }
 143
 144 #define TEST_FUNCTION do_test ()
 145 #include "../test-skeleton.c"