nptl/tst-setuid2.c

   1 /* Copyright (C) 2014-2024 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 #include <errno.h>
  19 #include <pthread.h>
  20 #include <signal.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <support/xthread.h>
  24 #include <sys/syscall.h>
  25 #include <unistd.h>
  26
  27 /* Check that a partial setuid failure aborts the process. */
  28
  29 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
  30 static pthread_cond_t cond_send;
  31 static void (*func_sent) (void);
  32 static pthread_cond_t cond_recv;
  33
  34 #define FAIL(fmt, ...) \
  35   do { printf ("FAIL: " fmt "\n", __VA_ARGS__); _exit (1); } while (0)
  36
  37 static void *
  38 thread_func (void *ctx __attribute__ ((unused)))
  39 {
  40   xpthread_mutex_lock (&mutex);
  41   while (true)
  42     {
  43       if (func_sent != NULL)
  44         {
  45           void (*func) (void) = func_sent;
  46           xpthread_mutex_unlock (&mutex);
  47
  48           func ();
  49
  50           xpthread_mutex_lock (&mutex);
  51           func_sent = NULL;
  52           xpthread_cond_signal (&cond_recv);
  53         }
  54       xpthread_cond_wait (&cond_send, &mutex);
  55     }
  56   return NULL;
  57 }
  58
  59 static void
  60 run_on_thread (void (*func) (void))
  61 {
  62   xpthread_mutex_lock (&mutex);
  63   func_sent = func;
  64   xpthread_mutex_unlock (&mutex);
  65
  66   xpthread_cond_signal (&cond_send);
  67
  68   xpthread_mutex_lock (&mutex);
  69   while (func_sent != NULL)
  70     {
  71       xpthread_cond_wait (&cond_recv, &mutex);
  72     }
  73   xpthread_mutex_unlock (&mutex);
  74 }
  75
  76 static void
  77 change_thread_ids (void)
  78 {
  79   long ret = syscall (__NR_setresuid, 2001, 2002, 2003);
  80   if (ret != 0)
  81     FAIL ("setresuid (2001, 2002, 2003): %ld", ret);
  82 }
  83
  84 static uid_t ruid, euid, suid;
  85
  86 static void
  87 get_thread_ids (void)
  88 {
  89   if (getresuid (&ruid, &euid, &suid) < 0)
  90     FAIL ("getresuid: %m (%d)", errno);
  91 }
  92
  93 static void
  94 abort_expected (int signal __attribute__ ((unused)))
  95 {
  96   _exit (0);
  97 }
  98
  99 static int
 100 do_test (void)
 101 {
 102   pthread_t thread;
 103   int ret = pthread_create (&thread, NULL, thread_func, NULL);
 104   if (ret != 0)
 105     FAIL ("pthread_create: %d", ret);
 106
 107   run_on_thread (change_thread_ids);
 108
 109   signal (SIGABRT, &abort_expected);
 110   /* This should abort the process.  */
 111   if (setresuid (1001, 1002, 1003) < 0)
 112     FAIL ("setresuid: %m (%d)", errno);
 113   signal (SIGABRT, SIG_DFL);
 114
 115   /* If we get here, check that the kernel did the right thing. */
 116   run_on_thread (get_thread_ids);
 117   if (ruid != 1001 || euid != 1002 || suid != 1003)
 118     FAIL ("unexpected UIDs after setuid: %ld, %ld, %ld",
 119           (long) ruid, (long) euid, (long) suid);
 120   return 0;
 121 }
 122
 123 #include <support/test-driver.c>