1 /* Copyright (C) 2014-2022 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 <stdio.h>
19 #include <errno.h>
20 #include <pthread.h>
21 #include <stdbool.h>
22 #include <unistd.h>
23 
24 /* The test must run under a non-privileged user ID.  */
25 static const uid_t test_uid = 1;
26 
27 static pthread_barrier_t barrier1;
28 static pthread_barrier_t barrier2;
29 
30 #define FAIL(fmt, ...) \
31   do { printf ("FAIL: " fmt "\n", __VA_ARGS__); _exit (1); } while (0)
32 
33 #define FAIL_ERR(fmt, ...) \
34   do { printf ("FAIL: " fmt ": %m\n", __VA_ARGS__); _exit (1); } while (0)
35 
36 /* True if x is not a successful return code from pthread_barrier_wait.  */
37 static inline bool
is_invalid_barrier_ret(int x)38 is_invalid_barrier_ret (int x)
39 {
40   return x != 0 && x != PTHREAD_BARRIER_SERIAL_THREAD;
41 }
42 
43 static void *
thread_func(void * ctx)44 thread_func (void *ctx __attribute__ ((unused)))
45 {
46   int ret = pthread_barrier_wait (&barrier1);
47   if (is_invalid_barrier_ret (ret))
48     FAIL ("pthread_barrier_wait (barrier1) (on thread): %d", ret);
49   ret = pthread_barrier_wait (&barrier2);
50   if (is_invalid_barrier_ret (ret))
51     FAIL ("pthread_barrier_wait (barrier2) (on thread): %d", ret);
52   return NULL;
53 }
54 
55 static void
setuid_failure(int phase)56 setuid_failure (int phase)
57 {
58   int ret = setuid (0);
59   switch (ret)
60     {
61     case 0:
62       FAIL ("setuid succeeded unexpectedly in phase %d", phase);
63     case -1:
64       if (errno != EPERM)
65 	FAIL_ERR ("setuid phase %d", phase);
66       break;
67     default:
68       FAIL ("invalid setuid return value in phase %d: %d", phase, ret);
69     }
70 }
71 
72 static int
do_test(void)73 do_test (void)
74 {
75   if (getuid () == 0)
76     if (setuid (test_uid) != 0)
77       FAIL_ERR ("setuid (%u)", (unsigned) test_uid);
78   if (setuid (getuid ()))
79     FAIL_ERR ("setuid (%s)", "getuid ()");
80   setuid_failure (1);
81 
82   int ret = pthread_barrier_init (&barrier1, NULL, 2);
83   if (ret != 0)
84     FAIL ("pthread_barrier_init (barrier1): %d", ret);
85   ret = pthread_barrier_init (&barrier2, NULL, 2);
86   if (ret != 0)
87     FAIL ("pthread_barrier_init (barrier2): %d", ret);
88 
89   pthread_t thread;
90   ret = pthread_create (&thread, NULL, thread_func, NULL);
91   if (ret != 0)
92     FAIL ("pthread_create: %d", ret);
93 
94   /* Ensure that the thread is running properly.  */
95   ret = pthread_barrier_wait (&barrier1);
96   if (is_invalid_barrier_ret (ret))
97     FAIL ("pthread_barrier_wait (barrier1): %d", ret);
98 
99   setuid_failure (2);
100 
101   /* Check success case. */
102   if (setuid (getuid ()) != 0)
103     FAIL_ERR ("setuid (%s)", "getuid ()");
104 
105   /* Shutdown.  */
106   ret = pthread_barrier_wait (&barrier2);
107   if (is_invalid_barrier_ret (ret))
108     FAIL ("pthread_barrier_wait (barrier2): %d", ret);
109 
110   ret = pthread_join (thread, NULL);
111   if (ret != 0)
112     FAIL ("pthread_join: %d", ret);
113 
114   return 0;
115 }
116 
117 #define TEST_FUNCTION do_test ()
118 #include "../test-skeleton.c"
119