1 /*
2 * Copyright (c) 2014-2016 Dmitry V. Levin <ldv@altlinux.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include "tests.h"
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33
34 int
read_int_from_file(const char * const fname,int * const pvalue)35 read_int_from_file(const char *const fname, int *const pvalue)
36 {
37 const int fd = open(fname, O_RDONLY);
38 if (fd < 0)
39 return -1;
40
41 long lval;
42 char buf[sizeof(lval) * 3];
43 int n = read(fd, buf, sizeof(buf) - 1);
44 int saved_errno = errno;
45 close(fd);
46
47 if (n < 0) {
48 errno = saved_errno;
49 return -1;
50 }
51
52 buf[n] = '\0';
53 char *endptr = 0;
54 errno = 0;
55 lval = strtol(buf, &endptr, 10);
56 if (!endptr || (*endptr && '\n' != *endptr)
57 #if INT_MAX < LONG_MAX
58 || lval > INT_MAX || lval < INT_MIN
59 #endif
60 || ERANGE == errno) {
61 if (!errno)
62 errno = EINVAL;
63 return -1;
64 }
65
66 *pvalue = (int) lval;
67 return 0;
68 }
69
70 static void
check_overflow_id(const int id,const char * overflowid)71 check_overflow_id(const int id, const char *overflowid)
72 {
73 int n;
74
75 if (read_int_from_file(overflowid, &n)) {
76 if (ENOENT == errno)
77 return;
78 perror_msg_and_fail("read_int_from_file: %s", overflowid);
79 }
80
81 if (id == n)
82 error_msg_and_skip("%d matches %s", id, overflowid);
83 }
84
85 void
check_overflowuid(const int uid)86 check_overflowuid(const int uid)
87 {
88 check_overflow_id(uid, "/proc/sys/kernel/overflowuid");
89 }
90
91 void
check_overflowgid(const int gid)92 check_overflowgid(const int gid)
93 {
94 check_overflow_id(gid, "/proc/sys/kernel/overflowgid");
95 }
96