1 /*
2 * Check decoding of chown/chown32/lchown/lchown32/fchown/fchown32 syscalls.
3 *
4 * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <fcntl.h>
31 #include <stdio.h>
32 #include <unistd.h>
33
34 #ifdef UGID_TYPE_IS_SHORT
35 # define UGID_TYPE short
36 # define GETEUID syscall(__NR_geteuid)
37 # define GETEGID syscall(__NR_getegid)
38 # define CHECK_OVERFLOWUID(arg) check_overflowuid(arg)
39 # define CHECK_OVERFLOWGID(arg) check_overflowgid(arg)
40 #else
41 # define UGID_TYPE int
42 # define GETEUID geteuid()
43 # define GETEGID getegid()
44 # define CHECK_OVERFLOWUID(arg)
45 # define CHECK_OVERFLOWGID(arg)
46 #endif
47
48 #define UNLINK_SAMPLE \
49 if (unlink(sample)) perror_msg_and_fail("unlink")
50 #define CLOSE_SAMPLE \
51 if (close(fd)) perror_msg_and_fail("close")
52
53 #ifdef ACCESS_BY_DESCRIPTOR
54 # define SYSCALL_ARG1 fd
55 # define FMT_ARG1 "%d"
56 # define EOK_CMD CLOSE_SAMPLE
57 # define CLEANUP_CMD UNLINK_SAMPLE
58 #else
59 # define SYSCALL_ARG1 sample
60 # define FMT_ARG1 "\"%s\""
61 # define EOK_CMD UNLINK_SAMPLE
62 # define CLEANUP_CMD CLOSE_SAMPLE
63 #endif
64
65 static int
ugid2int(const unsigned UGID_TYPE id)66 ugid2int(const unsigned UGID_TYPE id)
67 {
68 if ((unsigned UGID_TYPE) -1U == id)
69 return -1;
70 else
71 return id;
72 }
73
74 static void
print_int(const unsigned int num)75 print_int(const unsigned int num)
76 {
77 if (num == -1U)
78 printf(", -1");
79 else
80 printf(", %u", num);
81 }
82
83 static int
num_matches_id(const unsigned int num,const unsigned int id)84 num_matches_id(const unsigned int num, const unsigned int id)
85 {
86 return num == id || num == -1U;
87 }
88
89 #define PAIR(val) { val, gid }, { uid, val }
90
91 int
main(void)92 main(void)
93 {
94 static const char sample[] = SYSCALL_NAME "_sample";
95
96 unsigned int uid = GETEUID;
97 CHECK_OVERFLOWUID(uid);
98 unsigned int gid = GETEGID;
99 CHECK_OVERFLOWUID(gid);
100
101 const struct {
102 const long uid, gid;
103 } tests[] = {
104 { uid, gid },
105 { (unsigned long) 0xffffffff00000000ULL | uid, gid },
106 { uid, (unsigned long) 0xffffffff00000000ULL | gid },
107 PAIR(-1U),
108 PAIR(-1L),
109 { 0xffff0000U | uid, gid },
110 { uid, 0xffff0000U | gid },
111 PAIR(0xffff),
112 PAIR(0xc0deffffU),
113 PAIR(0xfacefeedU),
114 PAIR((long) 0xfacefeeddeadbeefULL)
115 };
116
117 int fd = open(sample, O_RDONLY | O_CREAT, 0400);
118 if (fd < 0)
119 perror_msg_and_fail("open");
120
121 CLEANUP_CMD;
122
123 unsigned int i;
124 long expected = 0;
125
126 for (i = 0; i < ARRAY_SIZE(tests); ++i) {
127 const unsigned int unum = ugid2int(tests[i].uid);
128 const unsigned int gnum = ugid2int(tests[i].gid);
129
130 if (num_matches_id(unum, uid) &&
131 num_matches_id(gnum, gid)) {
132 if (expected)
133 continue;
134 } else {
135 if (!expected) {
136 expected = -1;
137 EOK_CMD;
138 }
139 }
140
141 const long rc = syscall(SYSCALL_NR, SYSCALL_ARG1,
142 tests[i].uid, tests[i].gid);
143 const char *errstr = sprintrc(rc);
144 printf("%s(" FMT_ARG1, SYSCALL_NAME, SYSCALL_ARG1);
145 print_int(unum);
146 print_int(gnum);
147 printf(") = %s\n", errstr);
148 }
149
150 puts("+++ exited with 0 +++");
151 return 0;
152 }
153