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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Landlock tests - Common user space base
4 *
5 * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
6 * Copyright © 2019-2020 ANSSI
7 */
8
9#define _GNU_SOURCE
10#include <errno.h>
11#include <fcntl.h>
12#include <linux/landlock.h>
13#include <string.h>
14#include <sys/prctl.h>
15#include <sys/socket.h>
16#include <sys/types.h>
17
18#include "common.h"
19
20#ifndef O_PATH
21#define O_PATH 010000000
22#endif
23
24TEST(inconsistent_attr)
25{
26 const long page_size = sysconf(_SC_PAGESIZE);
27 char *const buf = malloc(page_size + 1);
28 struct landlock_ruleset_attr *const ruleset_attr = (void *)buf;
29
30 ASSERT_NE(NULL, buf);
31
32 /* Checks copy_from_user(). */
33 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 0, 0));
34 /* The size if less than sizeof(struct landlock_attr_enforce). */
35 ASSERT_EQ(EINVAL, errno);
36 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 1, 0));
37 ASSERT_EQ(EINVAL, errno);
38 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 7, 0));
39 ASSERT_EQ(EINVAL, errno);
40
41 ASSERT_EQ(-1, landlock_create_ruleset(NULL, 1, 0));
42 /* The size if less than sizeof(struct landlock_attr_enforce). */
43 ASSERT_EQ(EFAULT, errno);
44
45 ASSERT_EQ(-1, landlock_create_ruleset(
46 NULL, sizeof(struct landlock_ruleset_attr), 0));
47 ASSERT_EQ(EFAULT, errno);
48
49 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0));
50 ASSERT_EQ(E2BIG, errno);
51
52 /* Checks minimal valid attribute size. */
53 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 8, 0));
54 ASSERT_EQ(ENOMSG, errno);
55 ASSERT_EQ(-1, landlock_create_ruleset(
56 ruleset_attr,
57 sizeof(struct landlock_ruleset_attr), 0));
58 ASSERT_EQ(ENOMSG, errno);
59 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0));
60 ASSERT_EQ(ENOMSG, errno);
61
62 /* Checks non-zero value. */
63 buf[page_size - 2] = '.';
64 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0));
65 ASSERT_EQ(E2BIG, errno);
66
67 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0));
68 ASSERT_EQ(E2BIG, errno);
69
70 free(buf);
71}
72
73TEST(abi_version)
74{
75 const struct landlock_ruleset_attr ruleset_attr = {
76 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
77 };
78 ASSERT_EQ(3, landlock_create_ruleset(NULL, 0,
79 LANDLOCK_CREATE_RULESET_VERSION));
80
81 ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0,
82 LANDLOCK_CREATE_RULESET_VERSION));
83 ASSERT_EQ(EINVAL, errno);
84
85 ASSERT_EQ(-1, landlock_create_ruleset(NULL, sizeof(ruleset_attr),
86 LANDLOCK_CREATE_RULESET_VERSION));
87 ASSERT_EQ(EINVAL, errno);
88
89 ASSERT_EQ(-1,
90 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr),
91 LANDLOCK_CREATE_RULESET_VERSION));
92 ASSERT_EQ(EINVAL, errno);
93
94 ASSERT_EQ(-1, landlock_create_ruleset(NULL, 0,
95 LANDLOCK_CREATE_RULESET_VERSION |
96 1 << 31));
97 ASSERT_EQ(EINVAL, errno);
98}
99
100/* Tests ordering of syscall argument checks. */
101TEST(create_ruleset_checks_ordering)
102{
103 const int last_flag = LANDLOCK_CREATE_RULESET_VERSION;
104 const int invalid_flag = last_flag << 1;
105 int ruleset_fd;
106 const struct landlock_ruleset_attr ruleset_attr = {
107 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
108 };
109
110 /* Checks priority for invalid flags. */
111 ASSERT_EQ(-1, landlock_create_ruleset(NULL, 0, invalid_flag));
112 ASSERT_EQ(EINVAL, errno);
113
114 ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0, invalid_flag));
115 ASSERT_EQ(EINVAL, errno);
116
117 ASSERT_EQ(-1, landlock_create_ruleset(NULL, sizeof(ruleset_attr),
118 invalid_flag));
119 ASSERT_EQ(EINVAL, errno);
120
121 ASSERT_EQ(-1,
122 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr),
123 invalid_flag));
124 ASSERT_EQ(EINVAL, errno);
125
126 /* Checks too big ruleset_attr size. */
127 ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, -1, 0));
128 ASSERT_EQ(E2BIG, errno);
129
130 /* Checks too small ruleset_attr size. */
131 ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0, 0));
132 ASSERT_EQ(EINVAL, errno);
133 ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 1, 0));
134 ASSERT_EQ(EINVAL, errno);
135
136 /* Checks valid call. */
137 ruleset_fd =
138 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
139 ASSERT_LE(0, ruleset_fd);
140 ASSERT_EQ(0, close(ruleset_fd));
141}
142
143/* Tests ordering of syscall argument checks. */
144TEST(add_rule_checks_ordering)
145{
146 const struct landlock_ruleset_attr ruleset_attr = {
147 .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
148 };
149 struct landlock_path_beneath_attr path_beneath_attr = {
150 .allowed_access = LANDLOCK_ACCESS_FS_EXECUTE,
151 .parent_fd = -1,
152 };
153 const int ruleset_fd =
154 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
155
156 ASSERT_LE(0, ruleset_fd);
157
158 /* Checks invalid flags. */
159 ASSERT_EQ(-1, landlock_add_rule(-1, 0, NULL, 1));
160 ASSERT_EQ(EINVAL, errno);
161
162 /* Checks invalid ruleset FD. */
163 ASSERT_EQ(-1, landlock_add_rule(-1, 0, NULL, 0));
164 ASSERT_EQ(EBADF, errno);
165
166 /* Checks invalid rule type. */
167 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, 0, NULL, 0));
168 ASSERT_EQ(EINVAL, errno);
169
170 /* Checks invalid rule attr. */
171 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
172 NULL, 0));
173 ASSERT_EQ(EFAULT, errno);
174
175 /* Checks invalid path_beneath.parent_fd. */
176 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
177 &path_beneath_attr, 0));
178 ASSERT_EQ(EBADF, errno);
179
180 /* Checks valid call. */
181 path_beneath_attr.parent_fd =
182 open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
183 ASSERT_LE(0, path_beneath_attr.parent_fd);
184 ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
185 &path_beneath_attr, 0));
186 ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
187 ASSERT_EQ(0, close(ruleset_fd));
188}
189
190/* Tests ordering of syscall argument and permission checks. */
191TEST(restrict_self_checks_ordering)
192{
193 const struct landlock_ruleset_attr ruleset_attr = {
194 .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
195 };
196 struct landlock_path_beneath_attr path_beneath_attr = {
197 .allowed_access = LANDLOCK_ACCESS_FS_EXECUTE,
198 .parent_fd = -1,
199 };
200 const int ruleset_fd =
201 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
202
203 ASSERT_LE(0, ruleset_fd);
204 path_beneath_attr.parent_fd =
205 open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
206 ASSERT_LE(0, path_beneath_attr.parent_fd);
207 ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
208 &path_beneath_attr, 0));
209 ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
210
211 /* Checks unprivileged enforcement without no_new_privs. */
212 drop_caps(_metadata);
213 ASSERT_EQ(-1, landlock_restrict_self(-1, -1));
214 ASSERT_EQ(EPERM, errno);
215 ASSERT_EQ(-1, landlock_restrict_self(-1, 0));
216 ASSERT_EQ(EPERM, errno);
217 ASSERT_EQ(-1, landlock_restrict_self(ruleset_fd, 0));
218 ASSERT_EQ(EPERM, errno);
219
220 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
221
222 /* Checks invalid flags. */
223 ASSERT_EQ(-1, landlock_restrict_self(-1, -1));
224 ASSERT_EQ(EINVAL, errno);
225
226 /* Checks invalid ruleset FD. */
227 ASSERT_EQ(-1, landlock_restrict_self(-1, 0));
228 ASSERT_EQ(EBADF, errno);
229
230 /* Checks valid call. */
231 ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
232 ASSERT_EQ(0, close(ruleset_fd));
233}
234
235TEST(ruleset_fd_io)
236{
237 struct landlock_ruleset_attr ruleset_attr = {
238 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
239 };
240 int ruleset_fd;
241 char buf;
242
243 drop_caps(_metadata);
244 ruleset_fd =
245 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
246 ASSERT_LE(0, ruleset_fd);
247
248 ASSERT_EQ(-1, write(ruleset_fd, ".", 1));
249 ASSERT_EQ(EINVAL, errno);
250 ASSERT_EQ(-1, read(ruleset_fd, &buf, 1));
251 ASSERT_EQ(EINVAL, errno);
252
253 ASSERT_EQ(0, close(ruleset_fd));
254}
255
256/* Tests enforcement of a ruleset FD transferred through a UNIX socket. */
257TEST(ruleset_fd_transfer)
258{
259 struct landlock_ruleset_attr ruleset_attr = {
260 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR,
261 };
262 struct landlock_path_beneath_attr path_beneath_attr = {
263 .allowed_access = LANDLOCK_ACCESS_FS_READ_DIR,
264 };
265 int ruleset_fd_tx, dir_fd;
266 int socket_fds[2];
267 pid_t child;
268 int status;
269
270 drop_caps(_metadata);
271
272 /* Creates a test ruleset with a simple rule. */
273 ruleset_fd_tx =
274 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
275 ASSERT_LE(0, ruleset_fd_tx);
276 path_beneath_attr.parent_fd =
277 open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
278 ASSERT_LE(0, path_beneath_attr.parent_fd);
279 ASSERT_EQ(0,
280 landlock_add_rule(ruleset_fd_tx, LANDLOCK_RULE_PATH_BENEATH,
281 &path_beneath_attr, 0));
282 ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
283
284 /* Sends the ruleset FD over a socketpair and then close it. */
285 ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
286 socket_fds));
287 ASSERT_EQ(0, send_fd(socket_fds[0], ruleset_fd_tx));
288 ASSERT_EQ(0, close(socket_fds[0]));
289 ASSERT_EQ(0, close(ruleset_fd_tx));
290
291 child = fork();
292 ASSERT_LE(0, child);
293 if (child == 0) {
294 const int ruleset_fd_rx = recv_fd(socket_fds[1]);
295
296 ASSERT_LE(0, ruleset_fd_rx);
297 ASSERT_EQ(0, close(socket_fds[1]));
298
299 /* Enforces the received ruleset on the child. */
300 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
301 ASSERT_EQ(0, landlock_restrict_self(ruleset_fd_rx, 0));
302 ASSERT_EQ(0, close(ruleset_fd_rx));
303
304 /* Checks that the ruleset enforcement. */
305 ASSERT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
306 ASSERT_EQ(EACCES, errno);
307 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
308 ASSERT_LE(0, dir_fd);
309 ASSERT_EQ(0, close(dir_fd));
310 _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
311 return;
312 }
313
314 ASSERT_EQ(0, close(socket_fds[1]));
315
316 /* Checks that the parent is unrestricted. */
317 dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
318 ASSERT_LE(0, dir_fd);
319 ASSERT_EQ(0, close(dir_fd));
320 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
321 ASSERT_LE(0, dir_fd);
322 ASSERT_EQ(0, close(dir_fd));
323
324 ASSERT_EQ(child, waitpid(child, &status, 0));
325 ASSERT_EQ(1, WIFEXITED(status));
326 ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
327}
328
329TEST_HARNESS_MAIN