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 24 TEST(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 73 TEST(abi_version) 74 { 75 const struct landlock_ruleset_attr ruleset_attr = { 76 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, 77 }; 78 ASSERT_EQ(1, 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 TEST(inval_create_ruleset_flags) 101 { 102 const int last_flag = LANDLOCK_CREATE_RULESET_VERSION; 103 const int invalid_flag = last_flag << 1; 104 const struct landlock_ruleset_attr ruleset_attr = { 105 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, 106 }; 107 108 ASSERT_EQ(-1, landlock_create_ruleset(NULL, 0, invalid_flag)); 109 ASSERT_EQ(EINVAL, errno); 110 111 ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0, invalid_flag)); 112 ASSERT_EQ(EINVAL, errno); 113 114 ASSERT_EQ(-1, landlock_create_ruleset(NULL, sizeof(ruleset_attr), 115 invalid_flag)); 116 ASSERT_EQ(EINVAL, errno); 117 118 ASSERT_EQ(-1, 119 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 120 invalid_flag)); 121 ASSERT_EQ(EINVAL, errno); 122 } 123 124 /* Tests ordering of syscall argument checks. */ 125 TEST(add_rule_checks_ordering) 126 { 127 const struct landlock_ruleset_attr ruleset_attr = { 128 .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE, 129 }; 130 struct landlock_path_beneath_attr path_beneath_attr = { 131 .allowed_access = LANDLOCK_ACCESS_FS_EXECUTE, 132 .parent_fd = -1, 133 }; 134 const int ruleset_fd = 135 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); 136 137 ASSERT_LE(0, ruleset_fd); 138 139 /* Checks invalid flags. */ 140 ASSERT_EQ(-1, landlock_add_rule(-1, 0, NULL, 1)); 141 ASSERT_EQ(EINVAL, errno); 142 143 /* Checks invalid ruleset FD. */ 144 ASSERT_EQ(-1, landlock_add_rule(-1, 0, NULL, 0)); 145 ASSERT_EQ(EBADF, errno); 146 147 /* Checks invalid rule type. */ 148 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, 0, NULL, 0)); 149 ASSERT_EQ(EINVAL, errno); 150 151 /* Checks invalid rule attr. */ 152 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, 153 NULL, 0)); 154 ASSERT_EQ(EFAULT, errno); 155 156 /* Checks invalid path_beneath.parent_fd. */ 157 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, 158 &path_beneath_attr, 0)); 159 ASSERT_EQ(EBADF, errno); 160 161 /* Checks valid call. */ 162 path_beneath_attr.parent_fd = 163 open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC); 164 ASSERT_LE(0, path_beneath_attr.parent_fd); 165 ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, 166 &path_beneath_attr, 0)); 167 ASSERT_EQ(0, close(path_beneath_attr.parent_fd)); 168 ASSERT_EQ(0, close(ruleset_fd)); 169 } 170 171 TEST(inval_fd_enforce) 172 { 173 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 174 175 ASSERT_EQ(-1, landlock_restrict_self(-1, 0)); 176 ASSERT_EQ(EBADF, errno); 177 } 178 179 TEST(unpriv_enforce_without_no_new_privs) 180 { 181 int err; 182 183 drop_caps(_metadata); 184 err = landlock_restrict_self(-1, 0); 185 ASSERT_EQ(EPERM, errno); 186 ASSERT_EQ(err, -1); 187 } 188 189 TEST(ruleset_fd_io) 190 { 191 struct landlock_ruleset_attr ruleset_attr = { 192 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, 193 }; 194 int ruleset_fd; 195 char buf; 196 197 drop_caps(_metadata); 198 ruleset_fd = 199 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); 200 ASSERT_LE(0, ruleset_fd); 201 202 ASSERT_EQ(-1, write(ruleset_fd, ".", 1)); 203 ASSERT_EQ(EINVAL, errno); 204 ASSERT_EQ(-1, read(ruleset_fd, &buf, 1)); 205 ASSERT_EQ(EINVAL, errno); 206 207 ASSERT_EQ(0, close(ruleset_fd)); 208 } 209 210 /* Tests enforcement of a ruleset FD transferred through a UNIX socket. */ 211 TEST(ruleset_fd_transfer) 212 { 213 struct landlock_ruleset_attr ruleset_attr = { 214 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR, 215 }; 216 struct landlock_path_beneath_attr path_beneath_attr = { 217 .allowed_access = LANDLOCK_ACCESS_FS_READ_DIR, 218 }; 219 int ruleset_fd_tx, dir_fd; 220 union { 221 /* Aligned ancillary data buffer. */ 222 char buf[CMSG_SPACE(sizeof(ruleset_fd_tx))]; 223 struct cmsghdr _align; 224 } cmsg_tx = {}; 225 char data_tx = '.'; 226 struct iovec io = { 227 .iov_base = &data_tx, 228 .iov_len = sizeof(data_tx), 229 }; 230 struct msghdr msg = { 231 .msg_iov = &io, 232 .msg_iovlen = 1, 233 .msg_control = &cmsg_tx.buf, 234 .msg_controllen = sizeof(cmsg_tx.buf), 235 }; 236 struct cmsghdr *cmsg; 237 int socket_fds[2]; 238 pid_t child; 239 int status; 240 241 drop_caps(_metadata); 242 243 /* Creates a test ruleset with a simple rule. */ 244 ruleset_fd_tx = 245 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); 246 ASSERT_LE(0, ruleset_fd_tx); 247 path_beneath_attr.parent_fd = 248 open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC); 249 ASSERT_LE(0, path_beneath_attr.parent_fd); 250 ASSERT_EQ(0, 251 landlock_add_rule(ruleset_fd_tx, LANDLOCK_RULE_PATH_BENEATH, 252 &path_beneath_attr, 0)); 253 ASSERT_EQ(0, close(path_beneath_attr.parent_fd)); 254 255 cmsg = CMSG_FIRSTHDR(&msg); 256 ASSERT_NE(NULL, cmsg); 257 cmsg->cmsg_len = CMSG_LEN(sizeof(ruleset_fd_tx)); 258 cmsg->cmsg_level = SOL_SOCKET; 259 cmsg->cmsg_type = SCM_RIGHTS; 260 memcpy(CMSG_DATA(cmsg), &ruleset_fd_tx, sizeof(ruleset_fd_tx)); 261 262 /* Sends the ruleset FD over a socketpair and then close it. */ 263 ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, 264 socket_fds)); 265 ASSERT_EQ(sizeof(data_tx), sendmsg(socket_fds[0], &msg, 0)); 266 ASSERT_EQ(0, close(socket_fds[0])); 267 ASSERT_EQ(0, close(ruleset_fd_tx)); 268 269 child = fork(); 270 ASSERT_LE(0, child); 271 if (child == 0) { 272 int ruleset_fd_rx; 273 274 *(char *)msg.msg_iov->iov_base = '\0'; 275 ASSERT_EQ(sizeof(data_tx), 276 recvmsg(socket_fds[1], &msg, MSG_CMSG_CLOEXEC)); 277 ASSERT_EQ('.', *(char *)msg.msg_iov->iov_base); 278 ASSERT_EQ(0, close(socket_fds[1])); 279 cmsg = CMSG_FIRSTHDR(&msg); 280 ASSERT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(ruleset_fd_tx))); 281 memcpy(&ruleset_fd_rx, CMSG_DATA(cmsg), sizeof(ruleset_fd_tx)); 282 283 /* Enforces the received ruleset on the child. */ 284 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 285 ASSERT_EQ(0, landlock_restrict_self(ruleset_fd_rx, 0)); 286 ASSERT_EQ(0, close(ruleset_fd_rx)); 287 288 /* Checks that the ruleset enforcement. */ 289 ASSERT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); 290 ASSERT_EQ(EACCES, errno); 291 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 292 ASSERT_LE(0, dir_fd); 293 ASSERT_EQ(0, close(dir_fd)); 294 _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 295 return; 296 } 297 298 ASSERT_EQ(0, close(socket_fds[1])); 299 300 /* Checks that the parent is unrestricted. */ 301 dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 302 ASSERT_LE(0, dir_fd); 303 ASSERT_EQ(0, close(dir_fd)); 304 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 305 ASSERT_LE(0, dir_fd); 306 ASSERT_EQ(0, close(dir_fd)); 307 308 ASSERT_EQ(child, waitpid(child, &status, 0)); 309 ASSERT_EQ(1, WIFEXITED(status)); 310 ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status)); 311 } 312 313 TEST_HARNESS_MAIN 314