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 TEST(empty_path_beneath_attr) 125 { 126 const struct landlock_ruleset_attr ruleset_attr = { 127 .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE, 128 }; 129 const int ruleset_fd = 130 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); 131 132 ASSERT_LE(0, ruleset_fd); 133 134 /* Similar to struct landlock_path_beneath_attr.parent_fd = 0 */ 135 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, 136 NULL, 0)); 137 ASSERT_EQ(EFAULT, errno); 138 ASSERT_EQ(0, close(ruleset_fd)); 139 } 140 141 TEST(inval_fd_enforce) 142 { 143 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 144 145 ASSERT_EQ(-1, landlock_restrict_self(-1, 0)); 146 ASSERT_EQ(EBADF, errno); 147 } 148 149 TEST(unpriv_enforce_without_no_new_privs) 150 { 151 int err; 152 153 drop_caps(_metadata); 154 err = landlock_restrict_self(-1, 0); 155 ASSERT_EQ(EPERM, errno); 156 ASSERT_EQ(err, -1); 157 } 158 159 TEST(ruleset_fd_io) 160 { 161 struct landlock_ruleset_attr ruleset_attr = { 162 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, 163 }; 164 int ruleset_fd; 165 char buf; 166 167 drop_caps(_metadata); 168 ruleset_fd = 169 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); 170 ASSERT_LE(0, ruleset_fd); 171 172 ASSERT_EQ(-1, write(ruleset_fd, ".", 1)); 173 ASSERT_EQ(EINVAL, errno); 174 ASSERT_EQ(-1, read(ruleset_fd, &buf, 1)); 175 ASSERT_EQ(EINVAL, errno); 176 177 ASSERT_EQ(0, close(ruleset_fd)); 178 } 179 180 /* Tests enforcement of a ruleset FD transferred through a UNIX socket. */ 181 TEST(ruleset_fd_transfer) 182 { 183 struct landlock_ruleset_attr ruleset_attr = { 184 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR, 185 }; 186 struct landlock_path_beneath_attr path_beneath_attr = { 187 .allowed_access = LANDLOCK_ACCESS_FS_READ_DIR, 188 }; 189 int ruleset_fd_tx, dir_fd; 190 union { 191 /* Aligned ancillary data buffer. */ 192 char buf[CMSG_SPACE(sizeof(ruleset_fd_tx))]; 193 struct cmsghdr _align; 194 } cmsg_tx = {}; 195 char data_tx = '.'; 196 struct iovec io = { 197 .iov_base = &data_tx, 198 .iov_len = sizeof(data_tx), 199 }; 200 struct msghdr msg = { 201 .msg_iov = &io, 202 .msg_iovlen = 1, 203 .msg_control = &cmsg_tx.buf, 204 .msg_controllen = sizeof(cmsg_tx.buf), 205 }; 206 struct cmsghdr *cmsg; 207 int socket_fds[2]; 208 pid_t child; 209 int status; 210 211 drop_caps(_metadata); 212 213 /* Creates a test ruleset with a simple rule. */ 214 ruleset_fd_tx = 215 landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); 216 ASSERT_LE(0, ruleset_fd_tx); 217 path_beneath_attr.parent_fd = 218 open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC); 219 ASSERT_LE(0, path_beneath_attr.parent_fd); 220 ASSERT_EQ(0, 221 landlock_add_rule(ruleset_fd_tx, LANDLOCK_RULE_PATH_BENEATH, 222 &path_beneath_attr, 0)); 223 ASSERT_EQ(0, close(path_beneath_attr.parent_fd)); 224 225 cmsg = CMSG_FIRSTHDR(&msg); 226 ASSERT_NE(NULL, cmsg); 227 cmsg->cmsg_len = CMSG_LEN(sizeof(ruleset_fd_tx)); 228 cmsg->cmsg_level = SOL_SOCKET; 229 cmsg->cmsg_type = SCM_RIGHTS; 230 memcpy(CMSG_DATA(cmsg), &ruleset_fd_tx, sizeof(ruleset_fd_tx)); 231 232 /* Sends the ruleset FD over a socketpair and then close it. */ 233 ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, 234 socket_fds)); 235 ASSERT_EQ(sizeof(data_tx), sendmsg(socket_fds[0], &msg, 0)); 236 ASSERT_EQ(0, close(socket_fds[0])); 237 ASSERT_EQ(0, close(ruleset_fd_tx)); 238 239 child = fork(); 240 ASSERT_LE(0, child); 241 if (child == 0) { 242 int ruleset_fd_rx; 243 244 *(char *)msg.msg_iov->iov_base = '\0'; 245 ASSERT_EQ(sizeof(data_tx), 246 recvmsg(socket_fds[1], &msg, MSG_CMSG_CLOEXEC)); 247 ASSERT_EQ('.', *(char *)msg.msg_iov->iov_base); 248 ASSERT_EQ(0, close(socket_fds[1])); 249 cmsg = CMSG_FIRSTHDR(&msg); 250 ASSERT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(ruleset_fd_tx))); 251 memcpy(&ruleset_fd_rx, CMSG_DATA(cmsg), sizeof(ruleset_fd_tx)); 252 253 /* Enforces the received ruleset on the child. */ 254 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 255 ASSERT_EQ(0, landlock_restrict_self(ruleset_fd_rx, 0)); 256 ASSERT_EQ(0, close(ruleset_fd_rx)); 257 258 /* Checks that the ruleset enforcement. */ 259 ASSERT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); 260 ASSERT_EQ(EACCES, errno); 261 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 262 ASSERT_LE(0, dir_fd); 263 ASSERT_EQ(0, close(dir_fd)); 264 _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 265 return; 266 } 267 268 ASSERT_EQ(0, close(socket_fds[1])); 269 270 /* Checks that the parent is unrestricted. */ 271 dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 272 ASSERT_LE(0, dir_fd); 273 ASSERT_EQ(0, close(dir_fd)); 274 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 275 ASSERT_LE(0, dir_fd); 276 ASSERT_EQ(0, close(dir_fd)); 277 278 ASSERT_EQ(child, waitpid(child, &status, 0)); 279 ASSERT_EQ(1, WIFEXITED(status)); 280 ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status)); 281 } 282 283 TEST_HARNESS_MAIN 284