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 const long page_size = sysconf(_SC_PAGESIZE); 26 char *const buf = malloc(page_size + 1); 27 struct landlock_ruleset_attr *const ruleset_attr = (void *)buf; 28 29 ASSERT_NE(NULL, buf); 30 31 /* Checks copy_from_user(). */ 32 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 0, 0)); 33 /* The size if less than sizeof(struct landlock_attr_enforce). */ 34 ASSERT_EQ(EINVAL, errno); 35 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 1, 0)); 36 ASSERT_EQ(EINVAL, errno); 37 38 ASSERT_EQ(-1, landlock_create_ruleset(NULL, 1, 0)); 39 /* The size if less than sizeof(struct landlock_attr_enforce). */ 40 ASSERT_EQ(EFAULT, errno); 41 42 ASSERT_EQ(-1, landlock_create_ruleset(NULL, 43 sizeof(struct landlock_ruleset_attr), 0)); 44 ASSERT_EQ(EFAULT, errno); 45 46 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0)); 47 ASSERT_EQ(E2BIG, errno); 48 49 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 50 sizeof(struct landlock_ruleset_attr), 0)); 51 ASSERT_EQ(ENOMSG, errno); 52 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0)); 53 ASSERT_EQ(ENOMSG, errno); 54 55 /* Checks non-zero value. */ 56 buf[page_size - 2] = '.'; 57 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0)); 58 ASSERT_EQ(E2BIG, errno); 59 60 ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0)); 61 ASSERT_EQ(E2BIG, errno); 62 63 free(buf); 64 } 65 66 TEST(empty_path_beneath_attr) { 67 const struct landlock_ruleset_attr ruleset_attr = { 68 .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE, 69 }; 70 const int ruleset_fd = landlock_create_ruleset(&ruleset_attr, 71 sizeof(ruleset_attr), 0); 72 73 ASSERT_LE(0, ruleset_fd); 74 75 /* Similar to struct landlock_path_beneath_attr.parent_fd = 0 */ 76 ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, 77 NULL, 0)); 78 ASSERT_EQ(EFAULT, errno); 79 ASSERT_EQ(0, close(ruleset_fd)); 80 } 81 82 TEST(inval_fd_enforce) { 83 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 84 85 ASSERT_EQ(-1, landlock_restrict_self(-1, 0)); 86 ASSERT_EQ(EBADF, errno); 87 } 88 89 TEST(unpriv_enforce_without_no_new_privs) { 90 int err; 91 92 drop_caps(_metadata); 93 err = landlock_restrict_self(-1, 0); 94 ASSERT_EQ(EPERM, errno); 95 ASSERT_EQ(err, -1); 96 } 97 98 TEST(ruleset_fd_io) 99 { 100 struct landlock_ruleset_attr ruleset_attr = { 101 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, 102 }; 103 int ruleset_fd; 104 char buf; 105 106 drop_caps(_metadata); 107 ruleset_fd = landlock_create_ruleset(&ruleset_attr, 108 sizeof(ruleset_attr), 0); 109 ASSERT_LE(0, ruleset_fd); 110 111 ASSERT_EQ(-1, write(ruleset_fd, ".", 1)); 112 ASSERT_EQ(EINVAL, errno); 113 ASSERT_EQ(-1, read(ruleset_fd, &buf, 1)); 114 ASSERT_EQ(EINVAL, errno); 115 116 ASSERT_EQ(0, close(ruleset_fd)); 117 } 118 119 /* Tests enforcement of a ruleset FD transferred through a UNIX socket. */ 120 TEST(ruleset_fd_transfer) 121 { 122 struct landlock_ruleset_attr ruleset_attr = { 123 .handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR, 124 }; 125 struct landlock_path_beneath_attr path_beneath_attr = { 126 .allowed_access = LANDLOCK_ACCESS_FS_READ_DIR, 127 }; 128 int ruleset_fd_tx, dir_fd; 129 union { 130 /* Aligned ancillary data buffer. */ 131 char buf[CMSG_SPACE(sizeof(ruleset_fd_tx))]; 132 struct cmsghdr _align; 133 } cmsg_tx = {}; 134 char data_tx = '.'; 135 struct iovec io = { 136 .iov_base = &data_tx, 137 .iov_len = sizeof(data_tx), 138 }; 139 struct msghdr msg = { 140 .msg_iov = &io, 141 .msg_iovlen = 1, 142 .msg_control = &cmsg_tx.buf, 143 .msg_controllen = sizeof(cmsg_tx.buf), 144 }; 145 struct cmsghdr *cmsg; 146 int socket_fds[2]; 147 pid_t child; 148 int status; 149 150 drop_caps(_metadata); 151 152 /* Creates a test ruleset with a simple rule. */ 153 ruleset_fd_tx = landlock_create_ruleset(&ruleset_attr, 154 sizeof(ruleset_attr), 0); 155 ASSERT_LE(0, ruleset_fd_tx); 156 path_beneath_attr.parent_fd = open("/tmp", O_PATH | O_NOFOLLOW | 157 O_DIRECTORY | O_CLOEXEC); 158 ASSERT_LE(0, path_beneath_attr.parent_fd); 159 ASSERT_EQ(0, landlock_add_rule(ruleset_fd_tx, LANDLOCK_RULE_PATH_BENEATH, 160 &path_beneath_attr, 0)); 161 ASSERT_EQ(0, close(path_beneath_attr.parent_fd)); 162 163 cmsg = CMSG_FIRSTHDR(&msg); 164 ASSERT_NE(NULL, cmsg); 165 cmsg->cmsg_len = CMSG_LEN(sizeof(ruleset_fd_tx)); 166 cmsg->cmsg_level = SOL_SOCKET; 167 cmsg->cmsg_type = SCM_RIGHTS; 168 memcpy(CMSG_DATA(cmsg), &ruleset_fd_tx, sizeof(ruleset_fd_tx)); 169 170 /* Sends the ruleset FD over a socketpair and then close it. */ 171 ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, socket_fds)); 172 ASSERT_EQ(sizeof(data_tx), sendmsg(socket_fds[0], &msg, 0)); 173 ASSERT_EQ(0, close(socket_fds[0])); 174 ASSERT_EQ(0, close(ruleset_fd_tx)); 175 176 child = fork(); 177 ASSERT_LE(0, child); 178 if (child == 0) { 179 int ruleset_fd_rx; 180 181 *(char *)msg.msg_iov->iov_base = '\0'; 182 ASSERT_EQ(sizeof(data_tx), recvmsg(socket_fds[1], &msg, MSG_CMSG_CLOEXEC)); 183 ASSERT_EQ('.', *(char *)msg.msg_iov->iov_base); 184 ASSERT_EQ(0, close(socket_fds[1])); 185 cmsg = CMSG_FIRSTHDR(&msg); 186 ASSERT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(ruleset_fd_tx))); 187 memcpy(&ruleset_fd_rx, CMSG_DATA(cmsg), sizeof(ruleset_fd_tx)); 188 189 /* Enforces the received ruleset on the child. */ 190 ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); 191 ASSERT_EQ(0, landlock_restrict_self(ruleset_fd_rx, 0)); 192 ASSERT_EQ(0, close(ruleset_fd_rx)); 193 194 /* Checks that the ruleset enforcement. */ 195 ASSERT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); 196 ASSERT_EQ(EACCES, errno); 197 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 198 ASSERT_LE(0, dir_fd); 199 ASSERT_EQ(0, close(dir_fd)); 200 _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); 201 return; 202 } 203 204 ASSERT_EQ(0, close(socket_fds[1])); 205 206 /* Checks that the parent is unrestricted. */ 207 dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 208 ASSERT_LE(0, dir_fd); 209 ASSERT_EQ(0, close(dir_fd)); 210 dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC); 211 ASSERT_LE(0, dir_fd); 212 ASSERT_EQ(0, close(dir_fd)); 213 214 ASSERT_EQ(child, waitpid(child, &status, 0)); 215 ASSERT_EQ(1, WIFEXITED(status)); 216 ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status)); 217 } 218 219 TEST_HARNESS_MAIN 220