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// SPDX-License-Identifier: GPL-2.0
/*
* Landlock tests - Common user space base
*
* Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
* Copyright © 2019-2020 ANSSI
*/
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <linux/landlock.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include "common.h"
#ifndef O_PATH
#define O_PATH 010000000
#endif
TEST(inconsistent_attr) {
const long page_size = sysconf(_SC_PAGESIZE);
char *const buf = malloc(page_size + 1);
struct landlock_ruleset_attr *const ruleset_attr = (void *)buf;
ASSERT_NE(NULL, buf);
/* Checks copy_from_user(). */
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 0, 0));
/* The size if less than sizeof(struct landlock_attr_enforce). */
ASSERT_EQ(EINVAL, errno);
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 1, 0));
ASSERT_EQ(EINVAL, errno);
ASSERT_EQ(-1, landlock_create_ruleset(NULL, 1, 0));
/* The size if less than sizeof(struct landlock_attr_enforce). */
ASSERT_EQ(EFAULT, errno);
ASSERT_EQ(-1, landlock_create_ruleset(NULL,
sizeof(struct landlock_ruleset_attr), 0));
ASSERT_EQ(EFAULT, errno);
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0));
ASSERT_EQ(E2BIG, errno);
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr,
sizeof(struct landlock_ruleset_attr), 0));
ASSERT_EQ(ENOMSG, errno);
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0));
ASSERT_EQ(ENOMSG, errno);
/* Checks non-zero value. */
buf[page_size - 2] = '.';
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0));
ASSERT_EQ(E2BIG, errno);
ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0));
ASSERT_EQ(E2BIG, errno);
free(buf);
}
TEST(empty_path_beneath_attr) {
const struct landlock_ruleset_attr ruleset_attr = {
.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
};
const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
sizeof(ruleset_attr), 0);
ASSERT_LE(0, ruleset_fd);
/* Similar to struct landlock_path_beneath_attr.parent_fd = 0 */
ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
NULL, 0));
ASSERT_EQ(EFAULT, errno);
ASSERT_EQ(0, close(ruleset_fd));
}
TEST(inval_fd_enforce) {
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
ASSERT_EQ(-1, landlock_restrict_self(-1, 0));
ASSERT_EQ(EBADF, errno);
}
TEST(unpriv_enforce_without_no_new_privs) {
int err;
drop_caps(_metadata);
err = landlock_restrict_self(-1, 0);
ASSERT_EQ(EPERM, errno);
ASSERT_EQ(err, -1);
}
TEST(ruleset_fd_io)
{
struct landlock_ruleset_attr ruleset_attr = {
.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
};
int ruleset_fd;
char buf;
drop_caps(_metadata);
ruleset_fd = landlock_create_ruleset(&ruleset_attr,
sizeof(ruleset_attr), 0);
ASSERT_LE(0, ruleset_fd);
ASSERT_EQ(-1, write(ruleset_fd, ".", 1));
ASSERT_EQ(EINVAL, errno);
ASSERT_EQ(-1, read(ruleset_fd, &buf, 1));
ASSERT_EQ(EINVAL, errno);
ASSERT_EQ(0, close(ruleset_fd));
}
/* Tests enforcement of a ruleset FD transferred through a UNIX socket. */
TEST(ruleset_fd_transfer)
{
struct landlock_ruleset_attr ruleset_attr = {
.handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR,
};
struct landlock_path_beneath_attr path_beneath_attr = {
.allowed_access = LANDLOCK_ACCESS_FS_READ_DIR,
};
int ruleset_fd_tx, dir_fd;
union {
/* Aligned ancillary data buffer. */
char buf[CMSG_SPACE(sizeof(ruleset_fd_tx))];
struct cmsghdr _align;
} cmsg_tx = {};
char data_tx = '.';
struct iovec io = {
.iov_base = &data_tx,
.iov_len = sizeof(data_tx),
};
struct msghdr msg = {
.msg_iov = &io,
.msg_iovlen = 1,
.msg_control = &cmsg_tx.buf,
.msg_controllen = sizeof(cmsg_tx.buf),
};
struct cmsghdr *cmsg;
int socket_fds[2];
pid_t child;
int status;
drop_caps(_metadata);
/* Creates a test ruleset with a simple rule. */
ruleset_fd_tx = landlock_create_ruleset(&ruleset_attr,
sizeof(ruleset_attr), 0);
ASSERT_LE(0, ruleset_fd_tx);
path_beneath_attr.parent_fd = open("/tmp", O_PATH | O_NOFOLLOW |
O_DIRECTORY | O_CLOEXEC);
ASSERT_LE(0, path_beneath_attr.parent_fd);
ASSERT_EQ(0, landlock_add_rule(ruleset_fd_tx, LANDLOCK_RULE_PATH_BENEATH,
&path_beneath_attr, 0));
ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
cmsg = CMSG_FIRSTHDR(&msg);
ASSERT_NE(NULL, cmsg);
cmsg->cmsg_len = CMSG_LEN(sizeof(ruleset_fd_tx));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
memcpy(CMSG_DATA(cmsg), &ruleset_fd_tx, sizeof(ruleset_fd_tx));
/* Sends the ruleset FD over a socketpair and then close it. */
ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0, socket_fds));
ASSERT_EQ(sizeof(data_tx), sendmsg(socket_fds[0], &msg, 0));
ASSERT_EQ(0, close(socket_fds[0]));
ASSERT_EQ(0, close(ruleset_fd_tx));
child = fork();
ASSERT_LE(0, child);
if (child == 0) {
int ruleset_fd_rx;
*(char *)msg.msg_iov->iov_base = '\0';
ASSERT_EQ(sizeof(data_tx), recvmsg(socket_fds[1], &msg, MSG_CMSG_CLOEXEC));
ASSERT_EQ('.', *(char *)msg.msg_iov->iov_base);
ASSERT_EQ(0, close(socket_fds[1]));
cmsg = CMSG_FIRSTHDR(&msg);
ASSERT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(ruleset_fd_tx)));
memcpy(&ruleset_fd_rx, CMSG_DATA(cmsg), sizeof(ruleset_fd_tx));
/* Enforces the received ruleset on the child. */
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
ASSERT_EQ(0, landlock_restrict_self(ruleset_fd_rx, 0));
ASSERT_EQ(0, close(ruleset_fd_rx));
/* Checks that the ruleset enforcement. */
ASSERT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
ASSERT_EQ(EACCES, errno);
dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
ASSERT_LE(0, dir_fd);
ASSERT_EQ(0, close(dir_fd));
_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
return;
}
ASSERT_EQ(0, close(socket_fds[1]));
/* Checks that the parent is unrestricted. */
dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
ASSERT_LE(0, dir_fd);
ASSERT_EQ(0, close(dir_fd));
dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
ASSERT_LE(0, dir_fd);
ASSERT_EQ(0, close(dir_fd));
ASSERT_EQ(child, waitpid(child, &status, 0));
ASSERT_EQ(1, WIFEXITED(status));
ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
}
TEST_HARNESS_MAIN
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