From: Mickaël Salaün <m...@linux.microsoft.com>
Test all Landlock system calls, ptrace hooks semantic and filesystem
access-control.
Test coverage for security/landlock/ is 95.2% of lines. The code not
covered only deals with internal kernel errors (e.g. memory allocation)
and race conditions.
Cc: James Morris <jmor...@namei.org>
Cc: Jann Horn <ja...@google.com>
Cc: Kees Cook <keesc...@chromium.org>
Cc: Serge E. Hallyn <se...@hallyn.com>
Cc: Shuah Khan <sh...@kernel.org>
Signed-off-by: Mickaël Salaün <m...@linux.microsoft.com>
Reviewed-by: Vincent Dagonneau <vincent.dagonn...@ssi.gouv.fr>
---
Changes since v21:
* Remove layout1.chroot test and update layout1.unhandled_access to not
rely on LANDLOCK_ACCESS_FS_CHROOT.
* Clean up comments.
Changes since v20:
* Update with new syscalls and type names.
* Use the full syscall interfaces: explicitely set the "flags" field to
zero.
* Update the empty_path_beneath_attr test to check for EFAULT.
* Update and merge tests for the simplified copy_min_struct_from_user().
* Clean up makefile.
* Rename some types and variables in a more consistent way.
Changes since v19:
* Update with the new Landlock syscalls.
* Fix device creation.
* Check the new landlock_attr_features members: last_rule_type and
last_target_type .
* Constify variables.
Changes since v18:
* Replace ruleset_rw.inval with layout1.inval to avoid inexistent test
layout.
* Use the new FIXTURE_VARIANT for ptrace_test: makes the tests more
readable and usable.
* Add ARRAY_SIZE() macro to please checkpatch.
Changes since v17:
* Add new test for mknod with a zero mode.
* Use memset(3) to initialize attr_features in base_test.
Changes since v16:
* Add new unpriv_enforce_without_no_new_privs test: check that ruleset
enforcing is forbiden without no_new_privs and CAP_SYS_ADMIN.
* Drop capabilities when useful.
* Check the new size_attr_features field from struct
landlock_attr_features.
* Update the empty_or_same_ruleset test to check complementary empty
ruleset.
* Update base_test according to the new attribute structures and fix the
inconsistent_attr test accordingly.
* Switch syscall attribute pointer and size arguments.
* Rename test files with a "_test" suffix.
Changes since v14:
* Add new tests:
- superset: check new layer bitmask.
- max_layers: check maximum number of layers.
- release_inodes: check that umount work well.
- empty_or_same_ruleset.
- inconsistent_attr: checks copy_to_user limits.
- in ruleset_rw.inval to check ruleset FD.
- proc_unlinked_file: check file access through /proc/self/fd .
- file_access_rights: check that a file can only get consistent access
rights.
- unpriv: check that NO_NEW_PRIVS or CAP_SYS_ADMIN is required.
- check pipe access through /proc/self/fd .
- check move_mount(2).
- check ruleset file descriptor properties.
- proc_nsfs: extend to check that internal filesystems (e.g. nsfs) are
allowed.
* Double-check read and write effective actions.
* Fix potential desynchronization between the kernel sources and
installed headers by overriding the build step in the Makefile. This
also enable to build with Clang.
* Add two files in the test directories (for link test and rename test).
* Remove test for ruleset's show_fdinfo().
* Replace EBADR with EBADFD.
* Update tests accordingly to the changes of rename and link rights.
* Fix (now) illegal access rights tied to files.
* Update rename and link tests.
* Remove superfluous '\n' in TH_LOG() calls.
* Make assert calls consistent and readable.
* Fix the execute test.
* Make tests future-proof.
* Cosmetic fixes.
Changes since v14:
* Add new tests:
- Compatibility: empty_attr_{ruleset,path_beneath,enforce} to check
minimal attr size.
- Access types: link_to, rename_from, rename_to, rmdir, unlink,
make_char, make_block, make_reg, make_sock, make_fifo, make_sym,
make_dir, chroot, execute.
- Test privilege escalation prevention by enforcing a nested rule, on
a parent directory, with less restrictions than one on a child
directory.
- Test for empty and more than 32-bits allowed_access
* Merge the two test mount hierarchies.
* Complete relative path tests by combining chdir and chroot.
* Adjust tests:
- Remove the layout1/extend_ruleset_with_denied_path test.
- Extend layout1/whitelist test with checks on file.
- Add and use create_dir_and_file().
* Only use read/write checks but not stat(2) for tests.
* Rename test.h to common.h and improve it.
* Rename path name to make them more consistent, easy to understand and
make them in a common directory.
* Make create_ruleset() more generic.
* Constify variables.
* Re-add static global variables.
* Remove useless openat(2).
* Fix and complete kernel config.
* Set umask and clean up file modes.
* Clean up open flags.
* Improve Makefile.
* Fix spelling.
* Improve comments and error messages.
Changes since v13:
* Add back the filesystem tests (from v10) and extend them.
* Add tests for the new syscall.
Previous changes:
https://lore.kernel.org/lkml/20191104172146.30797-7-...@digikod.net/
---
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/landlock/.gitignore | 2 +
tools/testing/selftests/landlock/Makefile | 24 +
tools/testing/selftests/landlock/base_test.c | 117 ++
tools/testing/selftests/landlock/common.h | 113 ++
tools/testing/selftests/landlock/config | 5 +
tools/testing/selftests/landlock/fs_test.c | 1675 +++++++++++++++++
.../testing/selftests/landlock/ptrace_test.c | 307 +++
tools/testing/selftests/landlock/true.c | 5 +
9 files changed, 2249 insertions(+)
create mode 100644 tools/testing/selftests/landlock/.gitignore
create mode 100644 tools/testing/selftests/landlock/Makefile
create mode 100644 tools/testing/selftests/landlock/base_test.c
create mode 100644 tools/testing/selftests/landlock/common.h
create mode 100644 tools/testing/selftests/landlock/config
create mode 100644 tools/testing/selftests/landlock/fs_test.c
create mode 100644 tools/testing/selftests/landlock/ptrace_test.c
create mode 100644 tools/testing/selftests/landlock/true.c
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index d9c283503159..f40a34430652 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -26,6 +26,7 @@ TARGETS += ir
TARGETS += kcmp
TARGETS += kexec
TARGETS += kvm
+TARGETS += landlock
TARGETS += lib
TARGETS += livepatch
TARGETS += lkdtm
diff --git a/tools/testing/selftests/landlock/.gitignore
b/tools/testing/selftests/landlock/.gitignore
new file mode 100644
index 000000000000..470203a7cd73
--- /dev/null
+++ b/tools/testing/selftests/landlock/.gitignore
@@ -0,0 +1,2 @@
+/*_test
+/true
diff --git a/tools/testing/selftests/landlock/Makefile
b/tools/testing/selftests/landlock/Makefile
new file mode 100644
index 000000000000..a99596ca9882
--- /dev/null
+++ b/tools/testing/selftests/landlock/Makefile
@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CFLAGS += -Wall -O2
+
+src_test := $(wildcard *_test.c)
+
+TEST_GEN_PROGS := $(src_test:.c=)
+
+TEST_GEN_PROGS_EXTENDED := true
+
+KSFT_KHDR_INSTALL := 1
+OVERRIDE_TARGETS := 1
+include ../lib.mk
+
+khdr_dir = $(top_srcdir)/usr/include
+
+$(khdr_dir)/linux/landlock.h: khdr
+ @:
+
+$(OUTPUT)/true: true.c
+ $(LINK.c) $< $(LDLIBS) -o $@ -static
+
+$(OUTPUT)/%_test: %_test.c $(khdr_dir)/linux/landlock.h ../kselftest_harness.h
common.h
+ $(LINK.c) $< $(LDLIBS) -o $@ -lcap -I$(khdr_dir)
diff --git a/tools/testing/selftests/landlock/base_test.c
b/tools/testing/selftests/landlock/base_test.c
new file mode 100644
index 000000000000..cb35eb91516b
--- /dev/null
+++ b/tools/testing/selftests/landlock/base_test.c
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Landlock tests - Common user space base
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <m...@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 "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_enforce_ruleset_current(-1, 0));
+ ASSERT_EQ(EBADF, errno);
+}
+
+TEST(unpriv_enforce_without_no_new_privs) {
+ int err;
+
+ disable_caps(_metadata);
+ err = landlock_enforce_ruleset_current(-1, 0);
+ ASSERT_EQ(errno, EPERM);
+ ASSERT_EQ(err, -1);
+}
+
+TEST(ruleset_fd)
+{
+ struct landlock_ruleset_attr ruleset_attr = {
+ .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
+ };
+ int ruleset_fd;
+ char buf;
+
+ disable_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));
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/landlock/common.h
b/tools/testing/selftests/landlock/common.h
new file mode 100644
index 000000000000..ab86f3f23ff4
--- /dev/null
+++ b/tools/testing/selftests/landlock/common.h
@@ -0,0 +1,113 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Landlock test helpers
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <m...@digikod.net>
+ * Copyright © 2019-2020 ANSSI
+ */
+
+#include <errno.h>
+#include <linux/landlock.h>
+#include <sys/capability.h>
+#include <sys/syscall.h>
+
+#include "../kselftest_harness.h"
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+#ifndef landlock_create_ruleset
+static inline int landlock_create_ruleset(
+ const struct landlock_ruleset_attr *const attr,
+ const size_t size, const __u32 flags)
+{
+ errno = 0;
+ return syscall(__NR_landlock_create_ruleset, attr, size, flags);
+}
+#endif
+
+#ifndef landlock_add_rule
+static inline int landlock_add_rule(const int ruleset_fd,
+ const enum landlock_rule_type rule_type,
+ const void *const rule_attr, const __u32 flags)
+{
+ errno = 0;
+ return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type,
+ rule_attr, flags);
+}
+#endif
+
+#ifndef landlock_enforce_ruleset_current
+static inline int landlock_enforce_ruleset_current(const int ruleset_fd,
+ const __u32 flags)
+{
+ errno = 0;
+ return syscall(__NR_landlock_enforce_ruleset_current, ruleset_fd,
+ flags);
+}
+#endif
+
+static void disable_caps(struct __test_metadata *const _metadata)
+{
+ cap_t cap_p;
+ /* Only these two capabilities are useful for the tests. */
+ const cap_value_t caps[] = {
+ CAP_MKNOD,
+ CAP_SYS_ADMIN,
+ CAP_SYS_CHROOT,
+ };
+
+ cap_p = cap_get_proc();
+ ASSERT_NE(NULL, cap_p) {
+ TH_LOG("Failed to cap_get_proc: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_clear(cap_p)) {
+ TH_LOG("Failed to cap_clear: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_set_flag(cap_p, CAP_PERMITTED, ARRAY_SIZE(caps),
+ caps, CAP_SET)) {
+ TH_LOG("Failed to cap_set_flag: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_set_proc(cap_p)) {
+ TH_LOG("Failed to cap_set_proc: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_free(cap_p)) {
+ TH_LOG("Failed to cap_free: %s", strerror(errno));
+ }
+}
+
+static void effective_cap(struct __test_metadata *const _metadata,
+ const cap_value_t caps, const cap_flag_value_t value)
+{
+ cap_t cap_p;
+
+ cap_p = cap_get_proc();
+ ASSERT_NE(NULL, cap_p) {
+ TH_LOG("Failed to cap_get_proc: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_set_flag(cap_p, CAP_EFFECTIVE, 1, &caps, value)) {
+ TH_LOG("Failed to cap_set_flag: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_set_proc(cap_p)) {
+ TH_LOG("Failed to cap_set_proc: %s", strerror(errno));
+ }
+ ASSERT_NE(-1, cap_free(cap_p)) {
+ TH_LOG("Failed to cap_free: %s", strerror(errno));
+ }
+}
+
+/* We cannot put such helpers in a library because of kselftest_harness.h . */
+__attribute__((__unused__))
+static void set_cap(struct __test_metadata *const _metadata,
+ const cap_value_t caps)
+{
+ effective_cap(_metadata, caps, CAP_SET);
+}
+
+__attribute__((__unused__))
+static void clear_cap(struct __test_metadata *const _metadata,
+ const cap_value_t caps)
+{
+ effective_cap(_metadata, caps, CAP_CLEAR);
+}
diff --git a/tools/testing/selftests/landlock/config
b/tools/testing/selftests/landlock/config
new file mode 100644
index 000000000000..042298105821
--- /dev/null
+++ b/tools/testing/selftests/landlock/config
@@ -0,0 +1,5 @@
+CONFIG_SECURITY_LANDLOCK=y
+CONFIG_SECURITY_PATH=y
+CONFIG_SECURITY=y
+CONFIG_SHMEM=y
+CONFIG_TMPFS=y
diff --git a/tools/testing/selftests/landlock/fs_test.c
b/tools/testing/selftests/landlock/fs_test.c
new file mode 100644
index 000000000000..48ec65ec05a6
--- /dev/null
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -0,0 +1,1675 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Landlock tests - Filesystem
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <m...@digikod.net>
+ * Copyright © 2020 ANSSI
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <linux/landlock.h>
+#include <sched.h>
+#include <string.h>
+#include <sys/capability.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/sendfile.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <unistd.h>
+
+#include "common.h"
+
+#define TMP_DIR "tmp/"
+#define FILE_1 "file1"
+#define FILE_2 "file2"
+#define BINARY_PATH "./true"
+
+/* Paths (sibling number and depth) */
+static const char dir_s1d1[] = TMP_DIR "s1d1";
+static const char file1_s1d1[] = TMP_DIR "s1d1/" FILE_1;
+static const char file2_s1d1[] = TMP_DIR "s1d1/" FILE_2;
+static const char dir_s1d2[] = TMP_DIR "s1d1/s1d2";
+static const char file1_s1d2[] = TMP_DIR "s1d1/s1d2/" FILE_1;
+static const char file2_s1d2[] = TMP_DIR "s1d1/s1d2/" FILE_2;
+static const char dir_s1d3[] = TMP_DIR "s1d1/s1d2/s1d3";
+static const char file1_s1d3[] = TMP_DIR "s1d1/s1d2/s1d3/" FILE_1;
+static const char file2_s1d3[] = TMP_DIR "s1d1/s1d2/s1d3/" FILE_2;
+
+static const char dir_s2d1[] = TMP_DIR "s2d1";
+static const char file1_s2d1[] = TMP_DIR "s2d1/" FILE_1;
+static const char dir_s2d2[] = TMP_DIR "s2d1/s2d2";
+static const char file1_s2d2[] = TMP_DIR "s2d1/s2d2/" FILE_1;
+static const char dir_s2d3[] = TMP_DIR "s2d1/s2d2/s2d3";
+static const char file1_s2d3[] = TMP_DIR "s2d1/s2d2/s2d3/" FILE_1;
+static const char file2_s2d3[] = TMP_DIR "s2d1/s2d2/s2d3/" FILE_2;
+
+static const char dir_s3d1[] = TMP_DIR "s3d1";
+/* dir_s3d2 is a mount point. */
+static const char dir_s3d2[] = TMP_DIR "s3d1/s3d2";
+static const char dir_s3d3[] = TMP_DIR "s3d1/s3d2/s3d3";
+
+static void create_dir_and_file(struct __test_metadata *const _metadata,
+ const char *const dir_path)
+{
+ int file_fd;
+ char *const file1_path = alloca(strlen(dir_path) + sizeof(FILE_1) + 2);
+ char *const file2_path = alloca(strlen(dir_path) + sizeof(FILE_2) + 2);
+
+ strcpy(file1_path, dir_path);
+ strcat(file1_path, "/");
+ strcat(file1_path, FILE_1);
+
+ strcpy(file2_path, dir_path);
+ strcat(file2_path, "/");
+ strcat(file2_path, FILE_2);
+
+ ASSERT_EQ(0, mkdir(dir_path, 0700)) {
+ TH_LOG("Failed to create directory \"%s\": %s", dir_path,
+ strerror(errno));
+ }
+ file_fd = open(file1_path, O_CREAT | O_EXCL | O_WRONLY | O_CLOEXEC,
+ 0700);
+ ASSERT_LE(0, file_fd);
+ ASSERT_EQ(0, close(file_fd));
+
+ file_fd = open(file2_path, O_CREAT | O_EXCL | O_WRONLY | O_CLOEXEC,
+ 0700);
+ ASSERT_LE(0, file_fd);
+ ASSERT_EQ(0, close(file_fd));
+}
+
+static void delete_dir_and_file(const char *const dir_path)
+{
+ char *const file1_path = alloca(strlen(dir_path) +
+ sizeof(FILE_1) + 2);
+ char *const file2_path = alloca(strlen(dir_path) +
+ sizeof(FILE_2) + 2);
+
+ strcpy(file1_path, dir_path);
+ strcat(file1_path, "/");
+ strcat(file1_path, FILE_1);
+
+ strcpy(file2_path, dir_path);
+ strcat(file2_path, "/");
+ strcat(file2_path, FILE_2);
+
+ unlink(file1_path);
+ unlink(file2_path);
+ /* file1_path may be a directory, cf. layout1/make_directory. */
+ rmdir(file1_path);
+ rmdir(dir_path);
+}
+
+static void cleanup_layout1(struct __test_metadata *const _metadata)
+{
+ delete_dir_and_file(dir_s1d3);
+ delete_dir_and_file(dir_s1d2);
+ delete_dir_and_file(dir_s1d1);
+
+ delete_dir_and_file(dir_s2d3);
+ delete_dir_and_file(dir_s2d2);
+ delete_dir_and_file(dir_s2d1);
+
+ delete_dir_and_file(dir_s3d3);
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ umount(dir_s3d2);
+ clear_cap(_metadata, CAP_SYS_ADMIN);
+ delete_dir_and_file(dir_s3d2);
+ delete_dir_and_file(dir_s3d1);
+
+ delete_dir_and_file(TMP_DIR);
+}
+
+FIXTURE(layout1) {
+};
+
+FIXTURE_SETUP(layout1)
+{
+ disable_caps(_metadata);
+ cleanup_layout1(_metadata);
+
+ /* Do not pollute the rest of the system. */
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ ASSERT_EQ(0, unshare(CLONE_NEWNS));
+ clear_cap(_metadata, CAP_SYS_ADMIN);
+ umask(0077);
+ create_dir_and_file(_metadata, TMP_DIR);
+
+ create_dir_and_file(_metadata, dir_s1d1);
+ create_dir_and_file(_metadata, dir_s1d2);
+ create_dir_and_file(_metadata, dir_s1d3);
+
+ create_dir_and_file(_metadata, dir_s2d1);
+ create_dir_and_file(_metadata, dir_s2d2);
+ create_dir_and_file(_metadata, dir_s2d3);
+
+ create_dir_and_file(_metadata, dir_s3d1);
+ create_dir_and_file(_metadata, dir_s3d2);
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ ASSERT_EQ(0, mount("tmp", dir_s3d2, "tmpfs", 0, "size=4m,mode=700"));
+ clear_cap(_metadata, CAP_SYS_ADMIN);
+ create_dir_and_file(_metadata, dir_s3d3);
+}
+
+FIXTURE_TEARDOWN(layout1)
+{
+ /*
+ * cleanup_layout1() would be denied here, use TEST(cleanup) instead.
+ */
+}
+
+static void test_path_rel(struct __test_metadata *const _metadata,
+ const int dirfd, const char *const path, const int ret)
+{
+ int fd;
+
+ /* Works with file and directories. */
+ fd = openat(dirfd, path, O_RDONLY | O_CLOEXEC);
+ if (ret) {
+ ASSERT_EQ(-1, fd) {
+ TH_LOG("Successfully opened \"%s\": %s", path,
+ strerror(errno));
+ }
+ ASSERT_EQ(EACCES, errno) {
+ TH_LOG("Wrong error code to open \"%s\": %s", path,
+ strerror(errno));
+ }
+ } else {
+ ASSERT_LE(0, fd) {
+ TH_LOG("Failed to open \"%s\": %s", path,
+ strerror(errno));
+ }
+ EXPECT_EQ(0, close(fd));
+ }
+}
+
+static void test_path(struct __test_metadata *const _metadata,
+ const char *const path, const int ret)
+{
+ return test_path_rel(_metadata, AT_FDCWD, path, ret);
+}
+
+TEST_F(layout1, no_restriction)
+{
+ test_path(_metadata, dir_s1d1, 0);
+ test_path(_metadata, file1_s1d1, 0);
+ test_path(_metadata, file2_s1d1, 0);
+ test_path(_metadata, dir_s1d2, 0);
+ test_path(_metadata, file1_s1d2, 0);
+ test_path(_metadata, file2_s1d2, 0);
+ test_path(_metadata, dir_s1d3, 0);
+ test_path(_metadata, file1_s1d3, 0);
+
+ test_path(_metadata, dir_s2d1, 0);
+ test_path(_metadata, file1_s2d1, 0);
+ test_path(_metadata, dir_s2d2, 0);
+ test_path(_metadata, file1_s2d2, 0);
+ test_path(_metadata, dir_s2d3, 0);
+ test_path(_metadata, file1_s2d3, 0);
+
+ test_path(_metadata, dir_s3d1, 0);
+ test_path(_metadata, dir_s3d2, 0);
+ test_path(_metadata, dir_s3d3, 0);
+}
+
+TEST_F(layout1, inval)
+{
+ struct landlock_path_beneath_attr path_beneath = {
+ .allowed_access = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE,
+ .parent_fd = -1,
+ };
+ struct landlock_ruleset_attr ruleset_attr = {
+ .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE,
+ };
+ int ruleset_fd;
+
+ path_beneath.parent_fd = open(dir_s1d2, O_PATH | O_DIRECTORY |
+ O_CLOEXEC);
+ ASSERT_LE(0, path_beneath.parent_fd);
+
+ ruleset_fd = open(dir_s1d1, O_PATH | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, ruleset_fd);
+ ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ /* Returns EBADF because ruleset_fd contains O_PATH. */
+ ASSERT_EQ(EBADF, errno);
+ ASSERT_EQ(0, close(ruleset_fd));
+
+ ruleset_fd = open(dir_s1d1, O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, ruleset_fd);
+ ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ /* Returns EBADFD because ruleset_fd is not a valid ruleset. */
+ ASSERT_EQ(EBADFD, errno);
+ ASSERT_EQ(0, close(ruleset_fd));
+
+ /* Gets a real ruleset. */
+ ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+ ASSERT_LE(0, ruleset_fd);
+ ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+
+ /* Tests without O_PATH. */
+ path_beneath.parent_fd = open(dir_s1d2, O_DIRECTORY |
+ O_CLOEXEC);
+ ASSERT_LE(0, path_beneath.parent_fd);
+ ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ ASSERT_EQ(EBADFD, errno);
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+
+ /* Checks unhandled allowed_access. */
+ path_beneath.parent_fd = open(dir_s1d2, O_PATH | O_DIRECTORY |
+ O_CLOEXEC);
+ ASSERT_LE(0, path_beneath.parent_fd);
+
+ /* Test with legitimate values. */
+ path_beneath.allowed_access |= LANDLOCK_ACCESS_FS_EXECUTE;
+ ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ ASSERT_EQ(EINVAL, errno);
+ path_beneath.allowed_access &= ~LANDLOCK_ACCESS_FS_EXECUTE;
+
+ /* Test with unknown (64-bits) value. */
+ path_beneath.allowed_access |= (1ULL << 60);
+ ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ ASSERT_EQ(EINVAL, errno);
+ path_beneath.allowed_access &= ~(1ULL << 60);
+
+ /* Test with no access. */
+ path_beneath.allowed_access = 0;
+ ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ path_beneath.allowed_access &= ~(1ULL << 60);
+
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+
+ /* Enforces the ruleset. */
+ ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+ ASSERT_EQ(0, landlock_enforce_ruleset_current(ruleset_fd, 0));
+
+ ASSERT_EQ(0, close(ruleset_fd));
+}
+
+#define ACCESS_FILE ( \
+ LANDLOCK_ACCESS_FS_EXECUTE | \
+ LANDLOCK_ACCESS_FS_WRITE_FILE | \
+ LANDLOCK_ACCESS_FS_READ_FILE)
+
+#define ACCESS_LAST LANDLOCK_ACCESS_FS_MAKE_SYM
+
+#define ACCESS_ALL ( \
+ ACCESS_FILE | \
+ LANDLOCK_ACCESS_FS_READ_DIR | \
+ LANDLOCK_ACCESS_FS_REMOVE_DIR | \
+ LANDLOCK_ACCESS_FS_REMOVE_FILE | \
+ LANDLOCK_ACCESS_FS_MAKE_CHAR | \
+ LANDLOCK_ACCESS_FS_MAKE_DIR | \
+ LANDLOCK_ACCESS_FS_MAKE_REG | \
+ LANDLOCK_ACCESS_FS_MAKE_SOCK | \
+ LANDLOCK_ACCESS_FS_MAKE_FIFO | \
+ LANDLOCK_ACCESS_FS_MAKE_BLOCK | \
+ ACCESS_LAST)
+
+TEST_F(layout1, file_access_rights)
+{
+ __u64 access;
+ int err;
+ struct landlock_path_beneath_attr path_beneath = {};
+ struct landlock_ruleset_attr ruleset_attr = {
+ .handled_access_fs = ACCESS_ALL,
+ };
+ const int ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ /* Tests access rights for files. */
+ path_beneath.parent_fd = open(file1_s1d2, O_PATH | O_CLOEXEC);
+ ASSERT_LE(0, path_beneath.parent_fd);
+ for (access = 1; access <= ACCESS_LAST; access <<= 1) {
+ path_beneath.allowed_access = access;
+ err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0);
+ if ((access | ACCESS_FILE) == ACCESS_FILE) {
+ ASSERT_EQ(0, err);
+ } else {
+ ASSERT_EQ(-1, err);
+ ASSERT_EQ(EINVAL, errno);
+ }
+ }
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+}
+
+static void add_path_beneath(struct __test_metadata *const _metadata,
+ const int ruleset_fd, const __u64 allowed_access,
+ const char *const path)
+{
+ struct landlock_path_beneath_attr path_beneath = {
+ .allowed_access = allowed_access,
+ };
+
+ path_beneath.parent_fd = open(path, O_PATH | O_CLOEXEC);
+ ASSERT_LE(0, path_beneath.parent_fd) {
+ TH_LOG("Failed to open directory \"%s\": %s", path,
+ strerror(errno));
+ }
+ ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0)) {
+ TH_LOG("Failed to update the ruleset with \"%s\": %s", path,
+ strerror(errno));
+ }
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+}
+
+struct rule {
+ const char *path;
+ __u64 access;
+};
+
+#define ACCESS_RO ( \
+ LANDLOCK_ACCESS_FS_READ_FILE | \
+ LANDLOCK_ACCESS_FS_READ_DIR)
+
+#define ACCESS_RW ( \
+ ACCESS_RO | \
+ LANDLOCK_ACCESS_FS_WRITE_FILE)
+
+static int create_ruleset(struct __test_metadata *const _metadata,
+ const __u64 handled_access_fs, const struct rule rules[])
+{
+ int ruleset_fd, i;
+ struct landlock_ruleset_attr ruleset_attr = {
+ .handled_access_fs = handled_access_fs,
+ };
+
+ ASSERT_NE(NULL, rules) {
+ TH_LOG("No rule list");
+ }
+ ASSERT_NE(NULL, rules[0].path) {
+ TH_LOG("Empty rule list");
+ }
+
+ ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+ ASSERT_LE(0, ruleset_fd) {
+ TH_LOG("Failed to create a ruleset: %s", strerror(errno));
+ }
+
+ for (i = 0; rules[i].path; i++) {
+ add_path_beneath(_metadata, ruleset_fd, rules[i].access,
+ rules[i].path);
+ }
+ return ruleset_fd;
+}
+
+static void enforce_ruleset(struct __test_metadata *const _metadata,
+ const int ruleset_fd)
+{
+ ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+ ASSERT_EQ(0, landlock_enforce_ruleset_current(ruleset_fd, 0)) {
+ TH_LOG("Failed to enforce ruleset: %s", strerror(errno));
+ }
+}
+
+TEST_F(layout1, proc_nsfs)
+{
+ const struct rule rules[] = {
+ {
+ .path = "/dev/null",
+ .access = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE,
+ },
+ {}
+ };
+ struct landlock_path_beneath_attr path_beneath;
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access |
+ LANDLOCK_ACCESS_FS_READ_DIR, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ test_path(_metadata, "/proc/self/ns/mnt", 0);
+
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ test_path(_metadata, "/", -1);
+ test_path(_metadata, "/dev", -1);
+ test_path(_metadata, "/dev/null", 0);
+ test_path(_metadata, "/dev/full", -1);
+
+ test_path(_metadata, "/proc", -1);
+ test_path(_metadata, "/proc/self", -1);
+ test_path(_metadata, "/proc/self/ns", -1);
+ /*
+ * Because nsfs is an internal filesystem, /proc/self/ns/mnt is a
+ * disconnected path. Such path cannot be identified and must then be
+ * allowed.
+ */
+ test_path(_metadata, "/proc/self/ns/mnt", 0);
+
+ /*
+ * Checks that it is not possible to add nsfs-like filesystem
+ * references to a ruleset.
+ */
+ path_beneath.allowed_access = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE,
+ path_beneath.parent_fd = open("/proc/self/ns/mnt", O_PATH | O_CLOEXEC);
+ ASSERT_LE(0, path_beneath.parent_fd);
+ ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath, 0));
+ ASSERT_EQ(EBADFD, errno);
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+}
+
+static void drop_privileges(struct __test_metadata *const _metadata)
+{
+ cap_t caps;
+ const cap_value_t cap_val = CAP_SYS_ADMIN;
+
+ caps = cap_get_proc();
+ ASSERT_NE(NULL, caps);
+ ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_val,
+ CAP_CLEAR));
+ ASSERT_EQ(0, cap_set_proc(caps));
+ ASSERT_EQ(0, cap_free(caps));
+}
+
+TEST_F(layout1, unpriv) {
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ int ruleset_fd;
+
+ drop_privileges(_metadata);
+ ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules);
+ ASSERT_LE(0, ruleset_fd);
+ ASSERT_EQ(-1, landlock_enforce_ruleset_current(ruleset_fd, 0));
+ ASSERT_EQ(EPERM, errno);
+
+ /* enforce_ruleset() calls prctl(no_new_privs). */
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(layout1, whitelist)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = ACCESS_RO,
+ },
+ {
+ .path = file1_s2d2,
+ .access = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+ char buf;
+ int reg_fd;
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /* Tests on a directory. */
+ test_path(_metadata, "/", -1);
+ test_path(_metadata, dir_s1d1, -1);
+ test_path(_metadata, file1_s1d1, -1);
+ test_path(_metadata, dir_s1d2, 0);
+ test_path(_metadata, file1_s1d2, 0);
+ test_path(_metadata, dir_s1d3, 0);
+ test_path(_metadata, file1_s1d3, 0);
+
+ /* Tests on a file. */
+ test_path(_metadata, dir_s2d2, -1);
+ test_path(_metadata, file1_s2d2, 0);
+
+ /* Checks effective read and write actions. */
+ reg_fd = open(file1_s2d2, O_RDWR | O_CLOEXEC);
+ ASSERT_LE(0, reg_fd);
+ ASSERT_EQ(1, write(reg_fd, ".", 1));
+ ASSERT_LE(0, lseek(reg_fd, 0, SEEK_SET));
+ ASSERT_EQ(1, read(reg_fd, &buf, 1));
+ ASSERT_EQ('.', buf);
+ ASSERT_EQ(0, close(reg_fd));
+
+ /* Just in case, double-checks effective actions. */
+ reg_fd = open(file1_s2d2, O_RDONLY | O_CLOEXEC);
+ ASSERT_LE(0, reg_fd);
+ ASSERT_EQ(-1, write(reg_fd, &buf, 1));
+ ASSERT_EQ(EBADF, errno);
+ ASSERT_EQ(0, close(reg_fd));
+}
+
+TEST_F(layout1, unhandled_access)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ /* Here, we only handle read accesses, not write accesses. */
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules);
+ int file_fd;
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /*
+ * Because the policy does not handle LANDLOCK_ACCESS_FS_WRITE_FILE,
+ * opening for write-only should be allowed, but not read-write.
+ */
+ file_fd = open(file1_s1d1, O_WRONLY | O_CLOEXEC);
+ ASSERT_LE(0, file_fd);
+ EXPECT_EQ(0, close(file_fd));
+ ASSERT_EQ(-1, open(file1_s1d1, O_RDWR | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ file_fd = open(file1_s1d2, O_WRONLY | O_CLOEXEC);
+ ASSERT_LE(0, file_fd);
+ EXPECT_EQ(0, close(file_fd));
+ file_fd = open(file1_s1d2, O_RDWR | O_CLOEXEC);
+ ASSERT_LE(0, file_fd);
+ EXPECT_EQ(0, close(file_fd));
+}
+
+TEST_F(layout1, ruleset_overlap)
+{
+ const struct rule rules[] = {
+ /* These rules should be ORed among them. */
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_WRITE_FILE,
+ },
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_READ_DIR,
+ },
+ {}
+ };
+ int open_fd;
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, open(file1_s1d1, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, open(dir_s1d1, O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ open_fd = open(file1_s1d2, O_WRONLY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ EXPECT_EQ(0, close(open_fd));
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ EXPECT_EQ(0, close(open_fd));
+
+ open_fd = open(file1_s1d3, O_WRONLY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ EXPECT_EQ(0, close(open_fd));
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ EXPECT_EQ(0, close(open_fd));
+}
+
+TEST_F(layout1, inherit_subset)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_READ_DIR,
+ },
+ {}
+ };
+ int open_fd;
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ ASSERT_EQ(-1, open(file1_s1d1, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, open(dir_s1d1, O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ /* Write access is forbidden. */
+ ASSERT_EQ(-1, open(file1_s1d2, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is allowed. */
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /* Write access is forbidden. */
+ ASSERT_EQ(-1, open(file1_s1d3, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is allowed. */
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /*
+ * Tests shared rule extension: the following rules should not grant
+ * any new access, only remove some. Once enforced, these rules are
+ * ANDed with the previous ones.
+ */
+ add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_WRITE_FILE,
+ dir_s1d2);
+ /*
+ * According to ruleset_fd, dir_s1d2 should now have the
+ * LANDLOCK_ACCESS_FS_READ_FILE and LANDLOCK_ACCESS_FS_WRITE_FILE
+ * access rights (even if this directory is opened a second time).
+ * However, when enforcing this updated ruleset, the ruleset tied to
+ * the current process (i.e. its domain) will still only have the
+ * dir_s1d2 with LANDLOCK_ACCESS_FS_READ_FILE and
+ * LANDLOCK_ACCESS_FS_READ_DIR accesses, but
+ * LANDLOCK_ACCESS_FS_WRITE_FILE must not be allowed because it would
+ * be a privilege escalation.
+ */
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ /* Same tests and results as above. */
+ ASSERT_EQ(-1, open(file1_s1d1, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, open(dir_s1d1, O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ /* It is still forbidden to write in file1_s1d2. */
+ ASSERT_EQ(-1, open(file1_s1d2, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is still allowed. */
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /* It is still forbidden to write in file1_s1d3. */
+ ASSERT_EQ(-1, open(file1_s1d3, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is still allowed. */
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /*
+ * Try to get more privileges by adding new access rights to the parent
+ * directory: dir_s1d1.
+ */
+ add_path_beneath(_metadata, ruleset_fd, ACCESS_RW, dir_s1d1);
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ /* Same tests and results as above. */
+ ASSERT_EQ(-1, open(file1_s1d1, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, open(dir_s1d1, O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ /* It is still forbidden to write in file1_s1d2. */
+ ASSERT_EQ(-1, open(file1_s1d2, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is still allowed. */
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /* It is still forbidden to write in file1_s1d3. */
+ ASSERT_EQ(-1, open(file1_s1d3, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is still allowed. */
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /*
+ * Now, dir_s1d3 get a new rule tied to it, only allowing
+ * LANDLOCK_ACCESS_FS_WRITE_FILE. The (kernel internal) difference is
+ * that there was no rule tied to it before.
+ */
+ add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_WRITE_FILE,
+ dir_s1d3);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /*
+ * Same tests and results as above, except for open(dir_s1d3) which is
+ * now denied because the new rule mask the rule previously inherited
+ * from dir_s1d2.
+ */
+
+ /* Same tests and results as above. */
+ ASSERT_EQ(-1, open(file1_s1d1, O_WRONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, open(dir_s1d1, O_RDONLY | O_DIRECTORY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ /* It is still forbidden to write in file1_s1d2. */
+ ASSERT_EQ(-1, open(file1_s1d2, O_WRONLY | O_CLOEXEC));
+ /* Readdir access is still allowed. */
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /* It is still forbidden to write in file1_s1d3. */
+ ASSERT_EQ(-1, open(file1_s1d3, O_WRONLY | O_CLOEXEC));
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ /* Readdir of dir_s1d3 is now forbidden too. */
+ ASSERT_EQ(-1, open_fd);
+ ASSERT_EQ(EACCES, errno);
+}
+
+TEST_F(layout1, inherit_superset)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d3,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ int open_fd;
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ /* Readdir access is denied for dir_s1d2. */
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_EQ(-1, open_fd);
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is allowed for dir_s1d3. */
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /* Now dir_s1d2, parent of dir_s1d3, gets a new rule tied to it. */
+ add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_READ_DIR, dir_s1d2);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /* Readdir access is still denied for dir_s1d2. */
+ open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_EQ(-1, open_fd);
+ ASSERT_EQ(EACCES, errno);
+ /* Readdir access is still allowed for dir_s1d3. */
+ open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_LE(0, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+}
+
+TEST_F(layout1, max_layers)
+{
+ int i, err;
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ for (i = 0; i < 64; i++)
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ for (i = 0; i < 2; i++) {
+ err = landlock_enforce_ruleset_current(ruleset_fd, 0);
+ ASSERT_EQ(-1, err);
+ ASSERT_EQ(E2BIG, errno);
+ }
+ EXPECT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(layout1, empty_or_same_ruleset)
+{
+ struct landlock_ruleset_attr ruleset_attr = {};
+ int ruleset_fd;
+
+ /* Tests empty handled_access_fs. */
+ ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+ ASSERT_LE(-1, ruleset_fd);
+ ASSERT_EQ(ENOMSG, errno);
+
+ /* Enforces policy which deny read access to all files. */
+ ruleset_attr.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE;
+ ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ test_path(_metadata, file1_s1d1, -1);
+ test_path(_metadata, dir_s1d1, 0);
+
+ /* Nests a policy which deny read access to all directories. */
+ ruleset_attr.handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR;
+ ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ test_path(_metadata, file1_s1d1, -1);
+ test_path(_metadata, dir_s1d1, -1);
+
+ /* Enforces a second time with the same ruleset. */
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(layout1, rule_on_mountpoint)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d1,
+ .access = ACCESS_RO,
+ },
+ {
+ /* dir_s3d2 is a mount point. */
+ .path = dir_s3d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, dir_s1d1, 0);
+
+ test_path(_metadata, dir_s2d1, -1);
+
+ test_path(_metadata, dir_s3d1, -1);
+ test_path(_metadata, dir_s3d2, 0);
+ test_path(_metadata, dir_s3d3, 0);
+}
+
+TEST_F(layout1, rule_over_mountpoint)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d1,
+ .access = ACCESS_RO,
+ },
+ {
+ /* dir_s3d2 is a mount point. */
+ .path = dir_s3d1,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, dir_s1d1, 0);
+
+ test_path(_metadata, dir_s2d1, -1);
+
+ test_path(_metadata, dir_s3d1, 0);
+ test_path(_metadata, dir_s3d2, 0);
+ test_path(_metadata, dir_s3d3, 0);
+}
+
+/*
+ * This test verifies that we can apply a landlock rule on the root (/), it
+ * might require special handling.
+ */
+TEST_F(layout1, rule_over_root)
+{
+ const struct rule rules[] = {
+ {
+ .path = "/",
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, "/", 0);
+ test_path(_metadata, dir_s1d1, 0);
+}
+
+TEST_F(layout1, rule_inside_mount_ns)
+{
+ const struct rule rules[] = {
+ {
+ .path = "s3d3",
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ int ruleset_fd;
+
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ ASSERT_EQ(0, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL));
+ ASSERT_EQ(0, syscall(SYS_pivot_root, dir_s3d2, dir_s3d3)) {
+ TH_LOG("Failed to pivot_root into \"%s\": %s", dir_s3d2,
+ strerror(errno));
+ };
+ ASSERT_EQ(0, chdir("/"));
+ clear_cap(_metadata, CAP_SYS_ADMIN);
+
+ ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, "s3d3", 0);
+ test_path(_metadata, "/", -1);
+}
+
+TEST_F(layout1, mount_and_pivot)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s3d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ ASSERT_EQ(0, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL));
+ ASSERT_EQ(EPERM, errno);
+ ASSERT_EQ(-1, syscall(SYS_pivot_root, dir_s3d2, dir_s3d3));
+ ASSERT_EQ(EPERM, errno);
+}
+
+TEST_F(layout1, move_mount)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s3d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ ASSERT_EQ(0, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL));
+ ASSERT_EQ(0, syscall(SYS_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
+ dir_s1d2, 0)) {
+ TH_LOG("Failed to move_mount: %s", strerror(errno));
+ }
+ ASSERT_EQ(0, syscall(SYS_move_mount, AT_FDCWD, dir_s1d2, AT_FDCWD,
+ dir_s3d2, 0));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, syscall(SYS_move_mount, AT_FDCWD, dir_s3d2, AT_FDCWD,
+ dir_s1d2, 0));
+ ASSERT_EQ(EPERM, errno);
+}
+
+TEST_F(layout1, release_inodes)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d1,
+ .access = ACCESS_RO,
+ },
+ {
+ .path = dir_s3d2,
+ .access = ACCESS_RO,
+ },
+ {
+ .path = dir_s3d3,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+ int test_fd;
+
+ ASSERT_LE(0, ruleset_fd);
+ /* Unmount a file hierarchy while it is being used by a ruleset. */
+ set_cap(_metadata, CAP_SYS_ADMIN);
+ ASSERT_EQ(0, umount(dir_s3d2));
+ clear_cap(_metadata, CAP_SYS_ADMIN);
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_fd = open(file1_s1d1, O_RDONLY | O_CLOEXEC);
+ ASSERT_LE(0, test_fd);
+ /* This dir_s3d2 is not allowed, only the tmpfs on it was. */
+ ASSERT_EQ(-1, open(dir_s3d2, O_RDONLY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ /* This dir_s3d3 would not be allowed and does not exist anyway. */
+ ASSERT_EQ(-1, open(dir_s3d3, O_RDONLY | O_CLOEXEC));
+ ASSERT_EQ(ENOENT, errno);
+}
+
+enum relative_access {
+ REL_OPEN,
+ REL_CHDIR,
+ REL_CHROOT_ONLY,
+ REL_CHROOT_CHDIR,
+};
+
+static void test_relative_path(struct __test_metadata *const _metadata,
+ const enum relative_access rel)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = ACCESS_RO,
+ },
+ {
+ .path = dir_s2d2,
+ .access = ACCESS_RO,
+ },
+ {}
+ };
+ int dirfd;
+ const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ switch (rel) {
+ case REL_OPEN:
+ case REL_CHDIR:
+ break;
+ case REL_CHROOT_ONLY:
+ ASSERT_EQ(0, chdir(dir_s2d2));
+ break;
+ case REL_CHROOT_CHDIR:
+ ASSERT_EQ(0, chdir(dir_s1d2));
+ break;
+ default:
+ ASSERT_TRUE(false);
+ return;
+ }
+
+ set_cap(_metadata, CAP_SYS_CHROOT);
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ switch (rel) {
+ case REL_OPEN:
+ dirfd = open(dir_s1d2, O_DIRECTORY);
+ ASSERT_LE(0, dirfd);
+ break;
+ case REL_CHDIR:
+ ASSERT_EQ(0, chdir(dir_s1d2));
+ dirfd = AT_FDCWD;
+ break;
+ case REL_CHROOT_ONLY:
+ /* Do chroot into dir_s1d2 (relative to dir_s2d2). */
+ ASSERT_EQ(0, chroot("../../s1d1/s1d2")) {
+ TH_LOG("Failed to chroot: %s", strerror(errno));
+ }
+ dirfd = AT_FDCWD;
+ break;
+ case REL_CHROOT_CHDIR:
+ /* Do chroot into dir_s1d2. */
+ ASSERT_EQ(0, chroot(".")) {
+ TH_LOG("Failed to chroot: %s", strerror(errno));
+ }
+ dirfd = AT_FDCWD;
+ break;
+ }
+
+ test_path_rel(_metadata, dirfd, "..",
+ (rel == REL_CHROOT_CHDIR) ? 0 : -1);
+ test_path_rel(_metadata, dirfd, ".", 0);
+
+ if (rel == REL_CHROOT_ONLY)
+ /* The current directory is dir_s2d2. */
+ test_path_rel(_metadata, dirfd, "./s2d3", 0);
+ else
+ /* The current directory is dir_s1d2. */
+ test_path_rel(_metadata, dirfd, "./s1d3", 0);
+
+ if (rel != REL_CHROOT_CHDIR) {
+ test_path_rel(_metadata, dirfd, "../../s1d1", -1);
+ test_path_rel(_metadata, dirfd, "../../s1d1/s1d2", 0);
+ test_path_rel(_metadata, dirfd, "../../s1d1/s1d2/s1d3", 0);
+
+ test_path_rel(_metadata, dirfd, "../../s2d1", -1);
+ test_path_rel(_metadata, dirfd, "../../s2d1/s2d2", 0);
+ test_path_rel(_metadata, dirfd, "../../s2d1/s2d2/s2d3", 0);
+ }
+
+ if (rel == REL_OPEN)
+ EXPECT_EQ(0, close(dirfd));
+ EXPECT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(layout1, relative_open)
+{
+ test_relative_path(_metadata, REL_OPEN);
+}
+
+TEST_F(layout1, relative_chdir)
+{
+ test_relative_path(_metadata, REL_CHDIR);
+}
+
+TEST_F(layout1, relative_chroot_only)
+{
+ test_relative_path(_metadata, REL_CHROOT_ONLY);
+}
+
+TEST_F(layout1, relative_chroot_chdir)
+{
+ test_relative_path(_metadata, REL_CHROOT_CHDIR);
+}
+
+static void copy_binary(struct __test_metadata *const _metadata,
+ const char *const dst_path)
+{
+ int dst_fd, src_fd;
+ struct stat statbuf;
+
+ dst_fd = open(dst_path, O_WRONLY | O_TRUNC | O_CLOEXEC);
+ ASSERT_LE(0, dst_fd) {
+ TH_LOG("Failed to open \"%s\": %s", dst_path,
+ strerror(errno));
+ }
+ src_fd = open(BINARY_PATH, O_RDONLY | O_CLOEXEC);
+ ASSERT_LE(0, src_fd) {
+ TH_LOG("Failed to open \"" BINARY_PATH "\": %s",
+ strerror(errno));
+ }
+ ASSERT_EQ(0, fstat(src_fd, &statbuf));
+ ASSERT_EQ(statbuf.st_size, sendfile(dst_fd, src_fd, 0,
+ statbuf.st_size));
+ ASSERT_EQ(0, close(src_fd));
+ ASSERT_EQ(0, close(dst_fd));
+}
+
+static void test_execute(struct __test_metadata *const _metadata,
+ const char *const path, const int ret)
+{
+ int status;
+ char *const argv[] = {(char *)path, NULL};
+ const pid_t child = fork();
+
+ ASSERT_LE(0, child);
+ if (child == 0) {
+ ASSERT_EQ(ret, execve(path, argv, NULL)) {
+ TH_LOG("Failed to execute \"%s\": %s", path,
+ strerror(errno));
+ };
+ ASSERT_EQ(EACCES, errno);
+ _exit(_metadata->passed ? 2 : 1);
+ return;
+ }
+ ASSERT_EQ(child, waitpid(child, &status, 0));
+ ASSERT_EQ(1, WIFEXITED(status));
+ ASSERT_EQ(ret ? 2 : 0, WEXITSTATUS(status)) {
+ TH_LOG("Unexpected return code for \"%s\": %s", path,
+ strerror(errno));
+ };
+}
+
+TEST_F(layout1, execute)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_EXECUTE,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ copy_binary(_metadata, file1_s1d1);
+ copy_binary(_metadata, file1_s1d2);
+ copy_binary(_metadata, file1_s1d3);
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_execute(_metadata, file1_s1d1, -1);
+ test_execute(_metadata, file1_s1d2, 0);
+ test_execute(_metadata, file1_s1d3, 0);
+}
+
+TEST_F(layout1, link)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_MAKE_REG,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ ASSERT_EQ(0, unlink(file1_s1d1));
+ ASSERT_EQ(0, unlink(file1_s1d2));
+ ASSERT_EQ(0, unlink(file1_s1d3));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, link(file2_s1d1, file1_s1d1));
+ ASSERT_EQ(EACCES, errno);
+ /* Denies linking because of reparenting. */
+ ASSERT_EQ(-1, link(file1_s2d1, file1_s1d2));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, link(file2_s1d2, file1_s1d3));
+ ASSERT_EQ(EACCES, errno);
+
+ ASSERT_EQ(0, link(file2_s1d2, file1_s1d2)) {
+ TH_LOG("Failed to link file to \"%s\": %s", file2_s1d2,
+ strerror(errno));
+ };
+ ASSERT_EQ(0, link(file2_s1d3, file1_s1d3));
+}
+
+TEST_F(layout1, rename_file)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d3,
+ .access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
+ },
+ {
+ .path = dir_s2d2,
+ .access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ ASSERT_EQ(0, unlink(file1_s1d1));
+ ASSERT_EQ(0, unlink(file1_s1d2));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /* Replaces file. */
+ ASSERT_EQ(-1, rename(file1_s2d3, file1_s1d3));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
+ ASSERT_EQ(EACCES, errno);
+ /* Same parent. */
+ ASSERT_EQ(0, rename(file2_s2d3, file1_s2d3)) {
+ TH_LOG("Failed to rename file \"%s\": %s", file2_s2d3,
+ strerror(errno));
+ };
+
+ /* Renames files. */
+ ASSERT_EQ(-1, rename(file1_s2d2, file1_s1d2));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, unlink(file1_s1d3));
+ ASSERT_EQ(-1, rename(file1_s2d1, file1_s1d3));
+ ASSERT_EQ(EACCES, errno);
+ /* Same parent. */
+ ASSERT_EQ(0, rename(file2_s1d3, file1_s1d3));
+}
+
+TEST_F(layout1, rename_dir)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
+ },
+ {
+ .path = dir_s2d1,
+ .access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ /* Empties dir_s1d3. */
+ ASSERT_EQ(0, unlink(file1_s1d3));
+ ASSERT_EQ(0, unlink(file2_s1d3));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /* Renames directory. */
+ ASSERT_EQ(-1, rename(dir_s2d3, dir_s1d3));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, unlink(file1_s1d2));
+ ASSERT_EQ(0, rename(dir_s1d3, file1_s1d2)) {
+ TH_LOG("Failed to rename directory \"%s\": %s", dir_s1d3,
+ strerror(errno));
+ };
+ ASSERT_EQ(0, rmdir(file1_s1d2));
+}
+
+TEST_F(layout1, rmdir)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_REMOVE_DIR,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ ASSERT_EQ(0, unlink(file1_s1d1));
+ ASSERT_EQ(0, unlink(file1_s1d2));
+ ASSERT_EQ(0, unlink(file1_s1d3));
+ ASSERT_EQ(0, unlink(file2_s1d3));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(0, rmdir(dir_s1d3));
+ /* dir_s1d2 itself cannot be removed. */
+ ASSERT_EQ(-1, rmdir(dir_s1d2));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(-1, rmdir(dir_s1d1));
+ ASSERT_EQ(EACCES, errno);
+}
+
+TEST_F(layout1, unlink)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_REMOVE_FILE,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, unlink(file1_s1d1));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, unlink(file1_s1d2)) {
+ TH_LOG("Failed to unlink file \"%s\": %s", file1_s1d2,
+ strerror(errno));
+ };
+ ASSERT_EQ(0, unlink(file1_s1d3));
+}
+
+static void test_make_file(struct __test_metadata *const _metadata,
+ const __u64 access, const mode_t mode, const dev_t dev)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = access,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, access, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ unlink(file1_s1d1);
+ unlink(file1_s1d2);
+ unlink(file1_s1d3);
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, mknod(file1_s1d1, mode | 0400, dev));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, mknod(file1_s1d2, mode | 0400, dev)) {
+ TH_LOG("Failed to make file \"%s\": %s",
+ file1_s1d2, strerror(errno));
+ };
+ ASSERT_EQ(0, mknod(file1_s1d3, mode | 0400, dev));
+}
+
+TEST_F(layout1, make_char)
+{
+ /* Creates a /dev/null device. */
+ set_cap(_metadata, CAP_MKNOD);
+ test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_CHAR, S_IFCHR,
+ makedev(1, 3));
+}
+
+TEST_F(layout1, make_block)
+{
+ /* Creates a /dev/loop0 device. */
+ set_cap(_metadata, CAP_MKNOD);
+ test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_BLOCK, S_IFBLK,
+ makedev(7, 0));
+}
+
+TEST_F(layout1, make_reg)
+{
+ test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, S_IFREG, 0);
+ test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_REG, 0, 0);
+}
+
+TEST_F(layout1, make_sock)
+{
+ test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_SOCK, S_IFSOCK, 0);
+}
+
+TEST_F(layout1, make_fifo)
+{
+ test_make_file(_metadata, LANDLOCK_ACCESS_FS_MAKE_FIFO, S_IFIFO, 0);
+}
+
+TEST_F(layout1, make_sym)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_MAKE_SYM,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ ASSERT_EQ(0, unlink(file1_s1d1));
+ ASSERT_EQ(0, unlink(file1_s1d2));
+ ASSERT_EQ(0, unlink(file1_s1d3));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, symlink("none", file1_s1d1));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, symlink("none", file1_s1d2)) {
+ TH_LOG("Failed to make symlink \"%s\": %s",
+ file1_s1d2, strerror(errno));
+ };
+ ASSERT_EQ(0, symlink("none", file1_s1d3));
+}
+
+TEST_F(layout1, make_dir)
+{
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_MAKE_DIR,
+ },
+ {}
+ };
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+
+ ASSERT_EQ(0, unlink(file1_s1d1));
+ ASSERT_EQ(0, unlink(file1_s1d2));
+ ASSERT_EQ(0, unlink(file1_s1d3));
+
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /* Uses file_* as directory names. */
+ ASSERT_EQ(-1, mkdir(file1_s1d1, 0700));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, mkdir(file1_s1d2, 0700)) {
+ TH_LOG("Failed to make directory \"%s\": %s",
+ file1_s1d2, strerror(errno));
+ };
+ ASSERT_EQ(0, mkdir(file1_s1d3, 0700));
+}
+
+static int open_proc_fd(struct __test_metadata *const _metadata, const int fd,
+ const int open_flags)
+{
+ static const char path_template[] = "/proc/self/fd/%d";
+ char procfd_path[sizeof(path_template) + 10];
+ const int procfd_path_size = snprintf(procfd_path, sizeof(procfd_path),
+ path_template, fd);
+
+ ASSERT_LT(procfd_path_size, sizeof(procfd_path));
+ return open(procfd_path, open_flags);
+}
+
+TEST_F(layout1, proc_unlinked_file)
+{
+ const struct rule rules[] = {
+ {
+ .path = file1_s1d2,
+ .access = LANDLOCK_ACCESS_FS_READ_FILE,
+ },
+ {}
+ };
+ int reg_fd, proc_fd;
+ const int ruleset_fd = create_ruleset(_metadata,
+ LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE, rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, open(file1_s1d2, O_RDWR | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+ reg_fd = open(file1_s1d2, O_RDONLY | O_CLOEXEC);
+ ASSERT_LE(0, reg_fd);
+ test_path(_metadata, file1_s1d2, 0);
+ ASSERT_EQ(0, unlink(file1_s1d2));
+
+ proc_fd = open_proc_fd(_metadata, reg_fd, O_RDONLY | O_CLOEXEC);
+ ASSERT_LE(0, proc_fd);
+ EXPECT_EQ(0, close(proc_fd));
+
+ proc_fd = open_proc_fd(_metadata, reg_fd, O_RDWR | O_CLOEXEC);
+ ASSERT_EQ(-1, proc_fd) {
+ TH_LOG("Successfully opened /proc/self/fd/%d: %s",
+ reg_fd, strerror(errno));
+ }
+ ASSERT_EQ(EACCES, errno);
+
+ EXPECT_EQ(0, close(reg_fd));
+}
+
+TEST_F(layout1, proc_pipe)
+{
+ int reg_fd, proc_fd;
+ int pipe_fds[2];
+ char buf = '\0';
+ const struct rule rules[] = {
+ {
+ .path = dir_s1d2,
+ .access = LANDLOCK_ACCESS_FS_READ_FILE |
+ LANDLOCK_ACCESS_FS_WRITE_FILE,
+ },
+ {}
+ };
+ /* Limits read and write access to files tied to the filesystem. */
+ const int ruleset_fd = create_ruleset(_metadata, rules[0].access,
+ rules);
+
+ ASSERT_LE(0, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /* Checks enforcement for normal files. */
+ reg_fd = open(file1_s1d2, O_RDWR | O_CLOEXEC);
+ ASSERT_LE(0, reg_fd);
+ EXPECT_EQ(0, close(reg_fd));
+ ASSERT_EQ(-1, open(file1_s1d1, O_RDWR | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ /* Checks access to pipes through FD. */
+ ASSERT_EQ(0, pipe(pipe_fds));
+ ASSERT_EQ(1, write(pipe_fds[1], ".", 1)) {
+ TH_LOG("Failed to write in pipe: %s", strerror(errno));
+ }
+ ASSERT_EQ(1, read(pipe_fds[0], &buf, 1));
+ ASSERT_EQ('.', buf);
+
+ /* Checks write access to pipe through /proc/self/fd . */
+ proc_fd = open_proc_fd(_metadata, pipe_fds[1], O_WRONLY | O_CLOEXEC);
+ ASSERT_LE(0, proc_fd);
+ ASSERT_EQ(1, write(proc_fd, ".", 1)) {
+ TH_LOG("Failed to write through /proc/self/fd/%d: %s",
+ pipe_fds[1], strerror(errno));
+ }
+ EXPECT_EQ(0, close(proc_fd));
+
+ /* Checks read access to pipe through /proc/self/fd . */
+ proc_fd = open_proc_fd(_metadata, pipe_fds[0], O_RDONLY | O_CLOEXEC);
+ ASSERT_LE(0, proc_fd);
+ buf = '\0';
+ ASSERT_EQ(1, read(proc_fd, &buf, 1)) {
+ TH_LOG("Failed to read through /proc/self/fd/%d: %s",
+ pipe_fds[1], strerror(errno));
+ }
+ EXPECT_EQ(0, close(proc_fd));
+
+ EXPECT_EQ(0, close(pipe_fds[0]));
+ EXPECT_EQ(0, close(pipe_fds[1]));
+}
+
+TEST(cleanup)
+{
+ cleanup_layout1(_metadata);
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/landlock/ptrace_test.c
b/tools/testing/selftests/landlock/ptrace_test.c
new file mode 100644
index 000000000000..f1451b305181
--- /dev/null
+++ b/tools/testing/selftests/landlock/ptrace_test.c
@@ -0,0 +1,307 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Landlock tests - Ptrace
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <m...@digikod.net>
+ * Copyright © 2019-2020 ANSSI
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/landlock.h>
+#include <signal.h>
+#include <sys/prctl.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "common.h"
+
+static void create_domain(struct __test_metadata *const _metadata)
+{
+ int ruleset_fd;
+ struct landlock_ruleset_attr ruleset_attr = {
+ .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
+ };
+ struct landlock_path_beneath_attr path_beneath_attr = {
+ .allowed_access = LANDLOCK_ACCESS_FS_READ_FILE,
+ };
+
+ ruleset_fd = landlock_create_ruleset(&ruleset_attr,
+ sizeof(ruleset_attr), 0);
+ ASSERT_LE(0, ruleset_fd) {
+ TH_LOG("Failed to create a ruleset: %s", strerror(errno));
+ }
+ 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, LANDLOCK_RULE_PATH_BENEATH,
+ &path_beneath_attr, 0));
+ ASSERT_EQ(0, errno);
+ ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
+
+ ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
+ ASSERT_EQ(0, errno);
+
+ ASSERT_EQ(0, landlock_enforce_ruleset_current(ruleset_fd, 0));
+ ASSERT_EQ(0, errno);
+
+ ASSERT_EQ(0, close(ruleset_fd));
+}
+
+FIXTURE(hierarchy) { };
+
+FIXTURE_VARIANT(hierarchy) {
+ const bool domain_both;
+ const bool domain_parent;
+ const bool domain_child;
+};
+
+/*
+ * Test multiple tracing combinations between a parent process P1 and a child
+ * process P2.
+ *
+ * Yama's scoped ptrace is presumed disabled. If enabled, this optional
+ * restriction is enforced in addition to any Landlock check, which means that
+ * all P2 requests to trace P1 would be denied.
+ */
+
+/*
+ * No domain
+ *
+ * P1-. P1 -> P2 : allow
+ * \ P2 -> P1 : allow
+ * 'P2
+ */
+FIXTURE_VARIANT_ADD(hierarchy, allow_without_domain) {
+ .domain_both = false,
+ .domain_parent = false,
+ .domain_child = false,
+};
+
+/*
+ * Child domain
+ *
+ * P1--. P1 -> P2 : allow
+ * \ P2 -> P1 : deny
+ * .'-----.
+ * | P2 |
+ * '------'
+ */
+FIXTURE_VARIANT_ADD(hierarchy, allow_with_one_domain) {
+ .domain_both = false,
+ .domain_parent = false,
+ .domain_child = true,
+};
+
+/*
+ * Parent domain
+ * .------.
+ * | P1 --. P1 -> P2 : deny
+ * '------' \ P2 -> P1 : allow
+ * '
+ * P2
+ */
+FIXTURE_VARIANT_ADD(hierarchy, deny_with_parent_domain) {
+ .domain_both = false,
+ .domain_parent = true,
+ .domain_child = false,
+};
+
+/*
+ * Parent + child domain (siblings)
+ * .------.
+ * | P1 ---. P1 -> P2 : deny
+ * '------' \ P2 -> P1 : deny
+ * .---'--.
+ * | P2 |
+ * '------'
+ */
+FIXTURE_VARIANT_ADD(hierarchy, deny_with_sibling_domain) {
+ .domain_both = false,
+ .domain_parent = true,
+ .domain_child = true,
+};
+
+/*
+ * Same domain (inherited)
+ * .-------------.
+ * | P1----. | P1 -> P2 : allow
+ * | \ | P2 -> P1 : allow
+ * | ' |
+ * | P2 |
+ * '-------------'
+ */
+FIXTURE_VARIANT_ADD(hierarchy, allow_sibling_domain) {
+ .domain_both = true,
+ .domain_parent = false,
+ .domain_child = false,
+};
+
+/*
+ * Inherited + child domain
+ * .-----------------.
+ * | P1----. | P1 -> P2 : allow
+ * | \ | P2 -> P1 : deny
+ * | .-'----. |
+ * | | P2 | |
+ * | '------' |
+ * '-----------------'
+ */
+FIXTURE_VARIANT_ADD(hierarchy, allow_with_nested_domain) {
+ .domain_both = true,
+ .domain_parent = false,
+ .domain_child = true,
+};
+
+/*
+ * Inherited + parent domain
+ * .-----------------.
+ * |.------. | P1 -> P2 : deny
+ * || P1 ----. | P2 -> P1 : allow
+ * |'------' \ |
+ * | ' |
+ * | P2 |
+ * '-----------------'
+ */
+FIXTURE_VARIANT_ADD(hierarchy, deny_with_nested_and_parent_domain) {
+ .domain_both = true,
+ .domain_parent = true,
+ .domain_child = false,
+};
+
+/*
+ * Inherited + parent and child domain (siblings)
+ * .-----------------.
+ * | .------. | P1 -> P2 : deny
+ * | | P1 . | P2 -> P1 : deny
+ * | '------'\ |
+ * | \ |
+ * | .--'---. |
+ * | | P2 | |
+ * | '------' |
+ * '-----------------'
+ */
+FIXTURE_VARIANT_ADD(hierarchy, deny_with_forked_domain) {
+ .domain_both = true,
+ .domain_parent = true,
+ .domain_child = true,
+};
+
+FIXTURE_SETUP(hierarchy)
+{ }
+
+FIXTURE_TEARDOWN(hierarchy)
+{ }
+
+/* test PTRACE_TRACEME and PTRACE_ATTACH for parent and child */
+TEST_F(hierarchy, trace)
+{
+ pid_t child, parent;
+ int status;
+ int pipe_child[2], pipe_parent[2];
+ char buf_parent;
+
+ disable_caps(_metadata);
+
+ parent = getpid();
+ ASSERT_EQ(0, pipe(pipe_child));
+ ASSERT_EQ(0, pipe(pipe_parent));
+ if (variant->domain_both)
+ create_domain(_metadata);
+
+ child = fork();
+ ASSERT_LE(0, child);
+ if (child == 0) {
+ char buf_child;
+
+ EXPECT_EQ(0, close(pipe_parent[1]));
+ EXPECT_EQ(0, close(pipe_child[0]));
+ if (variant->domain_child)
+ create_domain(_metadata);
+
+ /* sync #1 */
+ ASSERT_EQ(1, read(pipe_parent[0], &buf_child, 1)) {
+ TH_LOG("Failed to read() sync #1 from parent");
+ }
+ ASSERT_EQ('.', buf_child);
+
+ /* Tests the parent protection. */
+ ASSERT_EQ(variant->domain_child ? -1 : 0,
+ ptrace(PTRACE_ATTACH, parent, NULL, 0));
+ if (variant->domain_child) {
+ ASSERT_EQ(EPERM, errno);
+ } else {
+ ASSERT_EQ(parent, waitpid(parent, &status, 0));
+ ASSERT_EQ(1, WIFSTOPPED(status));
+ ASSERT_EQ(0, ptrace(PTRACE_DETACH, parent, NULL, 0));
+ }
+
+ /* sync #2 */
+ ASSERT_EQ(1, write(pipe_child[1], ".", 1)) {
+ TH_LOG("Failed to write() sync #2 to parent");
+ }
+
+ /* Tests traceme. */
+ ASSERT_EQ(variant->domain_parent ? -1 : 0,
+ ptrace(PTRACE_TRACEME));
+ if (variant->domain_parent) {
+ ASSERT_EQ(EPERM, errno);
+ } else {
+ ASSERT_EQ(0, raise(SIGSTOP));
+ }
+
+ /* sync #3 */
+ ASSERT_EQ(1, read(pipe_parent[0], &buf_child, 1)) {
+ TH_LOG("Failed to read() sync #3 from parent");
+ }
+ ASSERT_EQ('.', buf_child);
+ _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
+ }
+
+ EXPECT_EQ(0, close(pipe_child[1]));
+ EXPECT_EQ(0, close(pipe_parent[0]));
+ if (variant->domain_parent)
+ create_domain(_metadata);
+
+ /* sync #1 */
+ ASSERT_EQ(1, write(pipe_parent[1], ".", 1)) {
+ TH_LOG("Failed to write() sync #1 to child");
+ }
+
+ /* Tests the parent protection. */
+ /* sync #2 */
+ ASSERT_EQ(1, read(pipe_child[0], &buf_parent, 1)) {
+ TH_LOG("Failed to read() sync #2 from child");
+ }
+ ASSERT_EQ('.', buf_parent);
+
+ /* Tests traceme. */
+ if (!variant->domain_parent) {
+ ASSERT_EQ(child, waitpid(child, &status, 0));
+ ASSERT_EQ(1, WIFSTOPPED(status));
+ ASSERT_EQ(0, ptrace(PTRACE_DETACH, child, NULL, 0));
+ }
+ /* Tests attach. */
+ ASSERT_EQ(variant->domain_parent ? -1 : 0,
+ ptrace(PTRACE_ATTACH, child, NULL, 0));
+ if (variant->domain_parent) {
+ ASSERT_EQ(EPERM, errno);
+ } else {
+ ASSERT_EQ(child, waitpid(child, &status, 0));
+ ASSERT_EQ(1, WIFSTOPPED(status));
+ ASSERT_EQ(0, ptrace(PTRACE_DETACH, child, NULL, 0));
+ }
+
+ /* sync #3 */
+ ASSERT_EQ(1, write(pipe_parent[1], ".", 1)) {
+ TH_LOG("Failed to write() sync #3 to child");
+ }
+ ASSERT_EQ(child, waitpid(child, &status, 0));
+ if (WIFSIGNALED(status) || WEXITSTATUS(status))
+ _metadata->passed = 0;
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/landlock/true.c
b/tools/testing/selftests/landlock/true.c
new file mode 100644
index 000000000000..3f9ccbf52783
--- /dev/null
+++ b/tools/testing/selftests/landlock/true.c
@@ -0,0 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0
+int main(void)
+{
+ return 0;
+}
--
2.28.0
