Test landlock syscall, ptrace hooks semantic and filesystem access-control.
Test coverage for security/landlock/ is 93.6% of lines. The code not covered only deals with internal kernel errors (e.g. memory allocation) and race conditions.
Signed-off-by: Mickaël Salaün mic@digikod.net Reviewed-by: Vincent Dagonneau vincent.dagonneau@ssi.gouv.fr Cc: James Morris jmorris@namei.org Cc: Jann Horn jannh@google.com Cc: Kees Cook keescook@chromium.org Cc: Serge E. Hallyn serge@hallyn.com Cc: Shuah Khan shuah@kernel.org ---
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-mic@digikod.net/ --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/landlock/.gitignore | 2 + tools/testing/selftests/landlock/Makefile | 29 + tools/testing/selftests/landlock/base_test.c | 163 ++ tools/testing/selftests/landlock/common.h | 108 + tools/testing/selftests/landlock/config | 5 + tools/testing/selftests/landlock/fs_test.c | 1730 +++++++++++++++++ .../testing/selftests/landlock/ptrace_test.c | 293 +++ tools/testing/selftests/landlock/true.c | 5 + 9 files changed, 2336 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 2ff68702fd41..725611ca8dfd 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -24,6 +24,7 @@ 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..d29bd0804c14 --- /dev/null +++ b/tools/testing/selftests/landlock/Makefile @@ -0,0 +1,29 @@ +# SPDX-License-Identifier: GPL-2.0 + +src_test := $(wildcard *_test.c) + +TEST_GEN_PROGS := $(src_test:.c=) + +TEST_GEN_PROGS_EXTENDED := true + +KSFT_KHDR_INSTALL := 1 +OVERRIDE_TARGETS := 1 +include ../lib.mk + +# Cf. tools/testing/selftests/arm64/Makefile +ifeq ($(KBUILD_OUTPUT),) +khdr_dir = $(top_srcdir)/usr/include +else +khdr_dir = $(KBUILD_OUTPUT)/kselftest/usr/include +endif + +CFLAGS += -Wall -O2 + +$(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..f6bc8d6419f8 --- /dev/null +++ b/tools/testing/selftests/landlock/base_test.c @@ -0,0 +1,163 @@ +// 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 "common.h" + +#ifndef O_PATH +#define O_PATH 010000000 +#endif + +TEST(features) +{ + struct landlock_attr_features attr_features; + + /* Tests that all fields are properly initialized. */ + memset(&attr_features, 0xff, sizeof(attr_features)); + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, + &attr_features, sizeof(attr_features))); + ASSERT_EQ(((LANDLOCK_OPT_GET_FEATURES << 1) - 1), + attr_features.options_get_features); + ASSERT_EQ(((LANDLOCK_OPT_CREATE_RULESET << 1) - 1), + attr_features.options_create_ruleset); + ASSERT_EQ(((LANDLOCK_OPT_ADD_RULE_PATH_BENEATH << 1) - 1), + attr_features.options_add_rule); + ASSERT_EQ(((LANDLOCK_OPT_ENFORCE_RULESET << 1) - 1), + attr_features.options_enforce_ruleset); + ASSERT_EQ(sizeof(struct landlock_attr_features), + attr_features.size_attr_features); + ASSERT_EQ(sizeof(struct landlock_attr_ruleset), + attr_features.size_attr_ruleset); + ASSERT_EQ(sizeof(struct landlock_attr_path_beneath), + attr_features.size_attr_path_beneath); + ASSERT_EQ(sizeof(struct landlock_attr_enforce), + attr_features.size_attr_enforce); + ASSERT_EQ(((LANDLOCK_ACCESS_FS_MAKE_SYM << 1) - 1), + attr_features.access_fs); +} + +TEST(inconsistent_attr) { + const long page_size = sysconf(_SC_PAGESIZE); + char *buf = malloc(page_size + 1); + + /* Checks copy_from_user(). */ + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, buf, 0)); + /* The size if less than sizeof(struct landlock_attr_enforce). */ + ASSERT_EQ(EINVAL, errno); + + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, NULL, 1)); + /* The size if less than sizeof(struct landlock_attr_enforce). */ + ASSERT_EQ(EINVAL, errno); + + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, + NULL, sizeof(struct landlock_attr_ruleset))); + ASSERT_EQ(EFAULT, errno); + + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, buf, page_size + 1)); + ASSERT_EQ(E2BIG, errno); + + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, buf, page_size)); + ASSERT_EQ(ENOMSG, errno); + + /* Checks non-zero value. */ + buf[page_size - 2] = '.'; + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, buf, page_size)); + ASSERT_EQ(E2BIG, errno); + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, buf, page_size + 1)); + ASSERT_EQ(E2BIG, errno); + + /* Checks copy_to_user(). */ + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, NULL, 0)); + ASSERT_EQ(ENODATA, errno); + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, buf, 0)); + ASSERT_EQ(ENODATA, errno); + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, buf, 1)); + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, buf, page_size + 1)); + ASSERT_EQ(E2BIG, errno); + ASSERT_EQ('.', buf[page_size - 2]); + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, buf, page_size)); + ASSERT_EQ('\0', buf[page_size - 2]); + + free(buf); +} + +TEST(empty_attr_ruleset) { + /* Similar to struct landlock_attr_ruleset.handled_access_fs = 0 */ + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, NULL, 0)); + ASSERT_EQ(EINVAL, errno); +} + +TEST(empty_attr_path_beneath) { + /* Similar to struct landlock_attr_path_beneath.*_fd = 0 */ + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, NULL, 0)); + ASSERT_EQ(EINVAL, errno); +} + +TEST(empty_attr_enforce) { + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); + + /* Similar to struct landlock_attr_enforce.ruleset_fd = 0 */ + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, NULL, 0)); + ASSERT_EQ(EINVAL, errno); +} + +TEST(unpriv_enforce_without_no_new_privs) { + int err; + + disable_caps(_metadata); + err = landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, NULL, 0); + ASSERT_EQ(errno, EPERM); + ASSERT_EQ(err, -1); +} + +TEST(ruleset_fd) +{ + struct landlock_attr_ruleset attr_ruleset = { + .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, + }; + int ruleset_fd; + char buf; + + disable_caps(_metadata); + ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + 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..51b727e9236e --- /dev/null +++ b/tools/testing/selftests/landlock/common.h @@ -0,0 +1,108 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Landlock test helpers + * + * Copyright © 2017-2020 Mickaël Salaün mic@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 landlock +static inline int landlock(const unsigned int command, + const unsigned int options, + void *const attr_ptr, const size_t attr_size) +{ + errno = 0; + return syscall(__NR_landlock, command, options, attr_ptr, attr_size, + NULL, 0); +} +#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, + sizeof(caps) / sizeof(caps[0]), + 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 can't 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); +} + +FIXTURE(ruleset_rw) { + struct landlock_attr_ruleset attr_ruleset; + int ruleset_fd; +}; + +FIXTURE_SETUP(ruleset_rw) { + self->attr_ruleset.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE; + self->ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, + &self->attr_ruleset, sizeof(self->attr_ruleset)); + ASSERT_LE(0, self->ruleset_fd); +} + +FIXTURE_TEARDOWN(ruleset_rw) { + ASSERT_EQ(0, close(self->ruleset_fd)); +} 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..1e94857ea152 --- /dev/null +++ b/tools/testing/selftests/landlock/fs_test.c @@ -0,0 +1,1730 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Landlock tests - Filesystem + * + * Copyright © 2017-2020 Mickaël Salaün mic@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(ruleset_rw, inval) +{ + struct landlock_attr_path_beneath path_beneath = { + .allowed_access = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE, + .parent_fd = -1, + }; + struct landlock_attr_enforce attr_enforce = {}; + + path_beneath.parent_fd = open(dir_s1d2, O_PATH | O_DIRECTORY | + O_CLOEXEC); + ASSERT_LE(0, path_beneath.parent_fd); + + path_beneath.ruleset_fd = open(dir_s1d1, O_PATH | O_DIRECTORY | + O_CLOEXEC); + ASSERT_LE(0, path_beneath.ruleset_fd); + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + /* Returns EBADF because ruleset_fd contains O_PATH. */ + ASSERT_EQ(EBADF, errno); + ASSERT_EQ(0, close(path_beneath.ruleset_fd)); + + path_beneath.ruleset_fd = open(dir_s1d1, O_DIRECTORY | O_CLOEXEC); + ASSERT_LE(0, path_beneath.ruleset_fd); + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + /* Returns EBADFD because ruleset_fd is not a valid ruleset. */ + ASSERT_EQ(EBADFD, errno); + ASSERT_EQ(0, close(path_beneath.ruleset_fd)); + + path_beneath.ruleset_fd = self->ruleset_fd; + ASSERT_EQ(0, landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + 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(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + 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(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + 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(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + ASSERT_EQ(EINVAL, errno); + path_beneath.allowed_access &= ~(1ULL << 60); + + /* Test with no access. */ + path_beneath.allowed_access = 0; + ASSERT_EQ(0, landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + 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)); + + attr_enforce.ruleset_fd = self->ruleset_fd; + ASSERT_EQ(0, landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, &attr_enforce, + sizeof(attr_enforce))); +} + +#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_CHROOT | \ + 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_attr_path_beneath path_beneath = {}; + struct landlock_attr_ruleset attr_ruleset = { + .handled_access_fs = ACCESS_ALL, + }; + + path_beneath.ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + ASSERT_LE(0, path_beneath.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(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath)); + 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_attr_path_beneath path_beneath = { + .ruleset_fd = ruleset_fd, + .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(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))) { + 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_attr_features attr_features = {}; + struct landlock_attr_ruleset attr_ruleset = { + .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"); + } + + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, &attr_features, + sizeof(attr_features))); + /* Only for test, use a binary AND for real application instead. */ + ASSERT_EQ(attr_ruleset.handled_access_fs, + attr_ruleset.handled_access_fs & + attr_features.access_fs); + ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + ASSERT_LE(0, ruleset_fd) { + TH_LOG("Failed to create a ruleset: %s", strerror(errno)); + } + + for (i = 0; rules[i].path; i++) { + ASSERT_EQ(rules[i].access, rules[i].access & + attr_features.access_fs); + 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) +{ + struct landlock_attr_enforce attr_enforce = { + .ruleset_fd = ruleset_fd, + }; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); + ASSERT_EQ(0, landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, &attr_enforce, + sizeof(attr_enforce))) { + 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_attr_path_beneath path_beneath; + const int ruleset_fd = create_ruleset(_metadata, rules[0].access | + LANDLOCK_ACCESS_FS_READ_DIR, rules); + + 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.ruleset_fd = ruleset_fd; + 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(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + 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, + }, + {} + }; + struct landlock_attr_enforce attr_enforce = {}; + + drop_privileges(_metadata); + attr_enforce.ruleset_fd = create_ruleset(_metadata, ACCESS_RO, rules); + ASSERT_LE(0, attr_enforce.ruleset_fd); + ASSERT_EQ(-1, landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, &attr_enforce, + sizeof(attr_enforce))); + ASSERT_EQ(EPERM, errno); + + /* enforce_ruleset() calls prctl(no_new_privs). */ + enforce_ruleset(_metadata, attr_enforce.ruleset_fd); + EXPECT_EQ(0, close(attr_enforce.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, + }, + {} + }; + const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules); + + set_cap(_metadata, CAP_SYS_CHROOT); + + 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_CHROOT, + * chroot(2) should be allowed. + */ + ASSERT_EQ(0, chroot(dir_s1d1)); + ASSERT_EQ(0, chroot(dir_s1d2)); + ASSERT_EQ(0, chroot(dir_s1d3)); +} + +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); + struct landlock_attr_enforce attr_enforce = { + .ruleset_fd = ruleset_fd, + }; + + ASSERT_LE(0, ruleset_fd); + for (i = 0; i < 64; i++) + enforce_ruleset(_metadata, ruleset_fd); + + for (i = 0; i < 2; i++) { + err = landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, &attr_enforce, + sizeof(attr_enforce)); + ASSERT_EQ(-1, err); + ASSERT_EQ(E2BIG, errno); + } + EXPECT_EQ(0, close(ruleset_fd)); +} + +TEST_F(layout1, empty_or_same_ruleset) +{ + struct landlock_attr_enforce attr_enforce = {}; + struct landlock_attr_ruleset attr_ruleset = {}; + + /* Tests empty handled_access_fs. */ + attr_enforce.ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + ASSERT_LE(-1, attr_enforce.ruleset_fd); + ASSERT_EQ(ENOMSG, errno); + + /* Enforces policy which deny read access to all files. */ + attr_ruleset.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE; + attr_enforce.ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + ASSERT_LE(0, attr_enforce.ruleset_fd); + enforce_ruleset(_metadata, attr_enforce.ruleset_fd); + test_path(_metadata, file1_s1d1, -1); + test_path(_metadata, dir_s1d1, 0); + + /* Nests a policy which deny read access to all directories. */ + attr_ruleset.handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR; + attr_enforce.ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + ASSERT_LE(0, attr_enforce.ruleset_fd); + enforce_ruleset(_metadata, attr_enforce.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, attr_enforce.ruleset_fd); + EXPECT_EQ(0, close(attr_enforce.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); +} + +TEST_F(layout1, chroot) +{ + const struct rule rules[] = { + { + .path = dir_s1d2, + .access = LANDLOCK_ACCESS_FS_CHROOT, + }, + {} + }; + const int ruleset_fd = create_ruleset(_metadata, rules[0].access, + rules); + + ASSERT_LE(0, ruleset_fd); + + set_cap(_metadata, CAP_SYS_CHROOT); + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, chroot(dir_s1d1)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, chroot(dir_s1d2)) { + TH_LOG("Failed to chroot into "%s": %s", file1_s1d2, + strerror(errno)); + }; + /* This chroot still works because we didn't chdir(dir_s1d2). */ + ASSERT_EQ(0, chroot(dir_s1d3)); +} + +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, + major(1) | minor(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, + major(7) | minor(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) +{ + 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_LE(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..03a3258cf78e --- /dev/null +++ b/tools/testing/selftests/landlock/ptrace_test.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Landlock tests - Ptrace + * + * 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 <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_attr_features attr_features; + struct landlock_attr_enforce attr_enforce; + struct landlock_attr_ruleset attr_ruleset = { + .handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE, + }; + struct landlock_attr_path_beneath path_beneath = { + .allowed_access = LANDLOCK_ACCESS_FS_READ_FILE, + }; + + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, + &attr_features, sizeof(attr_features))); + /* Only for test, use a binary AND for real application instead. */ + ASSERT_EQ(attr_ruleset.handled_access_fs, + attr_ruleset.handled_access_fs & + attr_features.access_fs); + ruleset_fd = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, &attr_ruleset, + sizeof(attr_ruleset)); + ASSERT_LE(0, ruleset_fd) { + TH_LOG("Failed to create a ruleset: %s", strerror(errno)); + } + path_beneath.ruleset_fd = ruleset_fd; + path_beneath.parent_fd = open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY + | O_CLOEXEC); + ASSERT_LE(0, path_beneath.parent_fd); + ASSERT_EQ(0, landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + &path_beneath, sizeof(path_beneath))); + ASSERT_EQ(0, errno); + ASSERT_EQ(0, close(path_beneath.parent_fd)); + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); + ASSERT_EQ(0, errno); + + attr_enforce.ruleset_fd = ruleset_fd; + ASSERT_EQ(0, landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, &attr_enforce, + sizeof(attr_enforce))); + ASSERT_EQ(0, errno); + + ASSERT_EQ(0, close(ruleset_fd)); +} + +/* test PTRACE_TRACEME and PTRACE_ATTACH for parent and child */ +static void check_ptrace(struct __test_metadata *const _metadata, + const bool domain_both, const bool domain_parent, + const bool domain_child) +{ + 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 (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 (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(domain_child ? -1 : 0, + ptrace(PTRACE_ATTACH, parent, NULL, 0)); + if (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(domain_parent ? -1 : 0, ptrace(PTRACE_TRACEME)); + if (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 (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 (!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(domain_parent ? -1 : 0, + ptrace(PTRACE_ATTACH, child, NULL, 0)); + if (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 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 + */ +TEST(allow_without_domain) { + check_ptrace(_metadata, false, false, false); +} + +/* + * Child domain + * + * P1--. P1 -> P2 : allow + * \ P2 -> P1 : deny + * .'-----. + * | P2 | + * '------' + */ +TEST(allow_with_one_domain) { + check_ptrace(_metadata, false, false, true); +} + +/* + * Parent domain + * .------. + * | P1 --. P1 -> P2 : deny + * '------' \ P2 -> P1 : allow + * ' + * P2 + */ +TEST(deny_with_parent_domain) { + check_ptrace(_metadata, false, true, false); +} + +/* + * Parent + child domain (siblings) + * .------. + * | P1 ---. P1 -> P2 : deny + * '------' \ P2 -> P1 : deny + * .---'--. + * | P2 | + * '------' + */ +TEST(deny_with_sibling_domain) { + check_ptrace(_metadata, false, true, true); +} + +/* + * Same domain (inherited) + * .-------------. + * | P1----. | P1 -> P2 : allow + * | \ | P2 -> P1 : allow + * | ' | + * | P2 | + * '-------------' + */ +TEST(allow_sibling_domain) { + check_ptrace(_metadata, true, false, false); +} + +/* + * Inherited + child domain + * .-----------------. + * | P1----. | P1 -> P2 : allow + * | \ | P2 -> P1 : deny + * | .-'----. | + * | | P2 | | + * | '------' | + * '-----------------' + */ +TEST(allow_with_nested_domain) { + check_ptrace(_metadata, true, false, true); +} + +/* + * Inherited + parent domain + * .-----------------. + * |.------. | P1 -> P2 : deny + * || P1 ----. | P2 -> P1 : allow + * |'------' \ | + * | ' | + * | P2 | + * '-----------------' + */ +TEST(deny_with_nested_and_parent_domain) { + check_ptrace(_metadata, true, true, false); +} + +/* + * Inherited + parent and child domain (siblings) + * .-----------------. + * | .------. | P1 -> P2 : deny + * | | P1 . | P2 -> P1 : deny + * | '------'\ | + * | \ | + * | .--'---. | + * | | P2 | | + * | '------' | + * '-----------------' + */ +TEST(deny_with_forked_domain) { + check_ptrace(_metadata, true, true, true); +} + +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; +}