Test landlock syscall, ptrace hooks semantic and filesystem access-control.
Signed-off-by: Mickaël Salaün mic@digikod.net Reviewed-by: Vincent Dagonneau vincent.dagonneau@ssi.gouv.fr Cc: Andy Lutomirski luto@amacapital.net Cc: James Morris jmorris@namei.org Cc: Kees Cook keescook@chromium.org Cc: Serge E. Hallyn serge@hallyn.com Cc: Shuah Khan shuah@kernel.org ---
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 version: https://lore.kernel.org/lkml/20191104172146.30797-7-mic@digikod.net/ --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/landlock/.gitignore | 4 + tools/testing/selftests/landlock/Makefile | 26 + tools/testing/selftests/landlock/common.h | 42 + tools/testing/selftests/landlock/config | 5 + tools/testing/selftests/landlock/test_base.c | 113 ++ tools/testing/selftests/landlock/test_fs.c | 1249 +++++++++++++++++ .../testing/selftests/landlock/test_ptrace.c | 294 ++++ tools/testing/selftests/landlock/true.c | 5 + 9 files changed, 1739 insertions(+) create mode 100644 tools/testing/selftests/landlock/.gitignore create mode 100644 tools/testing/selftests/landlock/Makefile create mode 100644 tools/testing/selftests/landlock/common.h create mode 100644 tools/testing/selftests/landlock/config create mode 100644 tools/testing/selftests/landlock/test_base.c create mode 100644 tools/testing/selftests/landlock/test_fs.c create mode 100644 tools/testing/selftests/landlock/test_ptrace.c create mode 100644 tools/testing/selftests/landlock/true.c
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 6ec503912bea..5183f269c244 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..fd081d6ef7c0 --- /dev/null +++ b/tools/testing/selftests/landlock/.gitignore @@ -0,0 +1,4 @@ +/test_base +/test_fs +/test_ptrace +/true diff --git a/tools/testing/selftests/landlock/Makefile b/tools/testing/selftests/landlock/Makefile new file mode 100644 index 000000000000..96ec5863c156 --- /dev/null +++ b/tools/testing/selftests/landlock/Makefile @@ -0,0 +1,26 @@ +# SPDX-License-Identifier: GPL-2.0 + +test_src := $(wildcard test_*.c) + +TEST_GEN_PROGS := $(test_src:.c=) + +TEST_GEN_PROGS_EXTENDED := true + +KSFT_KHDR_INSTALL := 1 +include ../lib.mk + +# Cf. tools/testing/selftests/arm64/Makefile +ifeq ($(KBUILD_OUTPUT),) +khdr_dir = $(top_srcdir)/usr/include +else +khdr_dir = $(KBUILD_OUTPUT)/kselftest/usr/include +endif + +CFLAGS += -Wall -O2 -I$(khdr_dir) + +$(khdr_dir)/linux/landlock.h: khdr + +$(TEST_GEN_PROGS): $(khdr_dir)/linux/landlock.h ../kselftest_harness.h common.h + +$(OUTPUT)/true: true.c + $(CC) -Os -static -o $@ $< diff --git a/tools/testing/selftests/landlock/common.h b/tools/testing/selftests/landlock/common.h new file mode 100644 index 000000000000..3e0d56a4363a --- /dev/null +++ b/tools/testing/selftests/landlock/common.h @@ -0,0 +1,42 @@ +/* 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/syscall.h> + +#include "../kselftest_harness.h" + +#ifndef landlock +static inline int landlock(const unsigned int command, + const unsigned int options, + const size_t attr_size, void *const attr_ptr) +{ + errno = 0; + return syscall(__NR_landlock, command, options, attr_size, attr_ptr, 0, + NULL); +} +#endif + +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, + sizeof(self->attr_ruleset), &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/test_base.c b/tools/testing/selftests/landlock/test_base.c new file mode 100644 index 000000000000..effc419593ce --- /dev/null +++ b/tools/testing/selftests/landlock/test_base.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Landlock tests - common resources + * + * 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 <sys/prctl.h> + +#include "common.h" + +#define FDINFO_TEMPLATE "/proc/self/fdinfo/%d" +#define FDINFO_SIZE 128 + +#ifndef O_PATH +#define O_PATH 010000000 +#endif + +TEST_F(ruleset_rw, fdinfo) +{ + int fdinfo_fd, fdinfo_path_size, fdinfo_buf_size; + char fdinfo_path[sizeof(FDINFO_TEMPLATE) + 2]; + char fdinfo_buf[FDINFO_SIZE]; + + fdinfo_path_size = snprintf(fdinfo_path, sizeof(fdinfo_path), + FDINFO_TEMPLATE, self->ruleset_fd); + ASSERT_LE(fdinfo_path_size, sizeof(fdinfo_path)); + + fdinfo_fd = open(fdinfo_path, O_RDONLY | O_CLOEXEC); + ASSERT_GE(fdinfo_fd, 0); + + fdinfo_buf_size = read(fdinfo_fd, fdinfo_buf, sizeof(fdinfo_buf)); + ASSERT_LE(fdinfo_buf_size, sizeof(fdinfo_buf) - 1); + + /* + * fdinfo_buf: pos: 0 + * flags: 02000002 + * mnt_id: 13 + * handled_access_fs: 804000 + */ + EXPECT_EQ(0, close(fdinfo_fd)); +} + +TEST(features) +{ + struct landlock_attr_features attr_features = { + .options_get_features = ~0ULL, + .options_create_ruleset = ~0ULL, + .options_add_rule = ~0ULL, + .options_enforce_ruleset = ~0ULL, + .access_fs = ~0ULL, + .size_attr_ruleset = ~0ULL, + .size_attr_path_beneath = ~0ULL, + .size_attr_enforce = ~0ULL, + }; + + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, + sizeof(attr_features), &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(((LANDLOCK_ACCESS_FS_CHROOT << 1) - 1), + attr_features.access_fs); + 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); +} + +TEST(empty_attr_ruleset) { + int err; + + /* Similar to struct landlock_attr_create.handled_access_fs = 0 */ + err = landlock(LANDLOCK_CMD_CREATE_RULESET, + LANDLOCK_OPT_CREATE_RULESET, 0, NULL); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(err, -1); +} + +TEST(empty_attr_path_beneath) { + int err; + + /* Similar to struct landlock_attr_path_beneath.*_fd = 0 */ + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, 0, NULL); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(err, -1); +} + +TEST(empty_attr_enforce) { + int err; + + /* Similar to struct landlock_attr_enforce.ruleset_fd = 0 */ + err = landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, 0, NULL); + ASSERT_EQ(errno, EINVAL); + ASSERT_EQ(err, -1); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/landlock/test_fs.c b/tools/testing/selftests/landlock/test_fs.c new file mode 100644 index 000000000000..747f2cf7a59f --- /dev/null +++ b/tools/testing/selftests/landlock/test_fs.c @@ -0,0 +1,1249 @@ +// 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/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_NAME "file" +#define BINARY_PATH "./true" + +/* Paths (sibling number and depth) */ +static const char dir_s1d1[] = TMP_DIR "s1d1"; +static const char file_s1d1[] = TMP_DIR "s1d1/" FILE_NAME; +static const char dir_s1d2[] = TMP_DIR "s1d1/s1d2"; +static const char file_s1d2[] = TMP_DIR "s1d1/s1d2/" FILE_NAME; +static const char dir_s1d3[] = TMP_DIR "s1d1/s1d2/s1d3"; +static const char file_s1d3[] = TMP_DIR "s1d1/s1d2/s1d3/" FILE_NAME; + +static const char dir_s2d1[] = TMP_DIR "s2d1"; +static const char file_s2d1[] = TMP_DIR "s2d1/" FILE_NAME; +static const char dir_s2d2[] = TMP_DIR "s2d1/s2d2"; +static const char file_s2d2[] = TMP_DIR "s2d1/s2d2/" FILE_NAME; +static const char dir_s2d3[] = TMP_DIR "s2d1/s2d2/s2d3"; +static const char file_s2d3[] = TMP_DIR "s2d1/s2d2/s2d3/" FILE_NAME; + +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; + const size_t file_name_len = sizeof(FILE_NAME); + char *const file_path = alloca(strlen(dir_path) + file_name_len + 2); + + strcpy(file_path, dir_path); + strcat(file_path, "/"); + strcat(file_path, FILE_NAME); + + ASSERT_EQ(0, mkdir(dir_path, 0700)) { + TH_LOG("Failed to create directory "%s": %s\n", dir_path, + strerror(errno)); + } + file_fd = open(file_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 file_path = alloca(strlen(dir_path) + + sizeof(FILE_NAME) + 2); + + strcpy(file_path, dir_path); + strcat(file_path, "/"); + strcat(file_path, FILE_NAME); + + unlink(file_path); + /* file_path may be a directory, cf. layout1/make_directory. */ + rmdir(file_path); + rmdir(dir_path); +} + +static void cleanup_layout1(void) +{ + 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); + umount(dir_s3d2); + delete_dir_and_file(dir_s3d2); + delete_dir_and_file(dir_s3d1); + + delete_dir_and_file(TMP_DIR); +} + +FIXTURE(layout1) { +}; + +FIXTURE_SETUP(layout1) +{ + cleanup_layout1(); + + /* Do not pollute the rest of the system. */ + ASSERT_NE(-1, unshare(CLONE_NEWNS)); + 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); + ASSERT_EQ(0, mount("tmp", dir_s3d2, "tmpfs", 0, "size=4m,mode=700")); + 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\n", path, + strerror(errno)); + } + ASSERT_EQ(EACCES, errno) { + TH_LOG("Wrong error code to open "%s": %s\n", path, + strerror(errno)); + } + } else { + ASSERT_NE(-1, fd) { + TH_LOG("Failed to open "%s": %s\n", 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, file_s1d1, 0); + test_path(_metadata, dir_s1d2, 0); + test_path(_metadata, file_s1d2, 0); + test_path(_metadata, dir_s1d3, 0); + test_path(_metadata, file_s1d3, 0); + + test_path(_metadata, dir_s2d1, 0); + test_path(_metadata, file_s2d1, 0); + test_path(_metadata, dir_s2d2, 0); + test_path(_metadata, file_s2d2, 0); + test_path(_metadata, dir_s2d3, 0); + test_path(_metadata, file_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) +{ + int err; + 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.ruleset_fd = self->ruleset_fd; + path_beneath.parent_fd = open(dir_s1d2, O_PATH | O_DIRECTORY | + O_CLOEXEC); + ASSERT_GE(path_beneath.parent_fd, 0); + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + ASSERT_EQ(errno, 0); + ASSERT_EQ(err, 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_GE(path_beneath.parent_fd, 0); + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + ASSERT_EQ(err, -1); + ASSERT_EQ(errno, EBADR); + errno = 0; + 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_GE(path_beneath.parent_fd, 0); + + /* Test with legitimate values. */ + path_beneath.allowed_access |= LANDLOCK_ACCESS_FS_EXECUTE; + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + path_beneath.allowed_access &= ~LANDLOCK_ACCESS_FS_EXECUTE; + ASSERT_EQ(errno, EINVAL); + errno = 0; + ASSERT_EQ(err, -1); + + /* Test with unknown (64-bits) value. */ + path_beneath.allowed_access |= (1ULL << 60); + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + path_beneath.allowed_access &= ~(1ULL << 60); + ASSERT_EQ(errno, EINVAL); + errno = 0; + ASSERT_EQ(err, -1); + + /* Test with no access. */ + path_beneath.allowed_access = 0; + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + path_beneath.allowed_access &= ~(1ULL << 60); + ASSERT_EQ(err, 0); + + ASSERT_EQ(0, close(path_beneath.parent_fd)); + + err = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(errno, 0); + ASSERT_EQ(err, 0); + + attr_enforce.ruleset_fd = self->ruleset_fd; + err = landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, sizeof(attr_enforce), + &attr_enforce); + ASSERT_EQ(errno, 0); + ASSERT_EQ(err, 0); +} + +TEST_F(ruleset_rw, nsfs) +{ + struct landlock_attr_path_beneath path_beneath = { + .allowed_access = LANDLOCK_ACCESS_FS_READ_FILE | + LANDLOCK_ACCESS_FS_WRITE_FILE, + .ruleset_fd = self->ruleset_fd, + }; + int err; + + path_beneath.parent_fd = open("/proc/self/ns/mnt", O_PATH | O_CLOEXEC); + ASSERT_GE(path_beneath.parent_fd, 0); + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + ASSERT_EQ(errno, 0); + ASSERT_EQ(err, 0); + 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) +{ + int err; + 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_GE(path_beneath.parent_fd, 0) { + TH_LOG("Failed to open directory "%s": %s\n", path, + strerror(errno)); + } + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + ASSERT_EQ(err, 0) { + TH_LOG("Failed to update the ruleset with "%s": %s\n", path, + strerror(errno)); + } + ASSERT_EQ(errno, 0); + 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\n"); + } + ASSERT_NE(NULL, rules[0].path) { + TH_LOG("Empty rule list\n"); + } + + ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES, + LANDLOCK_OPT_GET_FEATURES, + sizeof(attr_features), &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, sizeof(attr_ruleset), + &attr_ruleset); + ASSERT_GE(ruleset_fd, 0) { + TH_LOG("Failed to create a ruleset: %s\n", 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, + }; + int err; + + err = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(errno, 0); + ASSERT_EQ(err, 0); + + err = landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, sizeof(attr_enforce), + &attr_enforce); + ASSERT_EQ(err, 0) { + TH_LOG("Failed to enforce ruleset: %s\n", strerror(errno)); + } + ASSERT_EQ(errno, 0); +} + +TEST_F(layout1, whitelist) +{ + const struct rule rules[] = { + { + .path = dir_s1d2, + .access = ACCESS_RO, + }, + { + .path = file_s2d2, + .access = ACCESS_RO, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules); + + ASSERT_NE(-1, 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, file_s1d1, -1); + test_path(_metadata, dir_s1d2, 0); + test_path(_metadata, file_s1d2, 0); + test_path(_metadata, dir_s1d3, 0); + test_path(_metadata, file_s1d3, 0); + + /* Tests on a file. */ + test_path(_metadata, dir_s2d2, -1); + test_path(_metadata, file_s2d2, 0); +} + +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); + + ASSERT_NE(-1, 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_NE(-1, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, open(file_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(file_s1d2, O_WRONLY | O_CLOEXEC); + ASSERT_NE(-1, open_fd); + EXPECT_EQ(0, close(open_fd)); + open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC); + ASSERT_NE(-1, open_fd); + EXPECT_EQ(0, close(open_fd)); + + open_fd = open(file_s1d3, O_WRONLY | O_CLOEXEC); + ASSERT_NE(-1, open_fd); + EXPECT_EQ(0, close(open_fd)); + open_fd = open(dir_s1d3, O_RDONLY | O_DIRECTORY | O_CLOEXEC); + ASSERT_NE(-1, open_fd); + EXPECT_EQ(0, close(open_fd)); +} + +TEST_F(layout1, inherit_superset) +{ + 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_NE(-1, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + + ASSERT_EQ(-1, open(file_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(file_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_NE(-1, open_fd); + ASSERT_EQ(0, close(open_fd)); + + /* Write access is forbidden. */ + ASSERT_EQ(-1, open(file_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_NE(-1, 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(file_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 file_s1d2. */ + ASSERT_EQ(-1, open(file_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_NE(-1, open_fd); + ASSERT_EQ(0, close(open_fd)); + + /* It is still forbidden to write in file_s1d3. */ + ASSERT_EQ(-1, open(file_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_NE(-1, 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(file_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 file_s1d2. */ + ASSERT_EQ(-1, open(file_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_NE(-1, open_fd); + ASSERT_EQ(0, close(open_fd)); + + /* It is still forbidden to write in file_s1d3. */ + ASSERT_EQ(-1, open(file_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_NE(-1, 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(file_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 file_s1d2. */ + ASSERT_EQ(-1, open(file_s1d2, O_WRONLY | O_CLOEXEC)); + /* Readdir access is still allowed. */ + open_fd = open(dir_s1d2, O_RDONLY | O_DIRECTORY | O_CLOEXEC); + ASSERT_NE(-1, open_fd); + ASSERT_EQ(0, close(open_fd)); + + /* It is still forbidden to write in file_s1d3. */ + ASSERT_EQ(-1, open(file_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, 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_NE(-1, 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_NE(-1, 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_NE(-1, 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; + + ASSERT_NE(-1, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL)); + ASSERT_NE(-1, syscall(SYS_pivot_root, dir_s3d2, dir_s3d3)) { + TH_LOG("Failed to pivot_root into "%s": %s\n", dir_s3d2, + strerror(errno)); + }; + ASSERT_NE(-1, chdir("/")); + + ruleset_fd = create_ruleset(_metadata, ACCESS_RW, rules); + ASSERT_NE(-1, 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_NE(-1, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL)); + ASSERT_EQ(-1, syscall(SYS_pivot_root, dir_s3d2, dir_s3d3)); +} + +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_NE(-1, 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; + } + enforce_ruleset(_metadata, ruleset_fd); + + switch (rel) { + case REL_OPEN: + dirfd = open(dir_s1d2, O_DIRECTORY); + ASSERT_NE(-1, dirfd); + break; + case REL_CHDIR: + ASSERT_NE(-1, chdir(dir_s1d2)); + dirfd = AT_FDCWD; + break; + case REL_CHROOT_ONLY: + /* Do chroot into dir_s1d2 (relative to dir_s2d2). */ + ASSERT_NE(-1, chroot("../../s1d1/s1d2")) { + TH_LOG("Failed to chroot: %s\n", strerror(errno)); + } + dirfd = AT_FDCWD; + break; + case REL_CHROOT_CHDIR: + /* Do chroot into dir_s1d2. */ + ASSERT_NE(-1, chroot(".")) { + TH_LOG("Failed to chroot: %s\n", 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, + LANDLOCK_ACCESS_FS_CHROOT, rules); + + ASSERT_NE(-1, ruleset_fd); + + 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\n", file_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\n", 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\n", + strerror(errno)); + } + ASSERT_EQ(0, fstat(src_fd, &statbuf)); + ASSERT_LE(0, 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\n", path, + strerror(errno)); + }; + ASSERT_EQ(EACCES, errno); + _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); + return; + } + ASSERT_EQ(child, waitpid(child, &status, 0)); + ASSERT_EQ(1, WIFEXITED(status)); + ASSERT_EQ(0, WEXITSTATUS(status)) { + TH_LOG("Unexpected return code for "%s": %s\n", path, + strerror(errno)); + }; +} + +TEST_F(layout1, execute) +{ + const struct rule rules[] = { + { + .path = dir_s1d1, + .access = LANDLOCK_ACCESS_FS_EXECUTE, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, + LANDLOCK_ACCESS_FS_EXECUTE, rules); + + ASSERT_NE(-1, ruleset_fd); + copy_binary(_metadata, file_s1d1); + copy_binary(_metadata, file_s1d2); + copy_binary(_metadata, file_s1d3); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + test_execute(_metadata, file_s1d1, -1); + test_execute(_metadata, file_s1d2, 0); + test_execute(_metadata, file_s1d3, 0); +} + +TEST_F(layout1, link_to) +{ + const struct rule rules[] = { + { + .path = dir_s1d2, + .access = LANDLOCK_ACCESS_FS_LINK_TO, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, + LANDLOCK_ACCESS_FS_LINK_TO, rules); + + ASSERT_NE(-1, ruleset_fd); + + ASSERT_EQ(0, unlink(file_s1d1)); + ASSERT_EQ(0, unlink(file_s1d2)); + ASSERT_EQ(0, unlink(file_s1d3)); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, link(file_s2d1, file_s1d1)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, link(file_s2d1, file_s1d2)) { + TH_LOG("Failed to link file to "%s": %s\n", file_s1d2, + strerror(errno)); + }; + ASSERT_EQ(0, link(file_s2d1, file_s1d3)); +} + +static void test_rename(struct __test_metadata *const _metadata) +{ + /* Renames files. */ + ASSERT_EQ(-1, rename(file_s2d1, file_s1d1)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, rename(file_s2d2, file_s1d2)) { + TH_LOG("Failed to rename file "%s": %s\n", file_s2d3, + strerror(errno)); + }; + ASSERT_EQ(0, rename(file_s2d3, file_s1d3)); + + /* Renames directories (reverse order). */ + ASSERT_EQ(0, unlink(file_s1d3)); + ASSERT_EQ(0, rename(dir_s2d3, dir_s1d3)) { + TH_LOG("Failed to rename directory "%s": %s\n", dir_s2d3, + strerror(errno)); + }; + + ASSERT_EQ(0, rmdir(dir_s1d3)); + ASSERT_EQ(0, unlink(file_s1d2)); + ASSERT_EQ(-1, rename(dir_s2d2, dir_s1d2)); + ASSERT_EQ(EACCES, errno); + + ASSERT_EQ(0, rmdir(dir_s1d2)); + ASSERT_EQ(0, unlink(file_s1d1)); + ASSERT_EQ(-1, rename(dir_s2d1, dir_s1d1)); + ASSERT_EQ(EACCES, errno); +} + +TEST_F(layout1, rename_from) +{ + const struct rule rules[] = { + { + .path = dir_s2d2, + .access = LANDLOCK_ACCESS_FS_RENAME_FROM, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, + LANDLOCK_ACCESS_FS_RENAME_FROM, rules); + + ASSERT_NE(-1, ruleset_fd); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + test_rename(_metadata); +} + +TEST_F(layout1, rename_to) +{ + /* + * Same tests as layout1/rename_from, except the rename_from access + * rule is on dir_s1d2. + */ + const struct rule rules[] = { + { + .path = dir_s1d2, + .access = LANDLOCK_ACCESS_FS_RENAME_TO, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, + LANDLOCK_ACCESS_FS_RENAME_TO, rules); + + ASSERT_NE(-1, ruleset_fd); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + test_rename(_metadata); +} + +TEST_F(layout1, rmdir) +{ + const struct rule rules[] = { + { + .path = dir_s1d2, + .access = LANDLOCK_ACCESS_FS_RMDIR, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, + LANDLOCK_ACCESS_FS_RMDIR, rules); + + ASSERT_NE(-1, ruleset_fd); + + ASSERT_EQ(0, unlink(file_s1d1)); + ASSERT_EQ(0, unlink(file_s1d2)); + ASSERT_EQ(0, unlink(file_s1d3)); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(0, rmdir(dir_s1d3)) { + TH_LOG("Failed to remove directory "%s": %s\n", file_s1d2, + strerror(errno)); + } + 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_UNLINK, + }, + {}, + }; + const int ruleset_fd = create_ruleset(_metadata, + LANDLOCK_ACCESS_FS_UNLINK, rules); + + ASSERT_NE(-1, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, unlink(file_s1d1)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, unlink(file_s1d2)) { + TH_LOG("Failed to unlink file "%s": %s\n", file_s1d2, + strerror(errno)); + }; + ASSERT_EQ(0, unlink(file_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_NE(-1, ruleset_fd); + + ASSERT_EQ(0, unlink(file_s1d1)); + ASSERT_EQ(0, unlink(file_s1d2)); + ASSERT_EQ(0, unlink(file_s1d3)); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, mknod(file_s1d1, mode | 0400, dev)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, mknod(file_s1d2, mode | 0400, dev)) { + TH_LOG("Failed to make file "%s": %s\n", + file_s1d2, strerror(errno)); + }; + ASSERT_EQ(0, mknod(file_s1d3, mode | 0400, dev)); +} + +TEST_F(layout1, make_char) +{ + /* Creates a /dev/null device. */ + 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. */ + 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_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, + LANDLOCK_ACCESS_FS_MAKE_SYM, rules); + + ASSERT_NE(-1, ruleset_fd); + + ASSERT_EQ(0, unlink(file_s1d1)); + ASSERT_EQ(0, unlink(file_s1d2)); + ASSERT_EQ(0, unlink(file_s1d3)); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + ASSERT_EQ(-1, symlink("none", file_s1d1)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, symlink("none", file_s1d2)) { + TH_LOG("Failed to make symlink "%s": %s\n", + file_s1d2, strerror(errno)); + }; + ASSERT_EQ(0, symlink("none", file_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, + LANDLOCK_ACCESS_FS_MAKE_DIR, rules); + + ASSERT_NE(-1, ruleset_fd); + + ASSERT_EQ(0, unlink(file_s1d1)); + ASSERT_EQ(0, unlink(file_s1d2)); + ASSERT_EQ(0, unlink(file_s1d3)); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + + /* Uses file_* as directory names. */ + ASSERT_EQ(-1, mkdir(file_s1d1, 0700)); + ASSERT_EQ(EACCES, errno); + ASSERT_EQ(0, mkdir(file_s1d2, 0700)) { + TH_LOG("Failed to make directory "%s": %s\n", + file_s1d2, strerror(errno)); + }; + ASSERT_EQ(0, mkdir(file_s1d3, 0700)); +} + +TEST(cleanup) +{ + cleanup_layout1(); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/landlock/test_ptrace.c b/tools/testing/selftests/landlock/test_ptrace.c new file mode 100644 index 000000000000..407cc99e5340 --- /dev/null +++ b/tools/testing/selftests/landlock/test_ptrace.c @@ -0,0 +1,294 @@ +// 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, err; + 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, + sizeof(attr_features), &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, sizeof(attr_ruleset), + &attr_ruleset); + ASSERT_GE(ruleset_fd, 0) { + TH_LOG("Failed to create a ruleset: %s\n", strerror(errno)); + } + path_beneath.ruleset_fd = ruleset_fd; + path_beneath.parent_fd = open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY + | O_CLOEXEC); + ASSERT_GE(path_beneath.parent_fd, 0); + err = landlock(LANDLOCK_CMD_ADD_RULE, + LANDLOCK_OPT_ADD_RULE_PATH_BENEATH, + sizeof(path_beneath), &path_beneath); + ASSERT_EQ(err, 0); + ASSERT_EQ(errno, 0); + ASSERT_EQ(0, close(path_beneath.parent_fd)); + + err = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(errno, 0); + ASSERT_EQ(err, 0); + + attr_enforce.ruleset_fd = ruleset_fd; + err = landlock(LANDLOCK_CMD_ENFORCE_RULESET, + LANDLOCK_OPT_ENFORCE_RULESET, sizeof(attr_enforce), + &attr_enforce); + ASSERT_EQ(err, 0); + ASSERT_EQ(errno, 0); + + 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; + + 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; +}