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Subject[RFC PATCH v14 08/10] selftests/landlock: Add initial tests
Date
Test landlock syscall, ptrace hooks semantic and filesystem
access-control.

This is an initial batch, more tests will follow.

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 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 | 3 +
tools/testing/selftests/landlock/Makefile | 13 +
tools/testing/selftests/landlock/config | 4 +
tools/testing/selftests/landlock/test.h | 40 ++
tools/testing/selftests/landlock/test_base.c | 80 +++
tools/testing/selftests/landlock/test_fs.c | 624 ++++++++++++++++++
.../testing/selftests/landlock/test_ptrace.c | 293 ++++++++
8 files changed, 1058 insertions(+)
create mode 100644 tools/testing/selftests/landlock/.gitignore
create mode 100644 tools/testing/selftests/landlock/Makefile
create mode 100644 tools/testing/selftests/landlock/config
create mode 100644 tools/testing/selftests/landlock/test.h
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

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..4ee53c733af0
--- /dev/null
+++ b/tools/testing/selftests/landlock/.gitignore
@@ -0,0 +1,3 @@
+/test_base
+/test_fs
+/test_ptrace
diff --git a/tools/testing/selftests/landlock/Makefile b/tools/testing/selftests/landlock/Makefile
new file mode 100644
index 000000000000..c7e26e1251c4
--- /dev/null
+++ b/tools/testing/selftests/landlock/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+
+test_src := $(wildcard test_*.c)
+
+TEST_GEN_PROGS := $(test_src:.c=)
+
+usr_include := ../../../../usr/include
+
+CFLAGS += -Wall -O2 -I$(usr_include)
+
+include ../lib.mk
+
+$(TEST_GEN_PROGS): ../kselftest_harness.h $(usr_include)/linux/landlock.h
diff --git a/tools/testing/selftests/landlock/config b/tools/testing/selftests/landlock/config
new file mode 100644
index 000000000000..662f72c5a0df
--- /dev/null
+++ b/tools/testing/selftests/landlock/config
@@ -0,0 +1,4 @@
+CONFIG_HEADERS_INSTALL=y
+CONFIG_SECURITY_LANDLOCK=y
+CONFIG_SECURITY_PATH=y
+CONFIG_SECURITY=y
diff --git a/tools/testing/selftests/landlock/test.h b/tools/testing/selftests/landlock/test.h
new file mode 100644
index 000000000000..f9cebd8fc169
--- /dev/null
+++ b/tools/testing/selftests/landlock/test.h
@@ -0,0 +1,40 @@
+/* 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 <sys/syscall.h>
+
+#include "../kselftest_harness.h"
+
+#ifndef landlock
+static inline int landlock(unsigned int command, unsigned int options,
+ size_t attr_size, void *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 |
+ LANDLOCK_ACCESS_FS_WRITE;
+ 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/test_base.c b/tools/testing/selftests/landlock/test_base.c
new file mode 100644
index 000000000000..1ac7dbead3b2
--- /dev/null
+++ b/tools/testing/selftests/landlock/test_base.c
@@ -0,0 +1,80 @@
+// 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 "test.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,
+ };
+
+ ASSERT_EQ(0, landlock(LANDLOCK_CMD_GET_FEATURES,
+ LANDLOCK_OPT_CREATE_RULESET,
+ 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_MAP << 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);
+}
+
+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..627cb3a71f89
--- /dev/null
+++ b/tools/testing/selftests/landlock/test_fs.c
@@ -0,0 +1,624 @@
+// 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 <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "test.h"
+
+#define TMP_PREFIX "tmp_"
+
+/* Paths (sibling number and depth) */
+const char dir_s0_d1[] = TMP_PREFIX "a0";
+const char dir_s0_d2[] = TMP_PREFIX "a0/b0";
+const char dir_s0_d3[] = TMP_PREFIX "a0/b0/c0";
+const char dir_s1_d1[] = TMP_PREFIX "a1";
+const char dir_s2_d1[] = TMP_PREFIX "a2";
+const char dir_s2_d2[] = TMP_PREFIX "a2/b2";
+
+/* dir_s3_d1 is a tmpfs mount. */
+const char dir_s3_d1[] = TMP_PREFIX "a3";
+const char dir_s3_d2[] = TMP_PREFIX "a3/b3";
+
+/* dir_s4_d2 is a tmpfs mount. */
+const char dir_s4_d1[] = TMP_PREFIX "a4";
+const char dir_s4_d2[] = TMP_PREFIX "a4/b4";
+
+static void cleanup_layout1(void)
+{
+ rmdir(dir_s2_d2);
+ rmdir(dir_s2_d1);
+ rmdir(dir_s1_d1);
+ rmdir(dir_s0_d3);
+ rmdir(dir_s0_d2);
+ rmdir(dir_s0_d1);
+
+ /* dir_s3_d2 may be bind mounted */
+ umount(dir_s3_d2);
+ rmdir(dir_s3_d2);
+ umount(dir_s3_d1);
+ rmdir(dir_s3_d1);
+
+ umount(dir_s4_d2);
+ rmdir(dir_s4_d2);
+ rmdir(dir_s4_d1);
+}
+
+FIXTURE(layout1) {
+};
+
+FIXTURE_SETUP(layout1)
+{
+ cleanup_layout1();
+
+ /* Do not pollute the rest of the system. */
+ ASSERT_NE(-1, unshare(CLONE_NEWNS));
+
+ ASSERT_EQ(0, mkdir(dir_s0_d1, 0600));
+ ASSERT_EQ(0, mkdir(dir_s0_d2, 0600));
+ ASSERT_EQ(0, mkdir(dir_s0_d3, 0600));
+ ASSERT_EQ(0, mkdir(dir_s1_d1, 0600));
+ ASSERT_EQ(0, mkdir(dir_s2_d1, 0600));
+ ASSERT_EQ(0, mkdir(dir_s2_d2, 0600));
+
+ ASSERT_EQ(0, mkdir(dir_s3_d1, 0600));
+ ASSERT_EQ(0, mount("tmp", dir_s3_d1, "tmpfs", 0, NULL));
+ ASSERT_EQ(0, mkdir(dir_s3_d2, 0600));
+
+ ASSERT_EQ(0, mkdir(dir_s4_d1, 0600));
+ ASSERT_EQ(0, mkdir(dir_s4_d2, 0600));
+ ASSERT_EQ(0, mount("tmp", dir_s4_d2, "tmpfs", 0, NULL));
+}
+
+FIXTURE_TEARDOWN(layout1)
+{
+ /*
+ * cleanup_layout1() would be denied here, use TEST(cleanup) instead.
+ */
+}
+
+static void test_path_rel(struct __test_metadata *_metadata, int dirfd,
+ const char *path, int ret)
+{
+ int fd;
+ struct stat statbuf;
+
+ /* faccessat() can not be restricted for now */
+ ASSERT_EQ(ret, fstatat(dirfd, path, &statbuf, 0)) {
+ TH_LOG("fstatat path \"%s\" returned %s\n", path,
+ strerror(errno));
+ }
+ if (ret) {
+ ASSERT_EQ(EACCES, errno);
+ }
+ fd = openat(dirfd, path, O_DIRECTORY);
+ if (ret) {
+ ASSERT_EQ(-1, fd);
+ ASSERT_EQ(EACCES, errno);
+ } else {
+ ASSERT_NE(-1, fd);
+ EXPECT_EQ(0, close(fd));
+ }
+}
+
+static void test_path(struct __test_metadata *_metadata, const char *path,
+ int ret)
+{
+ return test_path_rel(_metadata, AT_FDCWD, path, ret);
+}
+
+TEST_F(layout1, no_restriction)
+{
+ test_path(_metadata, dir_s0_d1, 0);
+ test_path(_metadata, dir_s0_d2, 0);
+ test_path(_metadata, dir_s0_d3, 0);
+ test_path(_metadata, dir_s1_d1, 0);
+ test_path(_metadata, dir_s2_d2, 0);
+}
+
+TEST_F(ruleset_rw, inval)
+{
+ int err;
+ struct landlock_attr_path_beneath path_beneath = {
+ .allowed_access = LANDLOCK_ACCESS_FS_READ |
+ LANDLOCK_ACCESS_FS_WRITE,
+ .parent_fd = -1,
+ };
+ struct landlock_attr_enforce attr_enforce;
+
+ path_beneath.ruleset_fd = self->ruleset_fd;
+ path_beneath.parent_fd = open(dir_s0_d2, 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(errno, 0);
+ ASSERT_EQ(err, 0);
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+
+ /* Tests without O_PATH. */
+ path_beneath.parent_fd = open(dir_s0_d2, 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, -1);
+ ASSERT_EQ(errno, EBADR);
+ errno = 0;
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+
+ /* Checks un-handled access. */
+ path_beneath.parent_fd = open(dir_s0_d2, O_PATH | O_NOFOLLOW |
+ O_DIRECTORY | O_CLOEXEC);
+ ASSERT_GE(path_beneath.parent_fd, 0);
+ 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);
+ ASSERT_EQ(errno, EINVAL);
+ errno = 0;
+ ASSERT_EQ(err, -1);
+ 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 |
+ LANDLOCK_ACCESS_FS_WRITE,
+ .ruleset_fd = self->ruleset_fd,
+ };
+ int err;
+
+ path_beneath.parent_fd = open("/proc/self/ns/mnt", O_PATH | O_NOFOLLOW |
+ 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 *_metadata, int ruleset_fd,
+ __u64 allowed_access, const char *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_NOFOLLOW | O_DIRECTORY |
+ 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));
+}
+
+static int create_ruleset(struct __test_metadata *_metadata,
+ const char *const dirs[])
+{
+ int ruleset_fd, dirs_len, i;
+ struct landlock_attr_features attr_features;
+ struct landlock_attr_ruleset attr_ruleset = {
+ .handled_access_fs =
+ LANDLOCK_ACCESS_FS_OPEN |
+ LANDLOCK_ACCESS_FS_READ |
+ LANDLOCK_ACCESS_FS_WRITE |
+ LANDLOCK_ACCESS_FS_EXECUTE |
+ LANDLOCK_ACCESS_FS_GETATTR
+ };
+ __u64 allowed_access =
+ LANDLOCK_ACCESS_FS_OPEN |
+ LANDLOCK_ACCESS_FS_READ |
+ LANDLOCK_ACCESS_FS_GETATTR;
+
+ ASSERT_NE(NULL, dirs) {
+ TH_LOG("No directory list\n");
+ }
+ ASSERT_NE(NULL, dirs[0]) {
+ TH_LOG("Empty directory list\n");
+ }
+ /* Gets the number of dir entries. */
+ for (dirs_len = 0; dirs[dirs_len]; dirs_len++);
+
+ 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);
+ ASSERT_EQ(allowed_access, allowed_access & 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; dirs[i]; i++) {
+ add_path_beneath(_metadata, ruleset_fd, allowed_access,
+ dirs[i]);
+ }
+ return ruleset_fd;
+}
+
+static void enforce_ruleset(struct __test_metadata *_metadata, 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)
+{
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s0_d2, dir_s1_d1, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, "/", -1);
+ test_path(_metadata, dir_s0_d1, -1);
+ test_path(_metadata, dir_s0_d2, 0);
+ test_path(_metadata, dir_s0_d3, 0);
+}
+
+TEST_F(layout1, unhandled_access)
+{
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s0_d2, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /*
+ * Because the policy does not handled LANDLOCK_ACCESS_FS_CHROOT,
+ * chroot(2) should be allowed.
+ */
+ ASSERT_EQ(0, chroot(dir_s0_d1));
+ ASSERT_EQ(0, chroot(dir_s0_d2));
+ ASSERT_EQ(0, chroot(dir_s0_d3));
+}
+
+TEST_F(layout1, ruleset_overlap)
+{
+ struct stat statbuf;
+ int open_fd;
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s1_d1, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ /* These rules should be ORed among them. */
+ add_path_beneath(_metadata, ruleset_fd,
+ LANDLOCK_ACCESS_FS_GETATTR, dir_s0_d2);
+ add_path_beneath(_metadata, ruleset_fd,
+ LANDLOCK_ACCESS_FS_OPEN, dir_s0_d2);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d1, &statbuf, 0));
+ ASSERT_EQ(-1, openat(AT_FDCWD, dir_s0_d1, O_DIRECTORY));
+ ASSERT_EQ(0, fstatat(AT_FDCWD, dir_s0_d2, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d2, O_DIRECTORY);
+ ASSERT_LE(0, open_fd);
+ EXPECT_EQ(0, close(open_fd));
+ ASSERT_EQ(0, fstatat(AT_FDCWD, dir_s0_d3, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d3, O_DIRECTORY);
+ ASSERT_LE(0, open_fd);
+ EXPECT_EQ(0, close(open_fd));
+}
+
+TEST_F(layout1, inherit_superset)
+{
+ struct stat statbuf;
+ int ruleset_fd, open_fd;
+
+ ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s1_d1, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ add_path_beneath(_metadata, ruleset_fd,
+ LANDLOCK_ACCESS_FS_OPEN, dir_s0_d2);
+ enforce_ruleset(_metadata, ruleset_fd);
+
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d1, &statbuf, 0));
+ ASSERT_EQ(-1, openat(AT_FDCWD, dir_s0_d1, O_DIRECTORY));
+
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d2, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d2, O_DIRECTORY);
+ ASSERT_NE(-1, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d3, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d3, O_DIRECTORY);
+ ASSERT_NE(-1, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /*
+ * Test 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_GETATTR,
+ dir_s0_d2);
+ /*
+ * In ruleset_fd, dir_s0_d2 should now have the LANDLOCK_ACCESS_FS_OPEN
+ * and LANDLOCK_ACCESS_FS_GETATTR access rights (even if this directory
+ * is opened a second time). However, when enforcing this updated
+ * ruleset, the ruleset tied to the current process will still only
+ * have the dir_s0_d2 with LANDLOCK_ACCESS_FS_OPEN access,
+ * LANDLOCK_ACCESS_FS_GETATTR 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, fstatat(AT_FDCWD, dir_s0_d1, &statbuf, 0));
+ ASSERT_EQ(-1, openat(AT_FDCWD, dir_s0_d1, O_DIRECTORY));
+
+ /* It is still forbiden to fstat(dir_s0_d2). */
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d2, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d2, O_DIRECTORY);
+ ASSERT_NE(-1, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d3, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d3, O_DIRECTORY);
+ ASSERT_NE(-1, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /*
+ * Now, dir_s0_d3 get a new rule tied to it, only allowing
+ * LANDLOCK_ACCESS_FS_GETATTR. The kernel internal difference is that
+ * there was no rule tied to it before.
+ */
+ add_path_beneath(_metadata, ruleset_fd, LANDLOCK_ACCESS_FS_GETATTR,
+ dir_s0_d3);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ /*
+ * Same tests and results as above, except for open(dir_s0_d3) which is
+ * now denied because the new rule mask the rule previously inherited
+ * from dir_s0_d2.
+ */
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d1, &statbuf, 0));
+ ASSERT_EQ(-1, openat(AT_FDCWD, dir_s0_d1, O_DIRECTORY));
+
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d2, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d2, O_DIRECTORY);
+ ASSERT_NE(-1, open_fd);
+ ASSERT_EQ(0, close(open_fd));
+
+ /* It is still forbiden to fstat(dir_s0_d3). */
+ ASSERT_EQ(-1, fstatat(AT_FDCWD, dir_s0_d3, &statbuf, 0));
+ open_fd = openat(AT_FDCWD, dir_s0_d3, O_DIRECTORY);
+ /* open(dir_s0_d3) is now forbidden. */
+ ASSERT_EQ(-1, open_fd);
+ ASSERT_EQ(EACCES, errno);
+}
+
+TEST_F(layout1, extend_ruleset_with_denied_path)
+{
+ struct landlock_attr_path_beneath path_beneath = {
+ .allowed_access = LANDLOCK_ACCESS_FS_GETATTR,
+ };
+
+ path_beneath.ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s0_d2, NULL });
+ ASSERT_NE(-1, path_beneath.ruleset_fd);
+ enforce_ruleset(_metadata, path_beneath.ruleset_fd);
+
+ ASSERT_EQ(-1, open(dir_s0_d1, O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC));
+ ASSERT_EQ(EACCES, errno);
+
+ /*
+ * Tests that we can't create a rule for which we are not allowed to
+ * open its path.
+ */
+ path_beneath.parent_fd = open(dir_s0_d1, O_PATH | O_NOFOLLOW
+ | O_DIRECTORY | O_CLOEXEC);
+ ASSERT_GE(path_beneath.parent_fd, 0);
+ ASSERT_EQ(-1, landlock(LANDLOCK_CMD_ADD_RULE,
+ LANDLOCK_OPT_CREATE_RULESET,
+ sizeof(path_beneath), &path_beneath));
+ ASSERT_EQ(EACCES, errno);
+ ASSERT_EQ(0, close(path_beneath.parent_fd));
+ EXPECT_EQ(0, close(path_beneath.ruleset_fd));
+}
+
+TEST_F(layout1, rule_on_mountpoint)
+{
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s0_d1, dir_s3_d1, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, dir_s1_d1, -1);
+ test_path(_metadata, dir_s0_d1, 0);
+ test_path(_metadata, dir_s3_d1, 0);
+}
+
+TEST_F(layout1, rule_over_mountpoint)
+{
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s4_d1, dir_s0_d1, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, dir_s4_d2, 0);
+ test_path(_metadata, dir_s0_d1, 0);
+ test_path(_metadata, dir_s4_d1, 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)
+{
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ "/", NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, "/", 0);
+ test_path(_metadata, dir_s0_d1, 0);
+}
+
+TEST_F(layout1, rule_inside_mount_ns)
+{
+ ASSERT_NE(-1, mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL));
+ ASSERT_NE(-1, syscall(SYS_pivot_root, dir_s3_d1, dir_s3_d2));
+ ASSERT_NE(-1, chdir("/"));
+
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ "b3", NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ enforce_ruleset(_metadata, ruleset_fd);
+ EXPECT_EQ(0, close(ruleset_fd));
+
+ test_path(_metadata, "b3", 0);
+ test_path(_metadata, "/", -1);
+}
+
+TEST_F(layout1, mount_and_pivot)
+{
+ int ruleset_fd = create_ruleset(_metadata,
+ (const char *const []){ dir_s3_d1, NULL });
+ 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_s3_d1, dir_s3_d2));
+}
+
+enum relative_access {
+ REL_OPEN,
+ REL_CHDIR,
+ REL_CHROOT,
+};
+
+static void check_access(struct __test_metadata *_metadata,
+ bool enforce, enum relative_access rel)
+{
+ int dirfd;
+ int ruleset_fd = -1;
+
+ if (enforce) {
+ ruleset_fd = create_ruleset(_metadata, (const char *const []){
+ dir_s0_d2, dir_s1_d1, NULL });
+ ASSERT_NE(-1, ruleset_fd);
+ if (rel == REL_CHROOT)
+ ASSERT_NE(-1, chdir(dir_s0_d2));
+ enforce_ruleset(_metadata, ruleset_fd);
+ } else if (rel == REL_CHROOT)
+ ASSERT_NE(-1, chdir(dir_s0_d2));
+ switch (rel) {
+ case REL_OPEN:
+ dirfd = open(dir_s0_d2, O_DIRECTORY);
+ ASSERT_NE(-1, dirfd);
+ break;
+ case REL_CHDIR:
+ ASSERT_NE(-1, chdir(dir_s0_d2));
+ dirfd = AT_FDCWD;
+ break;
+ case REL_CHROOT:
+ ASSERT_NE(-1, chroot(".")) {
+ TH_LOG("Failed to chroot: %s\n", strerror(errno));
+ }
+ dirfd = AT_FDCWD;
+ break;
+ default:
+ ASSERT_TRUE(false);
+ return;
+ }
+
+ test_path_rel(_metadata, dirfd, "..", (rel == REL_CHROOT) ? 0 : -1);
+ test_path_rel(_metadata, dirfd, ".", 0);
+ if (rel != REL_CHROOT) {
+ test_path_rel(_metadata, dirfd, "./c0", 0);
+ test_path_rel(_metadata, dirfd, "../../" TMP_PREFIX "a1", 0);
+ test_path_rel(_metadata, dirfd, "../../" TMP_PREFIX "a2", -1);
+ }
+
+ if (rel == REL_OPEN)
+ EXPECT_EQ(0, close(dirfd));
+ if (enforce)
+ EXPECT_EQ(0, close(ruleset_fd));
+}
+
+TEST_F(layout1, deny_open)
+{
+ check_access(_metadata, true, REL_OPEN);
+}
+
+TEST_F(layout1, deny_chdir)
+{
+ check_access(_metadata, true, REL_CHDIR);
+}
+
+TEST_F(layout1, deny_chroot)
+{
+ check_access(_metadata, true, REL_CHROOT);
+}
+
+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..fcdb41e172d1
--- /dev/null
+++ b/tools/testing/selftests/landlock/test_ptrace.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 "test.h"
+
+static void create_domain(struct __test_metadata *_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,
+ };
+ struct landlock_attr_path_beneath path_beneath = {
+ .allowed_access = LANDLOCK_ACCESS_FS_READ,
+ };
+
+ 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 *_metadata,
+ bool domain_both, bool domain_parent, 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
--
2.25.0
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