[LTP] [PATCH v5 5/6] Add landlock05 test

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

This test verifies LANDLOCK_ACCESS_FS_REFER access in the
landlock sandbox. The feature is available since kernel 5.19.

Reviewed-by: Li Wang <liwang@redhat.com>
Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                                |   1 +
 testcases/kernel/syscalls/landlock/.gitignore   |   1 +
 testcases/kernel/syscalls/landlock/landlock05.c | 118 ++++++++++++++++++++++++
 3 files changed, 120 insertions(+)

diff --git a/runtest/syscalls b/runtest/syscalls
index 67b2e2758..6522f5bc7 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -700,6 +700,7 @@ landlock01 landlock01
 landlock02 landlock02
 landlock03 landlock03
 landlock04 landlock04
+landlock05 landlock05
 
 lchown01 lchown01
 lchown01_16 lchown01_16
diff --git a/testcases/kernel/syscalls/landlock/.gitignore b/testcases/kernel/syscalls/landlock/.gitignore
index 4fe8d7cba..a7ea6be2e 100644
--- a/testcases/kernel/syscalls/landlock/.gitignore
+++ b/testcases/kernel/syscalls/landlock/.gitignore
@@ -3,3 +3,4 @@ landlock01
 landlock02
 landlock03
 landlock04
+landlock05
diff --git a/testcases/kernel/syscalls/landlock/landlock05.c b/testcases/kernel/syscalls/landlock/landlock05.c
new file mode 100644
index 000000000..5083fe12b
--- /dev/null
+++ b/testcases/kernel/syscalls/landlock/landlock05.c
@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2024 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * This test verifies LANDLOCK_ACCESS_FS_REFER access in the
+ * landlock sandbox.
+ *
+ * [Algorithm]
+ *
+ * - apply LANDLOCK_ACCESS_FS_REFER in the folder1
+ * - apply LANDLOCK_ACCESS_FS_REFER in the folder2
+ * - create folder3
+ * - verify that file can be moved from folder1 to folder2
+ * - verify that file can't be moved from folder1 to folder3
+ */
+
+#include "landlock_common.h"
+
+#define MNTPOINT "sandbox"
+#define DIR1 MNTPOINT"/folder1"
+#define DIR2 MNTPOINT"/folder2"
+#define DIR3 MNTPOINT"/folder3"
+#define FILENAME1 DIR1"/file"
+#define FILENAME2 DIR2"/file"
+#define FILENAME3 DIR3"/file"
+
+static struct landlock_ruleset_attr *ruleset_attr;
+static struct landlock_path_beneath_attr *path_beneath_attr;
+
+static void run(void)
+{
+	if (SAFE_FORK())
+		return;
+
+	TST_EXP_PASS(rename(FILENAME1, FILENAME2));
+	if (TST_RET == -1)
+		return;
+
+	TST_EXP_FAIL(rename(FILENAME2, FILENAME3), EXDEV);
+	TST_EXP_PASS(rename(FILENAME2, FILENAME1));
+
+	_exit(0);
+}
+
+static void setup(void)
+{
+	int abi;
+	int ruleset_fd;
+
+	abi = verify_landlock_is_enabled();
+	if (abi < 2)
+		tst_brk(TCONF, "LANDLOCK_ACCESS_FS_REFER is unsupported on ABI < 2");
+
+	SAFE_MKDIR(DIR1, 0640);
+	SAFE_MKDIR(DIR2, 0640);
+	SAFE_MKDIR(DIR3, 0640);
+	SAFE_TOUCH(FILENAME1, 0640, NULL);
+
+	tst_res(TINFO, "Applying LANDLOCK_ACCESS_FS_REFER");
+
+	ruleset_attr->handled_access_fs =
+		LANDLOCK_ACCESS_FS_READ_FILE |
+		LANDLOCK_ACCESS_FS_WRITE_FILE |
+		LANDLOCK_ACCESS_FS_REFER;
+
+	ruleset_fd = SAFE_LANDLOCK_CREATE_RULESET(
+		ruleset_attr, sizeof(struct landlock_ruleset_attr), 0);
+
+	apply_landlock_rule(
+		path_beneath_attr,
+		ruleset_fd,
+		LANDLOCK_ACCESS_FS_REFER,
+		DIR1);
+
+	apply_landlock_rule(
+		path_beneath_attr,
+		ruleset_fd,
+		LANDLOCK_ACCESS_FS_REFER,
+		DIR2);
+
+	enforce_ruleset(ruleset_fd);
+
+	SAFE_CLOSE(ruleset_fd);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.needs_tmpdir = 1,
+	.needs_root = 1,
+	.forks_child = 1,
+	.needs_kconfigs = (const char *[]) {
+		"CONFIG_SECURITY_LANDLOCK=y",
+		NULL
+	},
+	.bufs = (struct tst_buffers []) {
+		{&ruleset_attr, .size = sizeof(struct landlock_ruleset_attr)},
+		{&path_beneath_attr, .size = sizeof(struct landlock_path_beneath_attr)},
+		{},
+	},
+	.caps = (struct tst_cap []) {
+		TST_CAP(TST_CAP_REQ, CAP_SYS_ADMIN),
+		{}
+	},
+	.format_device = 1,
+	.mount_device = 1,
+	.mntpoint = MNTPOINT,
+	.all_filesystems = 1,
+	.skip_filesystems = (const char *[]) {
+		"vfat",
+		"exfat",
+		NULL
+	},
+};

-- 
2.43.0