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| author |   Mickaël Salaün <mic@digikod.net> | 2025-06-06 13:08:09 +0200 |
|---|---|---|
| committer | Mickaël Salaün <mic@digikod.net> | 2025-06-19 13:55:41 +0200 |
| commit | dae01387e6a9bbce31f6c62839733ab8b63e16f3 (patch) | |
| tree | e214d5642d8548ede63cc8a367c9687e58f9e56f | |
| parent | selftests/landlock: Fix build of audit_test (diff) | |
| download | wireguard-linux-dae01387e6a9bbce31f6c62839733ab8b63e16f3.tar.xz wireguard-linux-dae01387e6a9bbce31f6c62839733ab8b63e16f3.zip | |
selftests/landlock: Add test to check rule tied to covered mount point
This test checks that a rule on a directory used as a mount point does
not grant access to the mount covering it. It is a generalization of
the bind mount case in layout3_fs.hostfs.release_inodes [1] that tests
hidden mount points.
Cc: Günther Noack <gnoack@google.com>
Cc: Song Liu <song@kernel.org>
Cc: Tingmao Wang <m@maowtm.org>
Link: https://lore.kernel.org/r/20250606.zo5aekae6Da6@digikod.net [1]
Link: https://lore.kernel.org/r/20250606110811.211297-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
| -rw-r--r-- | tools/testing/selftests/landlock/fs_test.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 73729382d40f..fa0f18ec62c4 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -1832,6 +1832,46 @@ TEST_F_FORK(layout1, release_inodes) ASSERT_EQ(ENOENT, test_open(dir_s3d3, O_RDONLY)); } +/* + * This test checks that a rule on a directory used as a mount point does not + * grant access to the mount covering it. It is a generalization of the bind + * mount case in layout3_fs.hostfs.release_inodes that tests hidden mount points. + */ +TEST_F_FORK(layout1, covered_rule) +{ + const struct rule layer1[] = { + { + .path = dir_s3d2, + .access = LANDLOCK_ACCESS_FS_READ_DIR, + }, + {}, + }; + int ruleset_fd; + + /* Unmount to simplify FIXTURE_TEARDOWN. */ + set_cap(_metadata, CAP_SYS_ADMIN); + ASSERT_EQ(0, umount(dir_s3d2)); + clear_cap(_metadata, CAP_SYS_ADMIN); + + /* Creates a ruleset with the future hidden directory. */ + ruleset_fd = + create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_DIR, layer1); + ASSERT_LE(0, ruleset_fd); + + /* Covers with a new mount point. */ + set_cap(_metadata, CAP_SYS_ADMIN); + ASSERT_EQ(0, mount_opt(&mnt_tmp, dir_s3d2)); + clear_cap(_metadata, CAP_SYS_ADMIN); + + ASSERT_EQ(0, test_open(dir_s3d2, O_RDONLY)); + + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + /* Checks that access to the new mount point is denied. */ + ASSERT_EQ(EACCES, test_open(dir_s3d2, O_RDONLY)); +} + enum relative_access { REL_OPEN, REL_CHDIR, |