From 7954a1d155975a3fbc9570151358738f59605121 Mon Sep 17 00:00:00 2001 From: =?utf8?q?G=C3=BCnther=20Noack?= Date: Fri, 19 Apr 2024 16:11:15 +0000 Subject: [PATCH] selftests/landlock: Test ioctl(2) and ftruncate(2) with open(O_PATH) MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit ioctl(2) and ftruncate(2) operations on files opened with O_PATH should always return EBADF, independent of the LANDLOCK_ACCESS_FS_TRUNCATE and LANDLOCK_ACCESS_FS_IOCTL_DEV access rights in that file hierarchy. Suggested-by: Mickaël Salaün Signed-off-by: Günther Noack Link: https://lore.kernel.org/r/20240419161122.2023765-5-gnoack@google.com Signed-off-by: Mickaël Salaün --- tools/testing/selftests/landlock/fs_test.c | 40 ++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 193dc58bac7a9..cb6e9330fcf56 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -3902,6 +3902,46 @@ static int test_fionread_ioctl(int fd) return 0; } +TEST_F_FORK(layout1, o_path_ftruncate_and_ioctl) +{ + const struct landlock_ruleset_attr attr = { + .handled_access_fs = ACCESS_ALL, + }; + int ruleset_fd, fd; + + /* + * Checks that for files opened with O_PATH, both ioctl(2) and + * ftruncate(2) yield EBADF, as it is documented in open(2) for the + * O_PATH flag. + */ + fd = open(dir_s1d1, O_PATH | O_CLOEXEC); + ASSERT_LE(0, fd); + + EXPECT_EQ(EBADF, test_ftruncate(fd)); + EXPECT_EQ(EBADF, test_fs_ioc_getflags_ioctl(fd)); + + ASSERT_EQ(0, close(fd)); + + /* Enables Landlock. */ + ruleset_fd = landlock_create_ruleset(&attr, sizeof(attr), 0); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + /* + * Checks that after enabling Landlock, + * - the file can still be opened with O_PATH + * - both ioctl and truncate still yield EBADF (not EACCES). + */ + fd = open(dir_s1d1, O_PATH | O_CLOEXEC); + ASSERT_LE(0, fd); + + EXPECT_EQ(EBADF, test_ftruncate(fd)); + EXPECT_EQ(EBADF, test_fs_ioc_getflags_ioctl(fd)); + + ASSERT_EQ(0, close(fd)); +} + /* clang-format off */ FIXTURE(ioctl) {}; -- 2.30.2