Named pipes should behave like pipes created with pipe(2),
so we don't want to restrict IOCTLs on them.
Suggested-by: Mickaël Salaün <mic@xxxxxxxxxxx>
Signed-off-by: Günther Noack <gnoack@xxxxxxxxxx>
---
tools/testing/selftests/landlock/fs_test.c | 70 +++++++++++++++++++---
1 file changed, 61 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 9e9b828a898b..ae8b8b412828 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -3922,6 +3922,67 @@ TEST_F_FORK(layout1, o_path_ftruncate_and_ioctl)
ASSERT_EQ(0, close(fd));
}
+static int test_fionread_ioctl(int fd)
+{
+ size_t sz = 0;
+
+ if (ioctl(fd, FIONREAD, &sz) < 0 && errno == EACCES)
+ return errno;
+ return 0;
+}
+
+/*
+ * For named pipes, the same rules should apply as for anonymous pipes.
+ *
+ * That means, if the pipe is opened, we should permit the IOCTLs which are
+ * implemented by pipefifo_fops (fs/pipe.c), even if they were otherwise
+ * forbidden by Landlock policy.
+ */
+TEST_F_FORK(layout1, named_pipe_ioctl)
+{
+ pid_t child_pid;
+ int fd, ruleset_fd;
+ const char *const path = file1_s1d1;
+ const struct landlock_ruleset_attr attr = {
+ .handled_access_fs = LANDLOCK_ACCESS_FS_IOCTL,
+ };
+
+ ASSERT_EQ(0, unlink(path));
+ ASSERT_EQ(0, mkfifo(path, 0600));
+
+ /* 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));
+
+ /* The child process opens the pipe for writing. */
+ child_pid = fork();
+ ASSERT_NE(-1, child_pid);
+ if (child_pid == 0) {
+ fd = open(path, O_WRONLY);
+ close(fd);
+ exit(0);
+ }
+
+ fd = open(path, O_RDONLY);
+ ASSERT_LE(0, fd);
+
+ /* FIONREAD is implemented by pipefifo_fops. */
+ EXPECT_EQ(0, test_fionread_ioctl(fd));
+
+ ASSERT_EQ(0, close(fd));
+ ASSERT_EQ(0, unlink(path));
+
+ /* Under the same conditions, FIONREAD on a regular file fails. */
+ fd = open(file2_s1d1, O_RDONLY);
+ ASSERT_LE(0, fd);
+ EXPECT_EQ(EACCES, test_fionread_ioctl(fd));
+ ASSERT_EQ(0, close(fd));
+
+ ASSERT_EQ(child_pid, waitpid(child_pid, NULL, 0));
+}
+
/* clang-format off */
FIXTURE(ioctl) {};
/* clang-format on */
@@ -4134,15 +4195,6 @@ static int test_fibmap_ioctl(int fd)
return 0;
}
-static int test_fionread_ioctl(int fd)
-{
- size_t sz = 0;
-
- if (ioctl(fd, FIONREAD, &sz) < 0 && errno == EACCES)
- return errno;
- return 0;
-}
-
TEST_F_FORK(ioctl, handle_dir_access_file)
{
const int flag = 0;
--
2.43.0.687.g38aa6559b0-goog
