Add tests for the hostfs filesystems to make sure it has a consistent inode management, which is required for Landlock's file hierarchy identification. This adds 5 new tests for layout3_fs with the hostfs variant.
Add hostfs to the new (architecture-specific) config.um file.
The hostfs filesystem, only available for an User-Mode Linux kernel, is special because we cannot explicitly mount it. The layout3_fs.hostfs variant tests are skipped if the current test directory is not backed by this filesystem.
The layout3_fs.hostfs.tag_inode_dir_child and layout3_fs.hostfs.tag_inode_file tests pass thanks to a previous commit fixing hostfs inode management. Without this fix, the deny-by-default policy would apply and all access requests would be denied.
Signed-off-by: Mickaël Salaün mic@digikod.net --- tools/testing/selftests/landlock/config.um | 1 + tools/testing/selftests/landlock/fs_test.c | 28 +++++++++++++++++++++- 2 files changed, 28 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/landlock/config.um
diff --git a/tools/testing/selftests/landlock/config.um b/tools/testing/selftests/landlock/config.um new file mode 100644 index 000000000000..40937c0395d6 --- /dev/null +++ b/tools/testing/selftests/landlock/config.um @@ -0,0 +1 @@ +CONFIG_HOSTFS=y diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 2911b5241583..83d565569512 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -10,6 +10,7 @@ #define _GNU_SOURCE #include <fcntl.h> #include <linux/landlock.h> +#include <linux/magic.h> #include <sched.h> #include <stdio.h> #include <string.h> @@ -19,6 +20,7 @@ #include <sys/sendfile.h> #include <sys/stat.h> #include <sys/sysmacros.h> +#include <sys/vfs.h> #include <unistd.h>
#include "common.h" @@ -135,6 +137,19 @@ static bool supports_filesystem(const char *const filesystem) return res; }
+static bool cwd_matches_fs(unsigned int fs_magic) +{ + struct statfs statfs_buf; + + if (!fs_magic) + return true; + + if (statfs(".", &statfs_buf)) + return true; + + return statfs_buf.f_type == fs_magic; +} + static void mkdir_parents(struct __test_metadata *const _metadata, const char *const path) { @@ -4500,6 +4515,7 @@ FIXTURE_VARIANT(layout3_fs) { const struct mnt_opt mnt; const char *const file_path; + unsigned int cwd_fs_magic; };
/* clang-format off */ @@ -4538,13 +4554,23 @@ FIXTURE_VARIANT_ADD(layout3_fs, sysfs) { .file_path = TMP_DIR "/kernel/notes", };
+FIXTURE_VARIANT_ADD(layout3_fs, hostfs) { + .mnt = { + .source = TMP_DIR, + .flags = MS_BIND, + }, + .file_path = TMP_DIR "/dir/file", + .cwd_fs_magic = HOSTFS_SUPER_MAGIC, +}; + FIXTURE_SETUP(layout3_fs) { struct stat statbuf; const char *slash; size_t dir_len;
- if (!supports_filesystem(variant->mnt.type)) { + if (!supports_filesystem(variant->mnt.type) || + !cwd_matches_fs(variant->cwd_fs_magic)) { self->skip_test = true; SKIP(return, "this filesystem is not supported (setup)"); }