Unverified Commit 35ca4239 authored by Mickaël Salaün's avatar Mickaël Salaün
Browse files

selftests/landlock: Add hostfs tests 

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.

Link: https://lore.kernel.org/r/20230612191430.339153-7-mic@digikod.net


Signed-off-by: default avatarMickaël Salaün <mic@digikod.net>
parent 04f9070e

tools/testing/selftests/landlock/config.um

0 → 100644
+1 −0
Original line number Diff line number Diff line 
CONFIG_HOSTFS=y

tools/testing/selftests/landlock/fs_test.c

+27 −1
Original line number Diff line number Diff line
@@ -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)");

	}