iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

selftests/landlock: Add layout1.refer_mount_root

Browse Source 
Add tests to check error codes when linking or renaming a mount root
directory.  This previously triggered a kernel warning, but it is fixed
with the previous commit.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20240516181935.1645983-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
This commit is contained in:
Mickaël Salaün 2024-05-16 20:19:35 +02:00
parent 88da52ccd6
commit 0055f53aac
No known key found for this signature in database
GPG Key ID: E5E3D0E88C82F6D2
1 changed files with 45 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
tools/testing/selftests/landlock/fs_test.c
View File

@ -35,6 +35,7 @@
* See https://sourceware.org/glibc/wiki/Synchronizing_Headers.
*/
#include <linux/fs.h>
#include <linux/mount.h>
#include "common.h"
@ -47,6 +48,13 @@ int renameat2(int olddirfd, const char *oldpath, int newdirfd,
}
#endif
#ifndef open_tree
int open_tree(int dfd, const char *filename, unsigned int flags)
{
return syscall(__NR_open_tree, dfd, filename, flags);
}
#endif
#ifndef RENAME_EXCHANGE
#define RENAME_EXCHANGE (1 << 1)
#endif
@ -2400,6 +2408,43 @@ TEST_F_FORK(layout1, refer_denied_by_default4)
layer_dir_s1d1_refer);
}
/*
* Tests walking through a denied root mount.
*/
TEST_F_FORK(layout1, refer_mount_root_deny)
{
const struct landlock_ruleset_attr ruleset_attr = {
.handled_access_fs = LANDLOCK_ACCESS_FS_MAKE_DIR,
};
int root_fd, ruleset_fd;
/* Creates a mount object from a non-mount point. */
set_cap(_metadata, CAP_SYS_ADMIN);
root_fd =
open_tree(AT_FDCWD, dir_s1d1,
AT_EMPTY_PATH | OPEN_TREE_CLONE | OPEN_TREE_CLOEXEC);
clear_cap(_metadata, CAP_SYS_ADMIN);
ASSERT_LE(0, root_fd);
ruleset_fd =
landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
ASSERT_LE(0, ruleset_fd);
ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
EXPECT_EQ(0, close(ruleset_fd));
/* Link denied by Landlock: EACCES. */
EXPECT_EQ(-1, linkat(root_fd, ".", root_fd, "does_not_exist", 0));
EXPECT_EQ(EACCES, errno);
/* renameat2() always returns EBUSY. */
EXPECT_EQ(-1, renameat2(root_fd, ".", root_fd, "does_not_exist", 0));
EXPECT_EQ(EBUSY, errno);
EXPECT_EQ(0, close(root_fd));
}
TEST_F_FORK(layout1, reparent_link)
{
const struct rule layer1[] = {