[PATCH v1 1/2] selftests/landlock: Add tests to check undefined rule's access rights

[Mickaël Salaün]

On Fri, Nov 24, 2023 at 06:07:05PM +0100, Günther Noack wrote:
> On Mon, Nov 20, 2023 at 08:39:13PM +0100, Mickaël Salaün wrote:
> > Extend two tests to make sure that we cannot add a rule with access
> > rights that are undefined:
> > * fs: layout1.file_and_dir_access_rights
> > * net: mini.network_access_rights
> > 
> > The checks test all 64 bits access right values until it overflows.
> > 
> > Replace one ASSERT with EXPECT in layout1.file_and_dir_access_rights .
> > 
> > Cc: Günther Noack <gnoack at google.com>
> > Cc: Konstantin Meskhidze <konstantin.meskhidze at huawei.com>
> > Signed-off-by: Mickaël Salaün <mic at digikod.net>
> > ---
> >  tools/testing/selftests/landlock/fs_test.c  | 17 ++++++++++++-----
> >  tools/testing/selftests/landlock/net_test.c | 17 ++++++++++-------
> >  2 files changed, 22 insertions(+), 12 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
> > index 18e1f86a6234..d77155d75de5 100644
> > --- a/tools/testing/selftests/landlock/fs_test.c
> > +++ b/tools/testing/selftests/landlock/fs_test.c
> > @@ -548,7 +548,6 @@ TEST_F_FORK(layout1, inval)
> >  TEST_F_FORK(layout1, file_and_dir_access_rights)
> >  {
> >  	__u64 access;
> > -	int err;
> >  	struct landlock_path_beneath_attr path_beneath_file = {},
> >  					  path_beneath_dir = {};
> >  	struct landlock_ruleset_attr ruleset_attr = {
> > @@ -568,11 +567,19 @@ TEST_F_FORK(layout1, file_and_dir_access_rights)
> >  		open(dir_s1d2, O_PATH | O_DIRECTORY | O_CLOEXEC);
> >  	ASSERT_LE(0, path_beneath_dir.parent_fd);
> >  
> > -	for (access = 1; access <= ACCESS_LAST; access <<= 1) {
> > +	for (access = 1; access > 0; access <<= 1) {
> > +		int err;
> > +
> >  		path_beneath_dir.allowed_access = access;
> > -		ASSERT_EQ(0, landlock_add_rule(ruleset_fd,
> > -					       LANDLOCK_RULE_PATH_BENEATH,
> > -					       &path_beneath_dir, 0));
> > +		err = landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
> > +					&path_beneath_dir, 0);
> > +		if (access <= ACCESS_LAST) {
> > +			EXPECT_EQ(0, err);
> > +		} else {
> > +			EXPECT_EQ(-1, err);
> > +			EXPECT_EQ(EINVAL, errno);
> > +			continue;
> > +		}
> 
> Style question: why not have two loops next to each other?  You could keep the
> old loop from 1 to ACCESS_LAST and then have a separate one from ACCESS_LAST+1
> onwards.  Then you would not need to put logic inside the loop; it might reduce
> nesting a bit, and each loop individually might be slightly easier to grasp.
> 
> I was initially a bit confused why the other landlock_add_rule() call for the
> directory doesn't need the same change. That is clear to me after looking at the
> code a few seconds longer, but it might be slightly simpler with two separate
> loops.

Indeed, I'll send a v2.

> 
> But this is a minor nit.
> 
> Reviewed-by: Günther Noack <gnoack at google.com>
> 
> Thanks!
> —Günther
>