[LTP] [PATCH ltp] IMA: Add tests for uid, gid, fowner, and fgroup options

[Alex Henrie <alexh@vpitech.com>]

On Thu, 9 Sep 2021 22:21:22 +0200
Petr Vorel <pvorel@suse.cz> wrote:

> > Requires "ima: add gid support".
> I haven't test the patch yet, but LTP supports (unlike kselftest) various kernel
> versions. Thus there should be some check to prevent old kernels failing.
> You could certainly wrap new things with if tst_kvcmp. If there is a chance new
> functionality can be detected, we prefer it because various features are
> sometimes backported to enterprise distros' kernels.
> 
> Also, adding new test ima_measurements02.sh with TST_MIN_KVER would also work,
> although for IMA tests I usually kept everything in a single file.

I'll add a tst_kvcmp check under the assumption that this feature will
be added before Linux 5.15.

> > +++ b/testcases/kernel/security/integrity/ima/tests/ima_measurements.sh
> > @@ -8,6 +8,7 @@
> 
> >  TST_NEEDS_CMDS="awk cut sed"
> You should add sudo:
> 
> TST_NEEDS_CMDS="awk cut sed sudo"

Will do.

> >  TST_SETUP="setup"
> > +TST_CLEANUP="cleanup"
> >  TST_CNT=3
> >  TST_NEEDS_DEVICE=1
> 
> > @@ -20,6 +21,13 @@ setup()
> >  	TEST_FILE="$PWD/test.txt"
> >  	POLICY="$IMA_DIR/policy"
> >  	[ -f "$POLICY" ] || tst_res TINFO "not using default policy"
> > +
> > +	cat $IMA_POLICY > policy-original
> This might not work if CONFIG_IMA_READ_POLICY is not set. There is
> check_policy_readable() helper in ima_setup.sh. Is it really needed anyway?

It looks like CONFIG_IMA_WRITE_POLICY only makes it possible to add new
rules at runtime, not remove them, so the cleanup code didn't actually
work. I'll remove it.

> > +}
> > +
> > +cleanup()
> > +{
> > +	cat policy-original > $IMA_POLICY
> Again, this will not work if CONFIG_IMA_WRITE_POLICY not set.
> And this is very likely not to be set.

The new tests require the policy to be writable. I'll move the
check_policy_writable function from ima_policy.sh to ima_setup.sh and
use it in ima_measurements.sh as well.

Thanks for the feedback,

-Alex