selinux: always fill AVC decision in avc_has_perm_noaudit()

avc_has_perm_noaudit() is documented to return a copy of the access
decision in @avd, but its early return for an empty requested permission
set leaves the buffer untouched.  All callers pass an uninitialized
stack variable and afterwards feed it to avc_audit(), and the inode hook
even stores it in the per-task decision cache.

Fill in a deny-all, audit-all decision, similar to avd_init(), so every
caller receives a defined value at no cost on the hot path.

Cc: stable@vger.kernel.org
Fixes: e6f2f381e4 ("selinux: replace BUG_ONs with WARN_ONs in avc.c")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Christian Göttsche 2026-09-03 13:43:38 +02:00 • committed by Paul Moore
commit 8861db3051