selinux: ensure we cleanup the internal AVC counters on error in avc_update()

BugLink: https://bugs.launchpad.net/bugs/1868627

[ Upstream commit 030b995a ]

In AVC update we don't call avc_node_kill() when avc_xperms_populate()
fails, resulting in the avc->avc_cache.active_nodes counter having a
false value.  In last patch this changes was missed , so correcting it.

Fixes: fa1aa143 ("selinux: extended permissions for ioctls")
Signed-off-by: Jaihind Yadav <jaihindyadav@codeaurora.org>
Signed-off-by: Ravi Kumar Siddojigari <rsiddoji@codeaurora.org>
[PM: merge fuzz, minor description cleanup]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

security/selinux/avc.c

@@ -865,7 +865,7 @@ static int avc_update_node(u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid,
 	if (orig->ae.xp_node) {
 		rc = avc_xperms_populate(node, orig->ae.xp_node);
 		if (rc) {
-			kmem_cache_free(avc_node_cachep, node);
+			avc_node_kill(node);
 			goto out_unlock;
 		}
 	}