keys: Timestamp new keys

[ Upstream commit 7c1857bdbdf1e4c541e45eab477ee23ed4333ea4 ]

Set the timestamp on new keys rather than leaving it unset.

Fixes: 31d5a79d7f3d ("KEYS: Do LRU discard in full keyrings")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/security/keys/key.c b/security/keys/key.c
index 7276d1a..280b4fe 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -296,6 +296,7 @@
 	key->gid = gid;
 	key->perm = perm;
 	key->restrict_link = restrict_link;
+	key->last_used_at = ktime_get_real_seconds();
 
 	if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;