net/ieee802154: Do not unreference one time too many a fragmented packet

In case the current packet is the same as the cached one, let's not
unreference it while clearing the cache.

Signed-off-by: Tomasz Bursztyka <[email protected]>

Author: Tomasz Bursztyka

subsys/net/l2/ieee802154/ieee802154_fragment.c

@@ -530,8 +530,14 @@ static inline enum net_verdict fragment_add_to_cache(struct net_pkt *pkt)
 			/* Assign buffer back to input packet. */
 			pkt->buffer = cache->pkt->buffer;
 			cache->pkt->buffer = NULL;
+		} else {
+			/* in case pkt == cache->pkt, we don't want
+			 * to unref it while clearing the cach.
+			 */
+			cache->pkt = NULL;
 		}
 
+
 		fragment_reconstruct_packet(pkt);
 
 		/* Once reassemble is done, cache is no longer needed. */