Revert "net:tipc: Fix a double free in tipc_sk_mcast_rcv"

stable inclusion
from stable-5.10.42
commit 0aa2212940b85f71b81383e6bfdf70c439eeff04
bugzilla: 55093
CVE: NA

--------------------------------

commit 75016891 upstream.

This reverts commit 6bf24dc0.
Above fix is not correct and caused memory leak issue.

Fixes: 6bf24dc0 ("net:tipc: Fix a double free in tipc_sk_mcast_rcv")
Acked-by: NJon Maloy <jmaloy@redhat.com>
Acked-by: NTung Nguyen <tung.q.nguyen@dektech.com.au>
Signed-off-by: NHoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/tipc/socket.c

@@ -1244,7 +1244,10 @@ void tipc_sk_mcast_rcv(struct net *net, struct sk_buff_head *arrvq,
 		spin_lock_bh(&inputq->lock);
 		if (skb_peek(arrvq) == skb) {
 			skb_queue_splice_tail_init(&tmpq, inputq);
-			__skb_dequeue(arrvq);
+			/* Decrease the skb's refcnt as increasing in the
+			 * function tipc_skb_peek
+			 */
+			kfree_skb(__skb_dequeue(arrvq));
 		}
 		spin_unlock_bh(&inputq->lock);
 		__skb_queue_purge(&tmpq);