diff --git a/include/net/tcp.h b/include/net/tcp.h
index a5af6be3a572..dd99679e2e51 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1161,6 +1161,7 @@ static inline void tcp_prequeue_init(struct tcp_sock *tp)
 }
 
 bool tcp_prequeue(struct sock *sk, struct sk_buff *skb);
+bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb);
 
 #undef STATE_TRACE
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index ad41e8ecf796..53e80cd004b6 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1532,6 +1532,34 @@ bool tcp_prequeue(struct sock *sk, struct sk_buff *skb)
 }
 EXPORT_SYMBOL(tcp_prequeue);
 
+bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb)
+{
+	u32 limit = sk->sk_rcvbuf + sk->sk_sndbuf;
+
+	/* Only socket owner can try to collapse/prune rx queues
+	 * to reduce memory overhead, so add a little headroom here.
+	 * Few sockets backlog are possibly concurrently non empty.
+	 */
+	limit += 64*1024;
+
+	/* In case all data was pulled from skb frags (in __pskb_pull_tail()),
+	 * we can fix skb->truesize to its real value to avoid future drops.
+	 * This is valid because skb is not yet charged to the socket.
+	 * It has been noticed pure SACK packets were sometimes dropped
+	 * (if cooked by drivers without copybreak feature).
+	 */
+	if (!skb->data_len)
+		skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
+
+	if (unlikely(sk_add_backlog(sk, skb, limit))) {
+		bh_unlock_sock(sk);
+		__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP);
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL(tcp_add_backlog);
+
 /*
  *	From tcp_input.c
  */
@@ -1662,10 +1690,7 @@ process:
 	if (!sock_owned_by_user(sk)) {
 		if (!tcp_prequeue(sk, skb))
 			ret = tcp_v4_do_rcv(sk, skb);
-	} else if (unlikely(sk_add_backlog(sk, skb,
-					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
-		bh_unlock_sock(sk);
-		__NET_INC_STATS(net, LINUX_MIB_TCPBACKLOGDROP);
+	} else if (tcp_add_backlog(sk, skb)) {
 		goto discard_and_relse;
 	}
 	bh_unlock_sock(sk);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index e4f55683af31..5bf460bd299f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1467,10 +1467,7 @@ process:
 	if (!sock_owned_by_user(sk)) {
 		if (!tcp_prequeue(sk, skb))
 			ret = tcp_v6_do_rcv(sk, skb);
-	} else if (unlikely(sk_add_backlog(sk, skb,
-					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
-		bh_unlock_sock(sk);
-		__NET_INC_STATS(net, LINUX_MIB_TCPBACKLOGDROP);
+	} else if (tcp_add_backlog(sk, skb)) {
 		goto discard_and_relse;
 	}
 	bh_unlock_sock(sk);