--- zzzz-none-000/linux-4.4.60/net/ipv4/tcp_input.c	2017-04-08 07:53:53.000000000 +0000
+++ wasp-540e-714/linux-4.4.60/net/ipv4/tcp_input.c	2019-07-03 09:21:34.000000000 +0000
@@ -1266,7 +1266,7 @@
 	TCP_SKB_CB(skb)->seq += shifted;
 
 	tcp_skb_pcount_add(prev, pcount);
-	BUG_ON(tcp_skb_pcount(skb) < pcount);
+	WARN_ON_ONCE(tcp_skb_pcount(skb) < pcount);
 	tcp_skb_pcount_add(skb, -pcount);
 
 	/* When we're adding to gso_segs == 1, gso_size will be zero,
@@ -1328,6 +1328,21 @@
 	return !skb_headlen(skb) && skb_is_nonlinear(skb);
 }
 
+int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from,
+		  int pcount, int shiftlen)
+{
+	/* TCP min gso_size is 8 bytes (TCP_MIN_GSO_SIZE)
+	 * Since TCP_SKB_CB(skb)->tcp_gso_segs is 16 bits, we need
+	 * to make sure not storing more than 65535 * 8 bytes per skb,
+	 * even if current MSS is bigger.
+	 */
+	if (unlikely(to->len + shiftlen >= 65535 * TCP_MIN_GSO_SIZE))
+		return 0;
+	if (unlikely(tcp_skb_pcount(to) + pcount > 65535))
+		return 0;
+	return skb_shift(to, from, shiftlen);
+}
+
 /* Try collapsing SACK blocks spanning across multiple skbs to a single
  * skb.
  */
@@ -1339,6 +1354,7 @@
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *prev;
 	int mss;
+	int next_pcount;
 	int pcount = 0;
 	int len;
 	int in_sack;
@@ -1433,7 +1449,7 @@
 	if (!after(TCP_SKB_CB(skb)->seq + len, tp->snd_una))
 		goto fallback;
 
-	if (!skb_shift(prev, skb, len))
+	if (!tcp_skb_shift(prev, skb, pcount, len))
 		goto fallback;
 	if (!tcp_shifted_skb(sk, skb, state, pcount, len, mss, dup_sack))
 		goto out;
@@ -1452,11 +1468,11 @@
 		goto out;
 
 	len = skb->len;
-	if (skb_shift(prev, skb, len)) {
-		pcount += tcp_skb_pcount(skb);
-		tcp_shifted_skb(sk, skb, state, tcp_skb_pcount(skb), len, mss, 0);
+	next_pcount = tcp_skb_pcount(skb);
+	if (tcp_skb_shift(prev, skb, next_pcount, len)) {
+		pcount += next_pcount;
+		tcp_shifted_skb(sk, skb, state, next_pcount, len, mss, 0);
 	}
-
 out:
 	state->fack_count += pcount;
 	return prev;
@@ -3818,14 +3834,16 @@
 {
 	const __be32 *ptr = (const __be32 *)(th + 1);
 
-	if (*ptr == htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16)
-			  | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)) {
+	if (net_hdr_word(ptr) ==
+	    htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+		  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)) {
 		tp->rx_opt.saw_tstamp = 1;
 		++ptr;
-		tp->rx_opt.rcv_tsval = ntohl(*ptr);
+		tp->rx_opt.rcv_tsval = get_unaligned_be32(ptr);
 		++ptr;
-		if (*ptr)
-			tp->rx_opt.rcv_tsecr = ntohl(*ptr) - tp->tsoffset;
+		if (net_hdr_word(ptr))
+			tp->rx_opt.rcv_tsecr = get_unaligned_be32(ptr) -
+					       tp->tsoffset;
 		else
 			tp->rx_opt.rcv_tsecr = 0;
 		return true;