1 files changed, 17 insertions, 14 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 4522579aaca2..0ebc33d1c9e5 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * INET		An implementation of the TCP/IP protocol suite for the LINUX
  *		operating system.  INET is implemented using the  BSD Socket
@@ -52,12 +53,8 @@ void tcp_mstamp_refresh(struct tcp_sock *tp)
 {
 	u64 val = tcp_clock_ns();
 
-	if (val > tp->tcp_clock_cache)
-		tp->tcp_clock_cache = val;
-
-	val = div_u64(val, NSEC_PER_USEC);
-	if (val > tp->tcp_mstamp)
-		tp->tcp_mstamp = val;
+	tp->tcp_clock_cache = val;
+	tp->tcp_mstamp = div_u64(val, NSEC_PER_USEC);
 }
 
 static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
@@ -1299,6 +1296,12 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue,
 	if (nsize < 0)
 		nsize = 0;
 
+	if (unlikely((sk->sk_wmem_queued >> 1) > sk->sk_sndbuf &&
+		     tcp_queue != TCP_FRAG_IN_WRITE_QUEUE)) {
+		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPWQUEUETOOBIG);
+		return -ENOMEM;
+	}
+
 	if (skb_unclone(skb, gfp))
 		return -ENOMEM;
 
@@ -1457,8 +1460,7 @@ static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu)
 	mss_now -= icsk->icsk_ext_hdr_len;
 
 	/* Then reserve room for full set of TCP options and 8 bytes of data */
-	if (mss_now < 48)
-		mss_now = 48;
+	mss_now = max(mss_now, sock_net(sk)->ipv4.sysctl_tcp_min_snd_mss);
 	return mss_now;
 }
 
@@ -2750,7 +2752,7 @@ static bool tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
 		if (next_skb_size <= skb_availroom(skb))
 			skb_copy_bits(next_skb, 0, skb_put(skb, next_skb_size),
 				      next_skb_size);
-		else if (!skb_shift(skb, next_skb, next_skb_size))
+		else if (!tcp_skb_shift(skb, next_skb, 1, next_skb_size))
 			return false;
 	}
 	tcp_highest_sack_replace(sk, next_skb, skb);
@@ -3092,7 +3094,6 @@ void tcp_send_fin(struct sock *sk)
 		tskb = skb_rb_last(&sk->tcp_rtx_queue);
 
 	if (tskb) {
-coalesce:
 		TCP_SKB_CB(tskb)->tcp_flags |= TCPHDR_FIN;
 		TCP_SKB_CB(tskb)->end_seq++;
 		tp->write_seq++;
@@ -3108,11 +3109,9 @@ coalesce:
 		}
 	} else {
 		skb = alloc_skb_fclone(MAX_TCP_HEADER, sk->sk_allocation);
-		if (unlikely(!skb)) {
-			if (tskb)
-				goto coalesce;
+		if (unlikely(!skb))
 			return;
-		}
+
 		INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
 		skb_reserve(skb, MAX_TCP_HEADER);
 		sk_forced_mem_schedule(sk, skb->truesize);
@@ -3254,7 +3253,11 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
 		skb->skb_mstamp_ns = cookie_init_timestamp(req);
 	else
 #endif
+	{
 		skb->skb_mstamp_ns = tcp_clock_ns();
+		if (!tcp_rsk(req)->snt_synack) /* Timestamp first SYNACK */
+			tcp_rsk(req)->snt_synack = tcp_skb_timestamp_us(skb);
+	}
 
 #ifdef CONFIG_TCP_MD5SIG
 	rcu_read_lock();