1 files changed, 12 insertions, 5 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index e2b4461074da..509912a5ff98 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1298,7 +1298,6 @@ static void __pskb_trim_head(struct sk_buff *skb, int len)
         eat = min_t(int, len, skb_headlen(skb));
         if (eat) {
                 __skb_pull(skb, eat);
-                skb->avail_size -= eat;
                 len -= eat;
                 if (!len)
                         return;
@@ -1810,8 +1809,11 @@ static bool tcp_tso_should_defer(struct sock *sk, struct sk_buff *skb)
                         goto send_now;
         }
 
-        /* Ok, it looks like it is advisable to defer.  */
-        tp->tso_deferred = 1 | (jiffies << 1);
+        /* Ok, it looks like it is advisable to defer.
+         * Do not rearm the timer if already set to not break TCP ACK clocking.
+         */
+        if (!tp->tso_deferred)
+                tp->tso_deferred = 1 | (jiffies << 1);
 
         return true;
 
@@ -2386,8 +2388,12 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
          */
         TCP_SKB_CB(skb)->when = tcp_time_stamp;
 
-        /* make sure skb->data is aligned on arches that require it */
-        if (unlikely(NET_IP_ALIGN && ((unsigned long)skb->data & 3))) {
+        /* make sure skb->data is aligned on arches that require it
+         * and check if ack-trimming & collapsing extended the headroom
+         * beyond what csum_start can cover.
+         */
+        if (unlikely((NET_IP_ALIGN && ((unsigned long)skb->data & 3)) ||
+                     skb_headroom(skb) >= 0xFFFF)) {
                 struct sk_buff *nskb = __pskb_copy(skb, MAX_TCP_HEADER,
                                                    GFP_ATOMIC);
                 return nskb ? tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC) :
@@ -2707,6 +2713,7 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
         skb_reserve(skb, MAX_TCP_HEADER);
 
         skb_dst_set(skb, dst);
+        security_skb_owned_by(skb, sk);
 
         mss = dst_metric_advmss(dst);
         if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)