diff options
| -rw-r--r-- | net/ipv4/tcp_offload.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c index 11f69bbf9307..b6a2aa1dcf56 100644 --- a/net/ipv4/tcp_offload.c +++ b/net/ipv4/tcp_offload.c @@ -149,11 +149,19 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb, * is freed by GSO engine */ if (copy_destructor) { + int delta; + swap(gso_skb->sk, skb->sk); swap(gso_skb->destructor, skb->destructor); sum_truesize += skb->truesize; - refcount_add(sum_truesize - gso_skb->truesize, - &skb->sk->sk_wmem_alloc); + delta = sum_truesize - gso_skb->truesize; + /* In some pathological cases, delta can be negative. + * We need to either use refcount_add() or refcount_sub_and_test() + */ + if (likely(delta >= 0)) + refcount_add(delta, &skb->sk->sk_wmem_alloc); + else + WARN_ON_ONCE(refcount_sub_and_test(-delta, &skb->sk->sk_wmem_alloc)); } delta = htonl(oldlen + (skb_tail_pointer(skb) - |