1 files changed, 15 insertions, 2 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 6cb1676e409a..092b0551e77f 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -253,6 +253,8 @@ struct sock {
         struct {
                 struct sk_buff *head;
                 struct sk_buff *tail;
+                int len;
+                int limit;
         } sk_backlog;
         wait_queue_head_t       *sk_sleep;
         struct dst_entry        *sk_dst_cache;
@@ -589,8 +591,8 @@ static inline int sk_stream_memory_free(struct sock *sk)
         return sk->sk_wmem_queued < sk->sk_sndbuf;
 }
 
-/* The per-socket spinlock must be held here. */
-static inline void sk_add_backlog(struct sock *sk, struct sk_buff *skb)
+/* OOB backlog add */
+static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 {
         if (!sk->sk_backlog.tail) {
                 sk->sk_backlog.head = sk->sk_backlog.tail = skb;
@@ -601,6 +603,17 @@ static inline void sk_add_backlog(struct sock *sk, struct sk_buff *skb)
         skb->next = NULL;
 }
 
+/* The per-socket spinlock must be held here. */
+static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb)
+{
+        if (sk->sk_backlog.len >= max(sk->sk_backlog.limit, sk->sk_rcvbuf << 1))
+                return -ENOBUFS;
+
+        __sk_add_backlog(sk, skb);
+        sk->sk_backlog.len += skb->truesize;
+        return 0;
+}
+
 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 {
         return sk->sk_backlog_rcv(sk, skb);