Merge branch 'master' into for-linus

Conflicts:
	block/Kconfig

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index fcd397a762ff..c5812bbc2cc9 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -340,8 +340,12 @@ int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
 		rc = sk_backlog_rcv(sk, skb);
 
 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
-	} else
-		sk_add_backlog(sk, skb);
+	} else if (sk_add_backlog(sk, skb)) {
+		bh_unlock_sock(sk);
+		atomic_inc(&sk->sk_drops);
+		goto discard_and_relse;
+	}
+
 	bh_unlock_sock(sk);
 out:
 	sock_put(sk);
@@ -1139,6 +1143,7 @@ struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
 		sock_lock_init(newsk);
 		bh_lock_sock(newsk);
 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
+		newsk->sk_backlog.len = 0;
 
 		atomic_set(&newsk->sk_rmem_alloc, 0);
 		/*
@@ -1542,6 +1547,12 @@ static void __release_sock(struct sock *sk)
 
 		bh_lock_sock(sk);
 	} while ((skb = sk->sk_backlog.head) != NULL);
+
+	/*
+	 * Doing the zeroing here guarantee we can not loop forever
+	 * while a wild producer attempts to flood us.
+	 */
+	sk->sk_backlog.len = 0;
 }
 
 /**
@@ -1874,6 +1885,7 @@ void sock_init_data(struct socket *sock, struct sock *sk)
 	sk->sk_allocation	=	GFP_KERNEL;
 	sk->sk_rcvbuf		=	sysctl_rmem_default;
 	sk->sk_sndbuf		=	sysctl_wmem_default;
+	sk->sk_backlog.limit	=	sk->sk_rcvbuf << 1;
 	sk->sk_state		=	TCP_CLOSE;
 	sk_set_socket(sk, sock);
 
@@ -2276,7 +2288,8 @@ out_free_request_sock_slab:
 		prot->rsk_prot->slab = NULL;
 	}
 out_free_request_sock_slab_name:
-	kfree(prot->rsk_prot->slab_name);
+	if (prot->rsk_prot)
+		kfree(prot->rsk_prot->slab_name);
 out_free_sock_slab:
 	kmem_cache_destroy(prot->slab);
 	prot->slab = NULL;