tcp/dccp: block BH for SYN processing

[karo-tx-linux.git] / net / ipv4 / tcp_input.c

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 2c0ff327b6dfe6919f22bf52687816e19c2c0444..39c393cc0fd3c17130cd5d8d8b37f31ad3aeafd9 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5886,9 +5886,15 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
                if (th->syn) {
                        if (th->fin)
                                goto discard;
-                       if (icsk->icsk_af_ops->conn_request(sk, skb) < 0)
-                               return 1;
+                       /* It is possible that we process SYN packets from backlog,
+                        * so we need to make sure to disable BH right there.
+                        */
+                       local_bh_disable();
+                       acceptable = icsk->icsk_af_ops->conn_request(sk, skb) >= 0;
+                       local_bh_enable();
 
+                       if (!acceptable)
+                               return 1;
                        consume_skb(skb);
                        return 0;
                }