[SCTP]: Return socket errors only if the receive queue is empty.

This patch fixes an issue where it is possible to get valid data after
a ENOTCONN error. It returns socket errors only after data queued on
socket receive queue is consumed.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index abab81f3818f1a4c77742b315ad943853ad062ce..d890dfa8818fb27c592f950506e1ccd7144e55c7 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4743,11 +4743,6 @@ static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
        struct sk_buff *skb;
        long timeo;
 
-       /* Caller is allowed not to check sk->sk_err before calling.  */
-       error = sock_error(sk);
-       if (error)
-               goto no_packet;
-
        timeo = sock_rcvtimeo(sk, noblock);
 
        SCTP_DEBUG_PRINTK("Timeout: timeo: %ld, MAX: %ld.\n",
@@ -4774,6 +4769,11 @@ static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
                if (skb)
                        return skb;
 
+               /* Caller is allowed not to check sk->sk_err before calling. */
+               error = sock_error(sk);
+               if (error)
+                       goto no_packet;
+
                if (sk->sk_shutdown & RCV_SHUTDOWN)
                        break;