[TCP]: 'dst' can be NULL in tcp_rto_min()

Reported by Rick Jones.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 1ee7212..bbad2cd 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -560,7 +560,7 @@ static u32 tcp_rto_min(struct sock *sk)
        struct dst_entry *dst = __sk_dst_get(sk);
        u32 rto_min = TCP_RTO_MIN;
 
-       if (dst_metric_locked(dst, RTAX_RTO_MIN))
+       if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
                rto_min = dst->metrics[RTAX_RTO_MIN-1];
        return rto_min;
 }