ipv6: fix inet6_csk_update_pmtu() return value

In case of error, inet6_csk_update_pmtu() should consistently
return NULL.

Bug added in commit 35ad9b9cf7d8a
(ipv6: Add helper inet6_csk_update_pmtu().)

Reported-by: Lluís Batlle i Rossell <viric@viric.name>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/ipv6/inet6_connection_sock.c b/net/ipv6/inet6_connection_sock.c
index c4f934176cab..30647857a375 100644
--- a/net/ipv6/inet6_connection_sock.c
+++ b/net/ipv6/inet6_connection_sock.c
@@ -252,6 +252,7 @@ struct dst_entry *inet6_csk_update_pmtu(struct sock *sk, u32 mtu)
                 return NULL;
         dst->ops->update_pmtu(dst, sk, NULL, mtu);
 
-        return inet6_csk_route_socket(sk, &fl6);
+        dst = inet6_csk_route_socket(sk, &fl6);
+        return IS_ERR(dst) ? NULL : dst;
 }
 EXPORT_SYMBOL_GPL(inet6_csk_update_pmtu);