ipv4: Don't update the pmtu on mtu locked routes
Routes with locked mtu should not use learned pmtu informations,
so do not update the pmtu on these routes.
Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 6e4a89c..259cbee 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -912,6 +912,9 @@
struct dst_entry *dst = &rt->dst;
struct fib_result res;
+ if (dst_metric_locked(dst, RTAX_MTU))
+ return;
+
if (dst->dev->mtu < mtu)
return;