ipv6: Fix traffic triggered IPsec connections.

A recent patch removed the dst_free() on the allocated dst_entry in ipv6_blackhole_route(). The dst_free() marked the dst_entry as dead and added it to the gc list. I.e. it was setup for a one time usage. As a result we may now have a blackhole route cached at a socket on some IPsec scenarios. This makes the connection unusable.

Fix this by marking the dst_entry directly at allocation time as 'dead', so it is used only once.

---
 net/ipv6/route.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 26cc9f4..a96d5b3 100644
@@ -1325,7 +1325,7 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
 	struct dst_entry *new = NULL;
 
 	rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
-		       DST_OBSOLETE_NONE, 0);
+		       DST_OBSOLETE_DEAD, 0);
 	if (rt) {
 		rt6_info_init(rt);
 

2.7.4

From: Steffen Klassert <[email protected]>
Date: Mon, 9 Oct 2017 08:39:43 +0200

Applied and queued up for -stable, thanks.