Commit b43faac6 authored Dec 13, 2011 by David S. Miller

ipv6: If neigh lookup fails during icmp6 dst allocation, propagate error.



Don't just succeed with a route that has a NULL neighbour attached.
This follows the behavior of addrconf_dst_alloc().

Allowing this kind of route to end up with a NULL neigh attached will
result in packet drops on output until the route is somehow
invalidated, since nothing will meanwhile try to lookup the neigh
again.

A statistic is bumped for the case where we see a neigh-less route on
output, but the resulting packet drop is otherwise silent in nature,
and frankly it's a hard error for this to happen and ipv6 should do
what ipv4 does which is say something in the kernel logs.

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

parent 5c3ddec7

net/ipv6/route.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -1089,8 +1089,10 @@ struct dst_entry icmp6_dst_alloc(struct net_device dev,
		neigh_hold(neigh);
		else {
		neigh = __neigh_lookup_errno(&nd_tbl, &fl6->daddr, dev);
		if (IS_ERR(neigh))
		neigh = NULL;
		if (IS_ERR(neigh)) {
		dst_free(&rt->dst);
		return ERR_CAST(neigh);
		}
		}

		rt->dst.flags \|= DST_HOST;

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