ipv4: Fix traffic triggered IPsec connections.

[ Upstream commit 6c0e7284d89995877740d8a26c3e99a937312a3c ]

A recent patch removed the dst_free() on the allocated
dst_entry in ipv4_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.

Fixes: b838d5e1c5b6 ("ipv4: mark DST_NOGC and remove the operation of dst_free()")
Reported-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c5aa25be71085269b6485b867bdf40df27fb9fff..72afa4cfb022511f4d84a8c1471224eb4c866d03 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2507,7 +2507,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
        struct rtable *ort = (struct rtable *) dst_orig;
        struct rtable *rt;
 
-       rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
+       rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_DEAD, 0);
        if (rt) {
                struct dst_entry *new = &rt->dst;