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ipv4: Fix traffic triggered IPsec connections.

PATCH In review Steffen Klassert 2 participants 2 messages Oct 9, 2017

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Networking Network drivers IPv4/IPv6
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Steffen Klassert

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#0 lore raw

PATCH 1/1 ipv4: Fix traffic triggered IPsec connections.

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 <[email protected]>
Signed-off-by Steffen Klassert <[email protected]>
---
 net/ipv4/route.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
net/ipv4/route.c +1 -1
index ac6fde5..3d9f1c2 100644
@@ -2513,7 +2513,7 @@ 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;
Signature · 1 line
2.7.4
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#1 lore raw

From: Steffen Klassert <[email protected]>
Date: Mon, 9 Oct 2017 08:43:55 +0200

Quoted 7 lines

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.

Quoted 6 lines

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 <[email protected]>
Signed-off-by Steffen Klassert <[email protected]>

Applied and queued up for -stable.