ipsec: Fix xfrm_state_walk race

As discovered by Timo Teräs, the currently xfrm_state_walk scheme
is racy because if a second dump finishes before the first, we
may free xfrm states that the first dump would walk over later.

This patch fixes this by storing the dumps in a list in order
to calculate the correct completion counter which cures this
problem.

I've expanded netlink_cb in order to accomodate the extra state
related to this.  It shouldn't be a big deal since netlink_cb
is kmalloced for each dump and we're just increasing it by 4 or
8 bytes.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 9ff1b54908f3..cbba7760545b 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -220,7 +220,7 @@ struct netlink_callback
         int             (*dump)(struct sk_buff * skb, struct netlink_callback *cb);
         int             (*done)(struct netlink_callback *cb);
         int             family;
-        long            args[6];
+        long            args[7];
 };
 
 struct netlink_notify