ipvs: do not use dest after ip_vs_dest_put in LBLCR
authorJulian Anastasov <ja@ssi.bg>
Thu, 12 Sep 2013 08:21:09 +0000 (11:21 +0300)
committerSimon Horman <horms@verge.net.au>
Wed, 18 Sep 2013 19:39:39 +0000 (14:39 -0500)
commit742617b176909e586a4cf9b142c996c25986fce8
tree50889a950b87f84ec85e485d4d95409c9c356da7
parent2f3d771a35fee21a1f17364b46b3c8cc66dc6892
ipvs: do not use dest after ip_vs_dest_put in LBLCR

commit c5549571f975ab ("ipvs: convert lblcr scheduler to rcu")
allows RCU readers to use dest after calling ip_vs_dest_put().
In the corner case it can race with ip_vs_dest_trash_expire()
which can release the dest while it is being returned to the
RCU readers as scheduling result.

To fix the problem do not allow e->dest to be replaced and
defer the ip_vs_dest_put() call by using RCU callback. Now
e->dest does not need to be RCU pointer.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
net/netfilter/ipvs/ip_vs_lblcr.c