bonding: fix a race in IGMP handling

RCU conversion in IGMP code done in net-next-2.6 raised a race in
__bond_resend_igmp_join_requests().

It iterates in_dev->mc_list without appropriate protection (RTNL, or
read_lock on in_dev->mc_list_lock).

Another cpu might delete an entry while we use it and trigger a fault.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-11-18 09:30:42 -08:00 committed by David S. Miller
parent 28cb6ccd2c
commit 3006bc3889

View File

@ -878,8 +878,10 @@ static void __bond_resend_igmp_join_requests(struct net_device *dev)
rcu_read_lock(); rcu_read_lock();
in_dev = __in_dev_get_rcu(dev); in_dev = __in_dev_get_rcu(dev);
if (in_dev) { if (in_dev) {
read_lock(&in_dev->mc_list_lock);
for (im = in_dev->mc_list; im; im = im->next) for (im = in_dev->mc_list; im; im = im->next)
ip_mc_rejoin_group(im); ip_mc_rejoin_group(im);
read_unlock(&in_dev->mc_list_lock);
} }
rcu_read_unlock(); rcu_read_unlock();