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>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index bdb68a6..71a1697 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -878,8 +878,10 @@
rcu_read_lock();
in_dev = __in_dev_get_rcu(dev);
if (in_dev) {
+ read_lock(&in_dev->mc_list_lock);
for (im = in_dev->mc_list; im; im = im->next)
ip_mc_rejoin_group(im);
+ read_unlock(&in_dev->mc_list_lock);
}
rcu_read_unlock();