From 3006bc38895895f1a0352c2e17e1a503f35f7e2f Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 18 Nov 2010 09:30:42 -0800
Subject: [PATCH] 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>
---
drivers/net/bonding/bond_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index bdb68a600382..71a169740d05 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -878,8 +878,10 @@ static void __bond_resend_igmp_join_requests(struct net_device *dev)
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();
--
2.34.1