Re: [PATCH v2] net: cgroup: fix access the unallocated memory in netprio cgroup

On Tue, 2012-07-10 at 13:05 +0200, Eric Dumazet wrote:

On Tue, 2012-07-10 at 18:44 +0800, Gao feng wrote:

quoted

there are some out of bound accesses in netprio cgroup.

quoted

-	update_netdev_tables();
+	ret = extend_netdev_table(dev, max_len);
+	if (ret < 0)
+		goto out_free_devname;
+
 	ret = 0;
 	rcu_read_lock();
 	map = rcu_dereference(dev->priomap);

Its unfortunately adding a bug.

extend_netdev_table() is protected by RTNL.

Please test your next patch using :

CONFIG_LOCKDEP=y
CONFIG_PROVE_RCU=y

Because rtnl_dereference() should shout if you dont hold RTNL