net: openvswitch: fixes potential deadlock in dp cleanup code

The previous patch introduced a deadlock, this patch fixes it by making
sure the work is canceled without holding the global ovs lock. This is
done by moving the reorder processing one layer up to the netns level.

Fixes: eac87c413b ("net: openvswitch: reorder masks array based on usage")
Reported-by: syzbot+2c4ff3614695f75ce26c@syzkaller.appspotmail.com
Reported-by: syzbot+bad6507e5db05017b008@syzkaller.appspotmail.com
Reviewed-by: Paolo <pabeni@redhat.com>
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eelco Chaudron
2020-07-24 10:20:59 +02:00
committed by David S. Miller
parent dfd3d5266d
commit a65878d6f0
2 changed files with 13 additions and 14 deletions

View File

@@ -1655,7 +1655,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
goto err_destroy_reply;
ovs_dp_set_net(dp, sock_net(skb->sk));
INIT_DELAYED_WORK(&dp->masks_rebalance, ovs_dp_masks_rebalance);
/* Allocate table. */
err = ovs_flow_tbl_init(&dp->table);
@@ -1715,9 +1714,6 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
ovs_net = net_generic(ovs_dp_get_net(dp), ovs_net_id);
list_add_tail_rcu(&dp->list_node, &ovs_net->dps);
schedule_delayed_work(&dp->masks_rebalance,
msecs_to_jiffies(DP_MASKS_REBALANCE_INTERVAL));
ovs_unlock();
ovs_notify(&dp_datapath_genl_family, reply, info);
@@ -1762,9 +1758,6 @@ static void __dp_destroy(struct datapath *dp)
/* RCU destroy the flow table */
call_rcu(&dp->rcu, destroy_dp_rcu);
/* Cancel remaining work. */
cancel_delayed_work_sync(&dp->masks_rebalance);
}
static int ovs_dp_cmd_del(struct sk_buff *skb, struct genl_info *info)
@@ -2349,14 +2342,18 @@ out:
static void ovs_dp_masks_rebalance(struct work_struct *work)
{
struct datapath *dp = container_of(work, struct datapath,
masks_rebalance.work);
struct ovs_net *ovs_net = container_of(work, struct ovs_net,
masks_rebalance.work);
struct datapath *dp;
ovs_lock();
ovs_flow_masks_rebalance(&dp->table);
list_for_each_entry(dp, &ovs_net->dps, list_node)
ovs_flow_masks_rebalance(&dp->table);
ovs_unlock();
schedule_delayed_work(&dp->masks_rebalance,
schedule_delayed_work(&ovs_net->masks_rebalance,
msecs_to_jiffies(DP_MASKS_REBALANCE_INTERVAL));
}
@@ -2454,6 +2451,9 @@ static int __net_init ovs_init_net(struct net *net)
INIT_LIST_HEAD(&ovs_net->dps);
INIT_WORK(&ovs_net->dp_notify_work, ovs_dp_notify_wq);
INIT_DELAYED_WORK(&ovs_net->masks_rebalance, ovs_dp_masks_rebalance);
schedule_delayed_work(&ovs_net->masks_rebalance,
msecs_to_jiffies(DP_MASKS_REBALANCE_INTERVAL));
return ovs_ct_init(net);
}
@@ -2508,6 +2508,7 @@ static void __net_exit ovs_exit_net(struct net *dnet)
ovs_unlock();
cancel_delayed_work_sync(&ovs_net->masks_rebalance);
cancel_work_sync(&ovs_net->dp_notify_work);
}