Messages in this thread Patch in this message | | | Date | Thu, 01 Apr 2010 15:30:52 +0800 | From | Cong Wang <> | Subject | [Patch V3] bonding: fix potential deadlock in bond_uninit() |
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Eric W. Biederman wrote: > Amerigo Wang <amwang@redhat.com> writes: > >> bond_uninit() is invoked with rtnl_lock held, when it does destroy_workqueue() >> which will potentially flush all works in this workqueue, if we hold rtnl_lock >> again in the work function, it will deadlock. >> >> So move destroy_workqueue() to destructor where rtnl_lock is not held any more, >> suggested by Eric. > > The error handling on creating a bond device needs to be updated as well. >
Done.
V3: fix error handling path of bond_create()
bond_uninit() is invoked with rtnl_lock held, when it does destroy_workqueue() which will potentially flush all works in this workqueue, if we hold rtnl_lock again in the work function, it will deadlock.
So move destroy_workqueue() to destructor where rtnl_lock is not held any more, suggested by Eric.
Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Jay Vosburgh <fubar@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Stephen Hemminger <shemminger@vyatta.com> Cc: Jiri Pirko <jpirko@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>
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diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 5b92fbf..61f8c63 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -4450,6 +4450,14 @@ static const struct net_device_ops bond_netdev_ops = { .ndo_vlan_rx_kill_vid = bond_vlan_rx_kill_vid, }; +static void bond_destructor(struct net_device *bond_dev) +{ + struct bonding *bond = netdev_priv(bond_dev); + if (bond->wq) + destroy_workqueue(bond->wq); + free_netdev(bond_dev); +} + static void bond_setup(struct net_device *bond_dev) { struct bonding *bond = netdev_priv(bond_dev); @@ -4470,7 +4478,7 @@ static void bond_setup(struct net_device *bond_dev) bond_dev->ethtool_ops = &bond_ethtool_ops; bond_set_mode_ops(bond, bond->params.mode); - bond_dev->destructor = free_netdev; + bond_dev->destructor = bond_destructor; /* Initialize the device options */ bond_dev->tx_queue_len = 0; @@ -4542,9 +4550,6 @@ static void bond_uninit(struct net_device *bond_dev) bond_remove_proc_entry(bond); - if (bond->wq) - destroy_workqueue(bond->wq); - netif_addr_lock_bh(bond_dev); bond_mc_list_destroy(bond); netif_addr_unlock_bh(bond_dev); @@ -4956,8 +4961,8 @@ int bond_create(struct net *net, const char *name) bond_setup); if (!bond_dev) { pr_err("%s: eek! can't alloc netdev!\n", name); - res = -ENOMEM; - goto out; + rtnl_unlock(); + return -ENOMEM; } dev_net_set(bond_dev, net); @@ -4966,19 +4971,16 @@ int bond_create(struct net *net, const char *name) if (!name) { res = dev_alloc_name(bond_dev, "bond%d"); if (res < 0) - goto out_netdev; + goto out; } res = register_netdevice(bond_dev); - if (res < 0) - goto out_netdev; out: rtnl_unlock(); + if (res < 0) + bond_destructor(bond_dev); return res; -out_netdev: - free_netdev(bond_dev); - goto out; } static int __net_init bond_net_init(struct net *net) | |