Message ID | 457d403f-c40d-8201-b10d-b4bf2f0b5be9@huawei.com |
---|---|
State | Accepted |
Delegated to: | David Miller |
Headers | show |
Series | [net,v3] vxlan: Don't call gro_cells_destroy() before device is unregistered | expand |
From: Zhiqiang Liu <liuzhiqiang26@huawei.com> Date: Sat, 16 Mar 2019 17:02:54 +0800 > Commit ad6c9986bcb62 ("vxlan: Fix GRO cells race condition between > receive and link delete") fixed a race condition for the typical case a vxlan > device is dismantled from the current netns. But if a netns is dismantled, > vxlan_destroy_tunnels() is called to schedule a unregister_netdevice_queue() > of all the vxlan tunnels that are related to this netns. > > In vxlan_destroy_tunnels(), gro_cells_destroy() is called and finished before > unregister_netdevice_queue(). This means that the gro_cells_destroy() call is > done too soon, for the same reasons explained in above commit. > > So we need to fully respect the RCU rules, and thus must remove the > gro_cells_destroy() call or risk use after-free. > > Fixes: 58ce31cca1ff ("vxlan: GRO support at tunnel layer") > Signed-off-by: Suanming.Mou <mousuanming@huawei.com> > Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> > Reviewed-by: Stefano Brivio <sbrivio@redhat.com> > Reviewed-by: Zhiqiang Liu <liuzhiqiang26@huawei.com> > --- > V1->V3: > - update the commit message suggeted by Eric Dumazet > - update Fixes: tag Applied and queued up for -stable, thanks.
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 077f1b9f2761..d76dfed8d9bb 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -4335,10 +4335,8 @@ static void vxlan_destroy_tunnels(struct net *net, struct list_head *head) /* If vxlan->dev is in the same netns, it has already been added * to the list by the previous loop. */ - if (!net_eq(dev_net(vxlan->dev), net)) { - gro_cells_destroy(&vxlan->gro_cells); + if (!net_eq(dev_net(vxlan->dev), net)) unregister_netdevice_queue(vxlan->dev, head); - } } for (h = 0; h < PORT_HASH_SIZE; ++h)