vxlan: Fix GRO cells race condition between receive and link delete

If we receive a packet while deleting a VXLAN device, there's a chance
vxlan_rcv() is called at the same time as vxlan_dellink(). This is fine,
except that vxlan_dellink() should never ever touch stuff that's still in
use, such as the GRO cells list.

Otherwise, vxlan_rcv() crashes while queueing packets via
gro_cells_receive().

Move the gro_cells_destroy() to vxlan_uninit(), which runs after the RCU
grace period is elapsed and nothing needs the gro_cells anymore.

This is now done in the same way as commit 8e816df879 ("geneve: Use GRO
cells infrastructure.") originally implemented for GENEVE.

Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: 58ce31cca1 ("vxlan: GRO support at tunnel layer")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Stefano Brivio 2019-03-08 16:40:57 +01:00 committed by David S. Miller
parent 930c9f9125
commit ad6c9986bc
1 changed files with 2 additions and 1 deletions

View File

@ -2767,6 +2767,8 @@ static void vxlan_uninit(struct net_device *dev)
{
struct vxlan_dev *vxlan = netdev_priv(dev);
gro_cells_destroy(&vxlan->gro_cells);
vxlan_fdb_delete_default(vxlan, vxlan->cfg.vni);
free_percpu(dev->tstats);
@ -3942,7 +3944,6 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head)
vxlan_flush(vxlan, true);
gro_cells_destroy(&vxlan->gro_cells);
list_del(&vxlan->next);
unregister_netdevice_queue(dev, head);
}