From: Stefano Brivio Date: Fri, 8 Mar 2019 15:40:57 +0000 (+0100) Subject: vxlan: Fix GRO cells race condition between receive and link delete X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=72ad13ea5a4f20f5fbc559f4991bd1e51a176a8c;p=linux vxlan: Fix GRO cells race condition between receive and link delete [ Upstream commit ad6c9986bcb627c7c22b8f9e9a934becc27df87c ] 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 8e816df87997 ("geneve: Use GRO cells infrastructure.") originally implemented for GENEVE. Reported-by: Jianlin Shi Fixes: 58ce31cca1ff ("vxlan: GRO support at tunnel layer") Signed-off-by: Stefano Brivio Reviewed-by: Sabrina Dubroca Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index 8f022964b2d1..0f4882cb6835 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -2529,6 +2529,8 @@ 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); @@ -3601,7 +3603,6 @@ 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); }