4.20-stable review patch. If anyone has any objections, please let me know.
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From: Stefano Brivio sbrivio@redhat.com
[ 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 jishi@redhat.com Fixes: 58ce31cca1ff ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/vxlan.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -2529,6 +2529,8 @@ static void vxlan_uninit(struct net_devi { 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_dev
vxlan_flush(vxlan, true);
- gro_cells_destroy(&vxlan->gro_cells); list_del(&vxlan->next); unregister_netdevice_queue(dev, head); }