| From foo@baz Thu Mar 28 21:57:57 CET 2019 |
| From: Zhiqiang Liu <liuzhiqiang26@huawei.com> |
| Date: Sat, 16 Mar 2019 17:02:54 +0800 |
| Subject: vxlan: Don't call gro_cells_destroy() before device is unregistered |
| |
| From: Zhiqiang Liu <liuzhiqiang26@huawei.com> |
| |
| [ Upstream commit cc4807bb609230d8959fd732b0bf3bd4c2de8eac ] |
| |
| 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> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/vxlan.c | 4 +--- |
| 1 file changed, 1 insertion(+), 3 deletions(-) |
| |
| --- a/drivers/net/vxlan.c |
| +++ b/drivers/net/vxlan.c |
| @@ -3793,10 +3793,8 @@ static void __net_exit vxlan_exit_net(st |
| /* 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, &list); |
| - } |
| } |
| |
| unregister_netdevice_many(&list); |