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 <mousuanm...@huawei.com>
Suggested-by: Eric Dumazet <eric.duma...@gmail.com>
Reviewed-by: Stefano Brivio <sbri...@redhat.com>
Reviewed-by: Zhiqiang Liu <liuzhiqian...@huawei.com>
---
V1->V3:
- update the commit message suggeted by Eric Dumazet
- update Fixes: tag
drivers/net/vxlan.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
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)
--
1.7.12.4
