netns: foreach_netdev_safe is insufficient in default_device_exit
During network namespace teardown we either move or delete
all of the network devices associated with a network namespace.
In the case of veth devices deleting one will also delete it's
pair device. If both devices are in the same network namespace
then for_each_netdev_safe is insufficient as next may point
to the second veth device we have deleted.
To avoid problems I do what we do in __rtnl_kill_links and
restart the scan of the device list, after we have deleted
a device.
Currently dev_change_netnamespace does not appear to suffer from
this problem, but wireless devices are also paired and likely
should be moved between network namespaces together. So I have
errored on the side of caution and restart the scan of the network
devices in that case as well.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 4464240..09c66a4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5066,13 +5066,14 @@
static void __net_exit default_device_exit(struct net *net)
{
- struct net_device *dev, *next;
+ struct net_device *dev;
/*
* Push all migratable of the network devices back to the
* initial network namespace
*/
rtnl_lock();
- for_each_netdev_safe(net, dev, next) {
+restart:
+ for_each_netdev(net, dev) {
int err;
char fb_name[IFNAMSIZ];
@@ -5083,7 +5084,7 @@
/* Delete virtual devices */
if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink) {
dev->rtnl_link_ops->dellink(dev);
- continue;
+ goto restart;
}
/* Push remaing network devices to init_net */
@@ -5094,6 +5095,7 @@
__func__, dev->name, err);
BUG();
}
+ goto restart;
}
rtnl_unlock();
}