net: Handle NETREG_UNINITIALIZED devices correctly
Fix two problems:
1. If unregister_netdevice_many() is called with both registered
and unregistered devices, rollback_registered_many() bails out
when it reaches the first unregistered device. The processing
of the prior registered devices is unfinished, and the
remaining devices are skipped, and possible registered netdev's
are leaked/unregistered.
2. System hangs or panics depending on how the devices are passed,
since when netdev_run_todo() runs, some devices were not fully
processed.
Tested by passing intermingled unregistered and registered vlan
devices to unregister_netdevice_many() as follows:
1. dev, fake_dev1, fake_dev2: hangs in run_todo
("unregister_netdevice: waiting for eth1.100 to become
free. Usage count = 1")
2. fake_dev1, dev, fake_dev2: failure during de-registration
and next registration, followed by a vlan driver Oops
during subsequent registration.
Confirmed that the patch fixes both cases.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index c36a17a..6fe7d73 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4771,21 +4771,23 @@
static void rollback_registered_many(struct list_head *head)
{
- struct net_device *dev;
+ struct net_device *dev, *tmp;
BUG_ON(dev_boot_phase);
ASSERT_RTNL();
- list_for_each_entry(dev, head, unreg_list) {
+ list_for_each_entry_safe(dev, tmp, head, unreg_list) {
/* Some devices call without registering
- * for initialization unwind.
+ * for initialization unwind. Remove those
+ * devices and proceed with the remaining.
*/
if (dev->reg_state == NETREG_UNINITIALIZED) {
pr_debug("unregister_netdevice: device %s/%p never "
"was registered\n", dev->name, dev);
WARN_ON(1);
- return;
+ list_del(&dev->unreg_list);
+ continue;
}
BUG_ON(dev->reg_state != NETREG_REGISTERED);