From e93737b0f0159a61772894943199fd3b6f315641 Mon Sep 17 00:00:00 2001 From: Krishna Kumar Date: Tue, 8 Dec 2009 22:26:02 +0000 Subject: [PATCH] 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 Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index c36a17aafcf..6fe7d739e59 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4771,21 +4771,23 @@ static void net_set_todo(struct net_device *dev) 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);