Commit 748e2d93 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: reinstate rtnl in call_netdevice_notifiers() 



Eric Biederman pointed out that not holding RTNL while calling
call_netdevice_notifiers() was racy.

This patch is a direct transcription his feedback
against commit 0115e8e3 (net: remove delay at device dismantle)

Thanks Eric !

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0fa7fa98

net/core/dev.c

+7 −2
Original line number Original line Diff line number Diff line
@@ -1466,7 +1466,6 @@ EXPORT_SYMBOL(unregister_netdevice_notifier); 




int call_netdevice_notifiers(unsigned long val, struct net_device *dev)

int call_netdevice_notifiers(unsigned long val, struct net_device *dev)

{

{

	if (val != NETDEV_UNREGISTER_FINAL)

	ASSERT_RTNL();

	ASSERT_RTNL();

	return raw_notifier_call_chain(&netdev_chain, val, dev);

	return raw_notifier_call_chain(&netdev_chain, val, dev);

}

}
@@ -5782,7 +5781,11 @@ static void netdev_wait_allrefs(struct net_device *dev) 




			/* Rebroadcast unregister notification */

			/* Rebroadcast unregister notification */

			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);

			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);



			__rtnl_unlock();

			rcu_barrier();

			rcu_barrier();

			rtnl_lock();



			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);

			call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);

			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,

			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,

				     &dev->state)) {

				     &dev->state)) {
@@ -5855,7 +5858,9 @@ void netdev_run_todo(void) 
			= list_first_entry(&list, struct net_device, todo_list);

			= list_first_entry(&list, struct net_device, todo_list);

		list_del(&dev->todo_list);

		list_del(&dev->todo_list);





		rtnl_lock();

		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);

		call_netdevice_notifiers(NETDEV_UNREGISTER_FINAL, dev);

		__rtnl_unlock();





		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {

		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {

			pr_err("network todo '%s' but state %d\n",

			pr_err("network todo '%s' but state %d\n",

net/core/fib_rules.c

+1 −2
Original line number Original line Diff line number Diff line
@@ -711,16 +711,15 @@ static int fib_rules_event(struct notifier_block *this, unsigned long event, 
	struct net *net = dev_net(dev);

	struct net *net = dev_net(dev);

	struct fib_rules_ops *ops;

	struct fib_rules_ops *ops;





	ASSERT_RTNL();





	switch (event) {

	switch (event) {

	case NETDEV_REGISTER:

	case NETDEV_REGISTER:

		ASSERT_RTNL();

		list_for_each_entry(ops, &net->rules_ops, list)

		list_for_each_entry(ops, &net->rules_ops, list)

			attach_rules(&ops->rules_list, dev);

			attach_rules(&ops->rules_list, dev);

		break;

		break;





	case NETDEV_UNREGISTER:

	case NETDEV_UNREGISTER:

		ASSERT_RTNL();

		list_for_each_entry(ops, &net->rules_ops, list)

		list_for_each_entry(ops, &net->rules_ops, list)

			detach_rules(&ops->rules_list, dev);

			detach_rules(&ops->rules_list, dev);

		break;

		break;

net/ipv4/devinet.c

+1 −5
Original line number Original line Diff line number Diff line
@@ -1147,12 +1147,8 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, 
			 void *ptr)

			 void *ptr)

{

{

	struct net_device *dev = ptr;

	struct net_device *dev = ptr;

	struct in_device *in_dev;

	struct in_device *in_dev = __in_dev_get_rtnl(dev);



	if (event == NETDEV_UNREGISTER_FINAL)

		goto out;





	in_dev = __in_dev_get_rtnl(dev);

	ASSERT_RTNL();

	ASSERT_RTNL();





	if (!in_dev) {

	if (!in_dev) {

net/ipv4/fib_frontend.c

+2 −5
Original line number Original line Diff line number Diff line
@@ -1050,9 +1050,6 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo 
		return NOTIFY_DONE;

		return NOTIFY_DONE;

	}

	}





	if (event == NETDEV_UNREGISTER_FINAL)

		return NOTIFY_DONE;



	in_dev = __in_dev_get_rtnl(dev);

	in_dev = __in_dev_get_rtnl(dev);





	switch (event) {

	switch (event) {
@@ -1064,14 +1061,14 @@ static int fib_netdev_event(struct notifier_block *this, unsigned long event, vo 
		fib_sync_up(dev);

		fib_sync_up(dev);

#endif

#endif

		atomic_inc(&net->ipv4.dev_addr_genid);

		atomic_inc(&net->ipv4.dev_addr_genid);

		rt_cache_flush(dev_net(dev), -1);

		rt_cache_flush(net, -1);

		break;

		break;

	case NETDEV_DOWN:

	case NETDEV_DOWN:

		fib_disable_ip(dev, 0, 0);

		fib_disable_ip(dev, 0, 0);

		break;

		break;

	case NETDEV_CHANGEMTU:

	case NETDEV_CHANGEMTU:

	case NETDEV_CHANGE:

	case NETDEV_CHANGE:

		rt_cache_flush(dev_net(dev), 0);

		rt_cache_flush(net, 0);

		break;

		break;

	}

	}

	return NOTIFY_DONE;

	return NOTIFY_DONE;

net/ipv6/addrconf.c

+1 −5
Original line number Original line Diff line number Diff line
@@ -2566,14 +2566,10 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, 
			   void *data)

			   void *data)

{

{

	struct net_device *dev = (struct net_device *) data;

	struct net_device *dev = (struct net_device *) data;

	struct inet6_dev *idev;

	struct inet6_dev *idev = __in6_dev_get(dev);

	int run_pending = 0;

	int run_pending = 0;

	int err;

	int err;





	if (event == NETDEV_UNREGISTER_FINAL)

		return NOTIFY_DONE;



	idev = __in6_dev_get(dev);

	switch (event) {

	switch (event) {

	case NETDEV_REGISTER:

	case NETDEV_REGISTER:

		if (!idev && dev->mtu >= IPV6_MIN_MTU) {

		if (!idev && dev->mtu >= IPV6_MIN_MTU) {

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