Commit be94cfdb authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

dev: Hold rtnl_net_lock() for dev_ifsioc(). 



Basically, dev_ifsioc() operates on the passed single netns (except
for netdev notifier chains with lower/upper devices for which we will
need more changes).

Let's hold rtnl_net_lock() for dev_ifsioc().

Now that NETDEV_CHANGENAME is always triggered under rtnl_net_lock()
of the device's netns. (do_setlink() and dev_ifsioc())

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250115095545.52709-4-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 2f1bb1e2

net/core/dev.c

+2 −5
Original line number Diff line number Diff line
@@ -1348,16 +1348,13 @@ static int dev_get_valid_name(struct net *net, struct net_device *dev, 
 */

int dev_change_name(struct net_device *dev, const char *newname)

{

	struct net *net = dev_net(dev);

	unsigned char old_assign_type;

	char oldname[IFNAMSIZ];

	int err = 0;

	int ret;

	struct net *net;



	ASSERT_RTNL();

	BUG_ON(!dev_net(dev));



	net = dev_net(dev);

	ASSERT_RTNL_NET(net);



	if (!strncmp(newname, dev->name, IFNAMSIZ))

		return 0;

net/core/dev_ioctl.c

+17 −9
Original line number Diff line number Diff line
@@ -543,7 +543,7 @@ static int dev_siocwandev(struct net_device *dev, struct if_settings *ifs) 
}



/*

 *	Perform the SIOCxIFxxx calls, inside rtnl_lock()

 *	Perform the SIOCxIFxxx calls, inside rtnl_net_lock()

 */

static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data,

		      unsigned int cmd)
@@ -620,11 +620,14 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, void __user *data, 
			return -ENODEV;

		if (!netif_is_bridge_master(dev))

			return -EOPNOTSUPP;



		netdev_hold(dev, &dev_tracker, GFP_KERNEL);

		rtnl_unlock();

		rtnl_net_unlock(net);



		err = br_ioctl_call(net, netdev_priv(dev), cmd, ifr, NULL);



		netdev_put(dev, &dev_tracker);

		rtnl_lock();

		rtnl_net_lock(net);

		return err;



	case SIOCDEVPRIVATE ... SIOCDEVPRIVATE + 15:
@@ -770,9 +773,11 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, 
		dev_load(net, ifr->ifr_name);

		if (!ns_capable(net->user_ns, CAP_NET_ADMIN))

			return -EPERM;

		rtnl_lock();



		rtnl_net_lock(net);

		ret = dev_ifsioc(net, ifr, data, cmd);

		rtnl_unlock();

		rtnl_net_unlock(net);



		if (colon)

			*colon = ':';

		return ret;
@@ -816,9 +821,11 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, 
	case SIOCBONDSLAVEINFOQUERY:

	case SIOCBONDINFOQUERY:

		dev_load(net, ifr->ifr_name);

		rtnl_lock();



		rtnl_net_lock(net);

		ret = dev_ifsioc(net, ifr, data, cmd);

		rtnl_unlock();

		rtnl_net_unlock(net);



		if (need_copyout)

			*need_copyout = false;

		return ret;
@@ -841,9 +848,10 @@ int dev_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr, 
		    (cmd >= SIOCDEVPRIVATE &&

		     cmd <= SIOCDEVPRIVATE + 15)) {

			dev_load(net, ifr->ifr_name);

			rtnl_lock();



			rtnl_net_lock(net);

			ret = dev_ifsioc(net, ifr, data, cmd);

			rtnl_unlock();

			rtnl_net_unlock(net);

			return ret;

		}

		return -ENOTTY;

net/core/rtnl_net_debug.c

+3 −12
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ static int rtnl_net_debug_event(struct notifier_block *nb, 
	case NETDEV_CHANGEADDR:

	case NETDEV_PRE_CHANGEADDR:

	case NETDEV_GOING_DOWN:

	case NETDEV_CHANGENAME:

	case NETDEV_FEAT_CHANGE:

	case NETDEV_BONDING_FAILOVER:

	case NETDEV_PRE_UP:
@@ -60,18 +59,10 @@ static int rtnl_net_debug_event(struct notifier_block *nb, 
		ASSERT_RTNL();

		break;



	/* Once an event fully supports RTNL_NET, move it here

	 * and remove "if (0)" below.

	 *

	 * case NETDEV_XXX:

	 *	ASSERT_RTNL_NET(net);

	 *	break;

	 */

	}



	/* Just to avoid unused-variable error for dev and net. */

	if (0)

	case NETDEV_CHANGENAME:

		ASSERT_RTNL_NET(net);

		break;

	}



	return NOTIFY_DONE;

}