Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit af2ac7bf authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Greg Kroah-Hartman
Browse files

Staging: batman-adv: Introduce if_list_lock to protect if_list 



The update critical sections of if_list must be protected by a locking
primitive other than RCU. The iterator must also be protected by the
chosen locking mechanism.

The rtnl_lock in hardif_remove_interfaces must also be moved outside the
iterator primitive to ensure that we don't deadlock the kernel due to
differently nested locks in hardif_remove_interfaces and hard_if_event.

Signed-off-by: default avatarSven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 67c3b705

drivers/staging/batman-adv/hard-interface.c

+15 −2
Original line number Diff line number Diff line
@@ -33,6 +33,9 @@ 


#define MIN(x, y) ((x) < (y) ? (x) : (y))



/* protect update critical side of if_list - but not the content */

static DEFINE_SPINLOCK(if_list_lock);



struct batman_if *get_batman_if_by_netdev(struct net_device *net_dev)

{

	struct batman_if *batman_if;
@@ -400,7 +403,11 @@ static struct batman_if *hardif_add_interface(struct net_device *net_dev) 
	INIT_LIST_HEAD(&batman_if->list);



	check_known_mac_addr(batman_if->net_dev->dev_addr);



	spin_lock(&if_list_lock);

	list_add_tail_rcu(&batman_if->list, &if_list);

	spin_unlock(&if_list_lock);



	return batman_if;



free_if:
@@ -428,6 +435,8 @@ static void hardif_remove_interface(struct batman_if *batman_if) 
		return;



	batman_if->if_status = IF_TO_BE_REMOVED;



	/* caller must take if_list_lock */

	list_del_rcu(&batman_if->list);

	sysfs_del_hardif(&batman_if->hardif_obj);

	dev_put(batman_if->net_dev);
@@ -438,11 +447,13 @@ void hardif_remove_interfaces(void) 
{

	struct batman_if *batman_if, *batman_if_tmp;



	list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {

	rtnl_lock();

	spin_lock(&if_list_lock);

	list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {

		hardif_remove_interface(batman_if);

		rtnl_unlock();

	}

	spin_unlock(&if_list_lock);

	rtnl_unlock();

}



static int hard_if_event(struct notifier_block *this,
@@ -467,7 +478,9 @@ static int hard_if_event(struct notifier_block *this, 
		hardif_deactivate_interface(batman_if);

		break;

	case NETDEV_UNREGISTER:

		spin_lock(&if_list_lock);

		hardif_remove_interface(batman_if);

		spin_unlock(&if_list_lock);

		break;

	case NETDEV_CHANGEMTU:

		if (batman_if->soft_iface)