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

Commit 86b66abc authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Greg Kroah-Hartman
Browse files

batman-adv: Request iflink once in batadv-on-batadv check 



commit 690bb6fb64f5dc7437317153902573ecad67593d upstream.

There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_is_on_batman_iface. And since some of the
.ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.

Fixes: b7eddd0b ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 34dc4a6a

net/batman-adv/hard-interface.c

+5 −4
Original line number Diff line number Diff line
@@ -162,22 +162,23 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev) 
	struct net *net = dev_net(net_dev);

	struct net_device *parent_dev;

	struct net *parent_net;

	int iflink;

	bool ret;



	/* check if this is a batman-adv mesh interface */

	if (batadv_softif_is_valid(net_dev))

		return true;



	iflink = dev_get_iflink(net_dev);



	/* no more parents..stop recursion */

	if (dev_get_iflink(net_dev) == 0 ||

	    dev_get_iflink(net_dev) == net_dev->ifindex)

	if (iflink == 0 || iflink == net_dev->ifindex)

		return false;



	parent_net = batadv_getlink_net(net_dev, net);



	/* recurse over the parent device */

	parent_dev = __dev_get_by_index((struct net *)parent_net,

					dev_get_iflink(net_dev));

	parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);

	/* if we got a NULL parent_dev there is something broken.. */

	if (!parent_dev) {

		pr_err("Cannot find parent device\n");