From: Sven Eckelmann Date: Sun, 27 Feb 2022 23:01:24 +0000 (+0100) Subject: batman-adv: Request iflink once in batadv_get_real_netdevice X-Git-Tag: accepted/tizen/unified/20230118.172025~1867 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=94355d99ad70706437824db608424d46857b35c7;p=platform%2Fkernel%2Flinux-rpi.git batman-adv: Request iflink once in batadv_get_real_netdevice commit 6116ba09423f7d140f0460be6a1644dceaad00da upstream. There is no need to call dev_get_iflink multiple times for the same net_device in batadv_get_real_netdevice. 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: 5ed4a460a1d3 ("batman-adv: additional checks for virtual interfaces on top of WiFi") Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 35aa112..e2760cf 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -215,14 +215,16 @@ static struct net_device *batadv_get_real_netdevice(struct net_device *netdev) struct net_device *real_netdev = NULL; struct net *real_net; struct net *net; - int ifindex; + int iflink; ASSERT_RTNL(); if (!netdev) return NULL; - if (netdev->ifindex == dev_get_iflink(netdev)) { + iflink = dev_get_iflink(netdev); + + if (netdev->ifindex == iflink) { dev_hold(netdev); return netdev; } @@ -232,9 +234,8 @@ static struct net_device *batadv_get_real_netdevice(struct net_device *netdev) goto out; net = dev_net(hard_iface->soft_iface); - ifindex = dev_get_iflink(netdev); real_net = batadv_getlink_net(netdev, net); - real_netdev = dev_get_by_index(real_net, ifindex); + real_netdev = dev_get_by_index(real_net, iflink); out: batadv_hardif_put(hard_iface);