From: Hangbin Liu Date: Fri, 27 Apr 2018 12:59:24 +0000 (+0800) Subject: bridge: check iface upper dev when setting master via ioctl X-Git-Tag: v3.18.110~44 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=32037ab332f95a914923d7017377815e5d1f6433;p=thirdparty%2Fkernel%2Fstable.git bridge: check iface upper dev when setting master via ioctl [ Upstream commit e8238fc2bd7b4c3c7554fa2df067e796610212fc ] When we set a bond slave's master to bridge via ioctl, we only check the IFF_BRIDGE_PORT flag. Although we will find the slave's real master at netdev_master_upper_dev_link() later, it already does some settings and allocates some resources. It would be better to return as early as possible. v1 -> v2: use netdev_master_upper_dev_get() instead of netdev_has_any_upper_dev() to check if we have a master, because not all upper devs are masters, e.g. vlan device. Reported-by: syzbot+de73361ee4971b6e6f75@syzkaller.appspotmail.com Signed-off-by: Hangbin Liu Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index ed307db7a12b6..ef88729ad3d75 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -445,8 +445,8 @@ int br_add_if(struct net_bridge *br, struct net_device *dev) if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) return -ELOOP; - /* Device is already being bridged */ - if (br_port_exists(dev)) + /* Device has master upper dev */ + if (netdev_master_upper_dev_get(dev)) return -EBUSY; /* No bridging devices that dislike that (e.g. wireless) */