From c6761cf521f9bffbdcbb619dba665ebf3bcefb1e Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Wed, 30 Oct 2019 08:15:12 +0000 Subject: vxlan: fix unexpected failure of vxlan_changelink() After commit 0ce1822c2a08 ("vxlan: add adjacent link to limit depth level"), vxlan_changelink() could fail because of netdev_adjacent_change_prepare(). netdev_adjacent_change_prepare() returns -EEXIST when old lower device and new lower device are same. (old lower device is "dst->remote_dev" and new lower device is "lowerdev") So, before calling it, lowerdev should be NULL if these devices are same. Test command1: ip link add dummy0 type dummy ip link add vxlan0 type vxlan dev dummy0 dstport 4789 vni 1 ip link set vxlan0 type vxlan ttl 5 RTNETLINK answers: File exists Reported-by: Dan Carpenter Fixes: 0ce1822c2a08 ("vxlan: add adjacent link to limit depth level") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller --- drivers/net/vxlan.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'drivers/net/vxlan.c') diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index ac5c597aa703..8869154fad88 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -3967,6 +3967,9 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[], if (err) return err; + if (dst->remote_dev == lowerdev) + lowerdev = NULL; + err = netdev_adjacent_change_prepare(dst->remote_dev, lowerdev, dev, extack); if (err) @@ -4008,10 +4011,10 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[], mod_timer(&vxlan->age_timer, jiffies); netdev_adjacent_change_commit(dst->remote_dev, lowerdev, dev); - if (lowerdev && lowerdev != dst->remote_dev) + if (lowerdev && lowerdev != dst->remote_dev) { dst->remote_dev = lowerdev; - - netdev_update_lockdep_key(lowerdev); + netdev_update_lockdep_key(lowerdev); + } vxlan_config_apply(dev, &conf, lowerdev, vxlan->net, true); return 0; } -- cgit v1.2.3-59-g8ed1b