| Message ID | 20191030081512.25743-1-ap420073@gmail.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] vxlan: fix unexpected failure of vxlan_changelink() | expand |
From: Taehee Yoo <ap420073@gmail.com> Date: Wed, 30 Oct 2019 08:15:12 +0000 > 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 <dan.carpenter@oracle.com> > Fixes: 0ce1822c2a08 ("vxlan: add adjacent link to limit depth level") > Signed-off-by: Taehee Yoo <ap420073@gmail.com> Applied, thank you.
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index fcf028220bca..a01b8ddaa44a 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -3965,6 +3965,9 @@ 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) @@ -4006,10 +4009,10 @@ 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; }
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 <dan.carpenter@oracle.com> Fixes: 0ce1822c2a08 ("vxlan: add adjacent link to limit depth level") Signed-off-by: Taehee Yoo <ap420073@gmail.com> --- drivers/net/vxlan.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)