diff options
| author | Petr Machata <petrm@mellanox.com> | 2018-12-18 13:16:00 +0000 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-02-11 17:54:29 +0000 |
| commit | e93901426b7cb921b9e8722b19f9e27c643b3375 (patch) | |
| tree | 9741677536d02ff4ed659bc0c0e0ae0228b60828 | |
| parent | 5133a18f16f11ea4da28011da385e70ce7438cef (diff) | |
vxlan: Fix error path in __vxlan_dev_create()
commit 6db9246871394b3a136cd52001a0763676563840 upstream.
When a failure occurs in rtnl_configure_link(), the current code
calls unregister_netdevice() to roll back the earlier call to
register_netdevice(), and jumps to errout, which calls
vxlan_fdb_destroy().
However unregister_netdevice() calls transitively ndo_uninit, which is
vxlan_uninit(), and that already takes care of deleting the default FDB
entry by calling vxlan_fdb_delete_default(). Since the entry added
earlier in __vxlan_dev_create() is exactly the default entry, the
cleanup code in the errout block always leads to double free and thus a
panic.
Besides, since vxlan_fdb_delete_default() always destroys the FDB entry
with notification enabled, the deletion of the default entry is notified
even before the addition was notified.
Instead, move the unregister_netdevice() call after the manual destroy,
which solves both problems.
Fixes: 0241b836732f ("vxlan: fix default fdb entry netlink notify ordering during netdev create")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | drivers/net/vxlan.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index b1aeef151ed4..941d73b9baff 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -2615,6 +2615,7 @@ static int vxlan_newlink(struct net *net, struct net_device *dev, struct vxlan_dev *vxlan = netdev_priv(dev), *tmp; struct vxlan_rdst *dst = &vxlan->default_dst; struct vxlan_fdb *f = NULL; + bool unregister = false; __u32 vni; int err; bool use_ipv6 = false; @@ -2766,12 +2767,11 @@ static int vxlan_newlink(struct net *net, struct net_device *dev, err = register_netdevice(dev); if (err) goto errout; + unregister = true; err = rtnl_configure_link(dev, NULL); - if (err) { - unregister_netdevice(dev); + if (err) goto errout; - } /* notify default fdb entry */ if (f) @@ -2780,9 +2780,16 @@ static int vxlan_newlink(struct net *net, struct net_device *dev, list_add(&vxlan->next, &vn->vxlan_list); return 0; + errout: + /* unregister_netdevice() destroys the default FDB entry with deletion + * notification. But the addition notification was not sent yet, so + * destroy the entry by hand here. + */ if (f) vxlan_fdb_destroy(vxlan, f); + if (unregister) + unregister_netdevice(dev); return err; } |