vlan: Fix register_vlan_dev() error path

In case register_netdevice() returns an error, and a new vlan_group
was allocated and inserted in vlan_group_hash[] we call
vlan_group_free() without deleting group from hash table. Future
lookups can give infinite loops or crashes.

We must delete the vlan_group using RCU safe procedure.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 8836575f9d79dcd9b28c1cfa7d01d034dde9f0c5..a29c5ab5815cef5887f99a381a89e9bc2c312b26 100644 (file)
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -281,8 +281,11 @@ out_uninit_applicant:
        if (ngrp)
                vlan_gvrp_uninit_applicant(real_dev);
 out_free_group:
-       if (ngrp)
-               vlan_group_free(ngrp);
+       if (ngrp) {
+               hlist_del_rcu(&ngrp->hlist);
+               /* Free the group, after all cpu's are done. */
+               call_rcu(&ngrp->rcu, vlan_rcu_free);
+       }
        return err;
 }