vlan: Fix register_vlan_dev() error path

[ Upstream commit 6b863d1d3239eff0f45c2e6e672f5b56db828db0 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index fe649081fbdcc192426bfc1639068110b2ba6717..db09b94663542deea4616b1fac31f6ecbb9308b3 100644 (file)
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -287,8 +287,11 @@ 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;
 }