[57/90] vlan: Fix register_vlan_dev() error path

[Greg KH]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

------------------


From: Eric Dumazet <eric.dumazet@xxxxxxxxx>

[ 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@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
 net/8021q/vlan.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- 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;
 }
 


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