bridge: vlan: fix possible null ptr derefs on port init and deinit
When a new port is being added we need to make vlgrp available after
rhashtable has been initialized and when removing a port we need to
flush the vlans and free the resources after we're sure noone can use
the port, i.e. after it's removed from the port list and synchronize_rcu
is executed.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 90ac4b0..7e9d60a 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -854,16 +854,20 @@
int nbp_vlan_init(struct net_bridge_port *p)
{
+ struct net_bridge_vlan_group *vg;
int ret = -ENOMEM;
- p->vlgrp = kzalloc(sizeof(struct net_bridge_vlan_group), GFP_KERNEL);
- if (!p->vlgrp)
+ vg = kzalloc(sizeof(struct net_bridge_vlan_group), GFP_KERNEL);
+ if (!vg)
goto out;
- ret = rhashtable_init(&p->vlgrp->vlan_hash, &br_vlan_rht_params);
+ ret = rhashtable_init(&vg->vlan_hash, &br_vlan_rht_params);
if (ret)
goto err_rhtbl;
- INIT_LIST_HEAD(&p->vlgrp->vlan_list);
+ INIT_LIST_HEAD(&vg->vlan_list);
+ /* Make sure everything's committed before publishing vg */
+ smp_wmb();
+ p->vlgrp = vg;
if (p->br->default_pvid) {
ret = nbp_vlan_add(p, p->br->default_pvid,
BRIDGE_VLAN_INFO_PVID |
@@ -875,9 +879,9 @@
return ret;
err_vlan_add:
- rhashtable_destroy(&p->vlgrp->vlan_hash);
+ rhashtable_destroy(&vg->vlan_hash);
err_rhtbl:
- kfree(p->vlgrp);
+ kfree(vg);
goto out;
}