bridge: Fix VLAN reference count problem

[ Upstream commit 0e5a82efda872c2469c210957d7d4161ef8f4391 ]

When a VLAN is added on a port, a reference is taken on the
corresponding master VLAN entry. If it does not already exist, then it
is created and a reference taken.

However, in the second case a reference is not really taken when
CONFIG_REFCOUNT_FULL is enabled as refcount_inc() is replaced by
refcount_inc_not_zero().

Fix this by using refcount_set() on a newly created master VLAN entry.

Fixes: 251277598596 ("net, bridge: convert net_bridge_vlan.refcnt from atomic_t to refcount_t")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 233a30040c91fc8e9d26a320bd0696cb64571872..9b8a53568b0f62f41310ada5340e9e943e9794e2 100644 (file)
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -157,6 +157,8 @@ static struct net_bridge_vlan *br_vlan_get_master(struct net_bridge *br, u16 vid
                masterv = br_vlan_find(vg, vid);
                if (WARN_ON(!masterv))
                        return NULL;
+               refcount_set(&masterv->refcnt, 1);
+               return masterv;
        }
        refcount_inc(&masterv->refcnt);