net: dsa: fix incorrect function pointer check for MRP ring roles

The cross-chip notifier boilerplate code meant to check the presence of
ds->ops->port_mrp_add_ring_role before calling it, but checked
ds->ops->port_mrp_add instead, before calling
ds->ops->port_mrp_add_ring_role.

Therefore, a driver which implements one operation but not the other
would trigger a NULL pointer dereference.

There isn't any such driver in DSA yet, so there is no reason to
backport the change. Issue found through code inspection.

Cc: Horatiu Vultur <horatiu.vultur@microchip.com>
Fixes: c595c4330da0 ("net: dsa: add MRP support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index 393f2d8..260d8e7 100644 (file)
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -729,7 +729,7 @@ static int
 dsa_switch_mrp_add_ring_role(struct dsa_switch *ds,
                             struct dsa_notifier_mrp_ring_role_info *info)
 {
-       if (!ds->ops->port_mrp_add)
+       if (!ds->ops->port_mrp_add_ring_role)
                return -EOPNOTSUPP;
 
        if (ds->index == info->sw_index)
@@ -743,7 +743,7 @@ static int
 dsa_switch_mrp_del_ring_role(struct dsa_switch *ds,
                             struct dsa_notifier_mrp_ring_role_info *info)
 {
-       if (!ds->ops->port_mrp_del)
+       if (!ds->ops->port_mrp_del_ring_role)
                return -EOPNOTSUPP;
 
        if (ds->index == info->sw_index)