1 files changed, 17 insertions, 4 deletions

diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 9b61d09de9b9..6f615b8192f4 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -20,7 +20,7 @@
 
 
 /* Port id is composed of priority and port number.
- * NB: least significant bits of priority are dropped to
+ * NB: some bits of priority are dropped to
  *     make room for more ports.
  */
 static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
@@ -29,6 +29,8 @@ static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
                 | (port_no & ((1<<BR_PORT_BITS)-1));
 }
 
+#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
+
 /* called under bridge lock */
 void br_init_port(struct net_bridge_port *p)
 {
@@ -255,10 +257,14 @@ void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
 }
 
 /* called under bridge lock */
-void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
+int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
 {
-        port_id new_port_id = br_make_port_id(newprio, p->port_no);
+        port_id new_port_id;
+
+        if (newprio > BR_MAX_PORT_PRIORITY)
+                return -ERANGE;
 
+        new_port_id = br_make_port_id(newprio, p->port_no);
         if (br_is_designated_port(p))
                 p->designated_port = new_port_id;
 
@@ -269,14 +275,21 @@ void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
                 br_become_designated_port(p);
                 br_port_state_selection(p->br);
         }
+
+        return 0;
 }
 
 /* called under bridge lock */
-void br_stp_set_path_cost(struct net_bridge_port *p, u32 path_cost)
+int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
 {
+        if (path_cost < BR_MIN_PATH_COST ||
+            path_cost > BR_MAX_PATH_COST)
+                return -ERANGE;
+
         p->path_cost = path_cost;
         br_configuration_update(p->br);
         br_port_state_selection(p->br);
+        return 0;
 }
 
 ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)