mlxsw: Verify the accessed index doesn't exceed the array length

There are few cases in which an array index queried from a fw register,
is accessed without any validation that it doesn't exceed the array
length.

Add a proper length validation, so accessing memory past the end of an
array will be forbidden.
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/minimal.c

@@ -234,6 +234,7 @@ static void mlxsw_m_port_remove(struct mlxsw_m *mlxsw_m, u8 local_port)
 static int mlxsw_m_port_module_map(struct mlxsw_m *mlxsw_m, u8 local_port,
 				   u8 *last_module)
 {
+	unsigned int max_ports = mlxsw_core_max_ports(mlxsw_m->core);
 	u8 module, width;
 	int err;
 
@@ -249,6 +250,9 @@ static int mlxsw_m_port_module_map(struct mlxsw_m *mlxsw_m, u8 local_port,
 	if (module == *last_module)
 		return 0;
 	*last_module = module;
+
+	if (WARN_ON_ONCE(module >= max_ports))
+		return -EINVAL;
 	mlxsw_m->module_to_port[module] = ++mlxsw_m->max_ports;
 
 	return 0;

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

@@ -2125,9 +2125,14 @@ static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg,
 	struct mlxsw_sp *mlxsw_sp = priv;
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	enum mlxsw_reg_pude_oper_status status;
+	unsigned int max_ports;
 	u8 local_port;
 
+	max_ports = mlxsw_core_max_ports(mlxsw_sp->core);
 	local_port = mlxsw_reg_pude_local_port_get(pude_pl);
+
+	if (WARN_ON_ONCE(local_port >= max_ports))
+		return;
 	mlxsw_sp_port = mlxsw_sp->ports[local_port];
 	if (!mlxsw_sp_port)
 		return;

drivers/net/ethernet/mellanox/mlxsw/spectrum_ptp.c

@@ -568,10 +568,13 @@ void mlxsw_sp1_ptp_got_timestamp(struct mlxsw_sp *mlxsw_sp, bool ingress,
 				 u8 domain_number, u16 sequence_id,
 				 u64 timestamp)
 {
+	unsigned int max_ports = mlxsw_core_max_ports(mlxsw_sp->core);
 	struct mlxsw_sp_port *mlxsw_sp_port;
 	struct mlxsw_sp1_ptp_key key;
 	u8 types;
 
+	if (WARN_ON_ONCE(local_port >= max_ports))
+		return;
 	mlxsw_sp_port = mlxsw_sp->ports[local_port];
 	if (!mlxsw_sp_port)
 		return;

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -2282,6 +2282,7 @@ static void mlxsw_sp_router_neigh_ent_ipv4_process(struct mlxsw_sp *mlxsw_sp,
 						   char *rauhtd_pl,
 						   int ent_index)
 {
+	u64 max_rifs = MLXSW_CORE_RES_GET(mlxsw_sp->core, MAX_RIFS);
 	struct net_device *dev;
 	struct neighbour *n;
 	__be32 dipn;
@@ -2290,6 +2291,8 @@ static void mlxsw_sp_router_neigh_ent_ipv4_process(struct mlxsw_sp *mlxsw_sp,
 
 	mlxsw_reg_rauhtd_ent_ipv4_unpack(rauhtd_pl, ent_index, &rif, &dip);
 
+	if (WARN_ON_ONCE(rif >= max_rifs))
+		return;
 	if (!mlxsw_sp->router->rifs[rif]) {
 		dev_err_ratelimited(mlxsw_sp->bus_info->dev, "Incorrect RIF in neighbour entry\n");
 		return;

drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c

@@ -2520,6 +2520,7 @@ static void mlxsw_sp_fdb_notify_mac_process(struct mlxsw_sp *mlxsw_sp,
 					    char *sfn_pl, int rec_index,
 					    bool adding)
 {
+	unsigned int max_ports = mlxsw_core_max_ports(mlxsw_sp->core);
 	struct mlxsw_sp_port_vlan *mlxsw_sp_port_vlan;
 	struct mlxsw_sp_bridge_device *bridge_device;
 	struct mlxsw_sp_bridge_port *bridge_port;
@@ -2532,6 +2533,9 @@ static void mlxsw_sp_fdb_notify_mac_process(struct mlxsw_sp *mlxsw_sp,
 	int err;
 
 	mlxsw_reg_sfn_mac_unpack(sfn_pl, rec_index, mac, &fid, &local_port);
+
+	if (WARN_ON_ONCE(local_port >= max_ports))
+		return;
 	mlxsw_sp_port = mlxsw_sp->ports[local_port];
 	if (!mlxsw_sp_port) {
 		dev_err_ratelimited(mlxsw_sp->bus_info->dev, "Incorrect local port in FDB notification\n");