wifi: iwlwifi: mvm: fix size check for fw_link_id

Check that fw_link_id does not exceed the size of link_id_to_link_conf
array. There's no any codepath that can cause that, but it's still
safer to verify in case fw_link_id gets corrupted.

Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20231017115047.3385bd11f423.I2d30fdb464f951c648217553c47901857a0046c7@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/link.c

@@ -60,7 +60,7 @@ int iwl_mvm_add_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	if (link_info->fw_link_id == IWL_MVM_FW_LINK_ID_INVALID) {
 		link_info->fw_link_id = iwl_mvm_get_free_fw_link_id(mvm,
 								    mvmvif);
-		if (link_info->fw_link_id == IWL_MVM_FW_LINK_ID_INVALID)
+		if (link_info->fw_link_id >= ARRAY_SIZE(mvm->link_id_to_link_conf))
 			return -EINVAL;
 
 		rcu_assign_pointer(mvm->link_id_to_link_conf[link_info->fw_link_id],
@@ -243,7 +243,7 @@ int iwl_mvm_remove_link(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	int ret;
 
 	if (WARN_ON(!link_info ||
-		    link_info->fw_link_id == IWL_MVM_FW_LINK_ID_INVALID))
+		    link_info->fw_link_id >= ARRAY_SIZE(mvm->link_id_to_link_conf)))
 		return -EINVAL;
 
 	RCU_INIT_POINTER(mvm->link_id_to_link_conf[link_info->fw_link_id],