wifi: cfg80211: fix memory leak in query_regdb_file()

In the function query_regdb_file() the alpha2 parameter is duplicated
using kmemdup() and subsequently freed in regdb_fw_cb(). However,
request_firmware_nowait() can fail without calling regdb_fw_cb() and
thus leak memory.

Fixes: 007f6c5e ("cfg80211: support loading regulatory database as firmware file")
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/wireless/reg.c

@@ -1084,6 +1084,8 @@ MODULE_FIRMWARE("regulatory.db");
 
 static int query_regdb_file(const char *alpha2)
 {
+	int err;
+
 	ASSERT_RTNL();
 
 	if (regdb)
@@ -1093,9 +1095,13 @@ static int query_regdb_file(const char *alpha2)
 	if (!alpha2)
 		return -ENOMEM;
 
-	return request_firmware_nowait(THIS_MODULE, true, "regulatory.db",
-				       &reg_pdev->dev, GFP_KERNEL,
-				       (void *)alpha2, regdb_fw_cb);
+	err = request_firmware_nowait(THIS_MODULE, true, "regulatory.db",
+				      &reg_pdev->dev, GFP_KERNEL,
+				      (void *)alpha2, regdb_fw_cb);
+	if (err)
+		kfree(alpha2);
+
+	return err;
 }
 
 int reg_reload_regdb(void)