From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753014AbcFJJZ0 (ORCPT ); Fri, 10 Jun 2016 05:25:26 -0400 Received: from mail.ispras.ru ([83.149.199.45]:38587 "EHLO mail.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751630AbcFJJZX (ORCPT ); Fri, 10 Jun 2016 05:25:23 -0400 Message-ID: <575A788C.5020509@ispras.ru> Date: Fri, 10 Jun 2016 12:21:32 +0400 From: Pavel Andrianov User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Larry Finger CC: Chaoming Li , Kalle Valo , linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Vaishali Thakkar , ldv-project@linuxtesting.org Subject: [ldv-project] [net] rtl8188ee: a potential race condition Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! There is a potential data race in drivers/net/wireless/realtek/rtlwifi/rtl8188ee/rtl8188ee.ko. In the function rtl88ee_gpio_radio_on_off_checking the flag ppsc->rfchange_inprogress is set with a spinlock protection. In the function rtl_ps_set_rf_state the flag is read also under a spinlock. But the function rtl88e_dm_watchdog read it without any locks. As a result rtl88e_dm_watchdog may execute the succeeding code while changing (with the flag rfchange_inprogress == true). I do not exactly determine the consequences, but likely they are not good if there exists such check. Could anybody more confident confirm this? The function rtl_ps_set_rf_state is always called with its parameter [protect_or_not == false]. Is this flag really necessary, if the value 'true' is never used? The function is also set the flag ppsc->rfchange_inprogress and may affect the rtl88e_dm_watchdog as in the previous case. -- Pavel Andrianov Linux Verification Center, ISPRAS web: http://linuxtesting.org e-mail: andrianov@ispras.ru