From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752534AbcFNPqO (ORCPT ); Tue, 14 Jun 2016 11:46:14 -0400 Received: from mail.ispras.ru ([83.149.199.45]:44804 "EHLO mail.ispras.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752433AbcFNPqM (ORCPT ); Tue, 14 Jun 2016 11:46:12 -0400 Message-ID: <576017D8.9080207@ispras.ru> Date: Tue, 14 Jun 2016 18:42:32 +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: Eugene Krasnikov CC: Kalle Valo , wcn36xx@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org, Vaishali Thakkar Subject: [ldv-project] [net] wcn36xx: 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 race condition in drivers/net/wireless/ath/wcn36xx/wcn36xx.ko. In wcn36xx_tx -> wcn36xx_start_tx -> wcn36xx_set_tx_data (http://lxr.free-electrons.com/source/drivers/net/wireless/ath/wcn36xx/txrx.c#L176) there is a read of sta_priv->bss_dpu_desc_index and sta_priv->bss_sta_index. In wcn36xx_bss_info_changed -> wcn36xx_smd_config_bss -> wcn36xx_smd_config_bss_rsp (http://lxr.free-electrons.com/source/drivers/net/wireless/ath/wcn36xx/smd.c#L1204) there is a write to the same fields. It seems that the handlers may be called in parallel and inconsistent data may be obtained. The same problem is with sta_priv->sta_index and sta_priv->sta_dpu_desc_index: http://lxr.free-electrons.com/source/drivers/net/wireless/ath/wcn36xx/txrx.c#L181 http://lxr.free-electrons.com/source/drivers/net/wireless/ath/wcn36xx/smd.c#L986 Is it a real bug? Is it enough to add mutex_lock to wcn36xx_set_tx_data? -- Pavel Andrianov Linux Verification Center, ISPRAS web: http://linuxtesting.org e-mail: andrianov@ispras.ru