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From: Pavel Andrianov <andrianov@ispras.ru>
To: Eugene Krasnikov <k.eugene.e@gmail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>,
	wcn36xx@lists.infradead.org, linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	ldv-project@linuxtesting.org,
	Vaishali Thakkar <vaishali.thakkar@oracle.com>
Subject: [ldv-project] [net] wcn36xx: potential race condition
Date: Tue, 14 Jun 2016 18:42:32 +0400	[thread overview]
Message-ID: <576017D8.9080207@ispras.ru> (raw)

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

                 reply	other threads:[~2016-06-14 15:46 UTC|newest]

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