netdev - [ldv-project] [net] libertas: potential race condition

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Message-ID: <57569424.9040906@ispras.ru>
Date:	Tue, 07 Jun 2016 13:30:12 +0400
From:	Pavel Andrianov <andrianov@...ras.ru>
To:	Kalle Valo <kvalo@...eaurora.org>
CC:	libertas-dev@...ts.infradead.org, linux-wireless@...r.kernel.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	vaishali.thakkar@...cle.com, LDV list <ldv-project@...ras.ru>
Subject: [ldv-project] [net] libertas: potential race condition

Hi!

There is a potential race condition in 
drivers/net/wireless/libertas/libertas.ko.
In the function lbs_hard_start_xmit(..), line 159, a socket buffer is 
written to priv->current_skb with a spin_lock protection.
In the function lbs_mac_event_disconnected(..), lines 50-51, the field 
current_skb is cleaned. There is no protection used. The corresponding 
handlers are activated at the same time in lbs_start_card(..) and then 
may be executed simultaneously. Note, there are two structures 
lbs_netdev_ops and mesh_netdev_ops, which have the target handler 
lbs_hard_start_xmit.
Is it a real race or I have missed something?

-- 
Pavel Andrianov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org
e-mail: andrianov@...ras.ru