[PATCH] libertas: Add spinlock to avoid race condition

[PATCH] libertas: Add spinlock to avoid race condition

[Pavel Andrianov]

lbs_mac_event_disconnected may free priv->currenttxskb
while lbs_hard_start_xmit accesses to it.
The patch adds a spinlock for mutual exclusion.

Tested on OLPC XO-1 (usb8388) and XO-1.5 (sd8686) with v4.7-rc3.

Confirmed that lbs_mac_event_disconnected is being called on the
station when hostapd on access point is given SIGHUP.

Signed-off-by: Pavel <andrianov@ispras.ru>
Tested-by: James Cameron <quozl@laptop.org>
---
 drivers/net/wireless/marvell/libertas/cmdresp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/marvell/libertas/cmdresp.c b/drivers/net/wireless/marvell/libertas/cmdresp.c
index c95bf6d..c67ae07 100644
--- a/drivers/net/wireless/marvell/libertas/cmdresp.c
+++ b/drivers/net/wireless/marvell/libertas/cmdresp.c
@@ -27,6 +27,8 @@
 void lbs_mac_event_disconnected(struct lbs_private *priv,
 				bool locally_generated)
 {
+	unsigned long flags;
+
 	if (priv->connect_status != LBS_CONNECTED)
 		return;
 
@@ -46,9 +48,11 @@ void lbs_mac_event_disconnected(struct lbs_private *priv,
 	netif_carrier_off(priv->dev);
 
 	/* Free Tx and Rx packets */
+	spin_lock_irqsave(&priv->driver_lock, flags);
 	kfree_skb(priv->currenttxskb);
 	priv->currenttxskb = NULL;
 	priv->tx_pending_len = 0;
+	spin_unlock_irqrestore(&priv->driver_lock, flags);
 
 	priv->connect_status = LBS_DISCONNECTED;
 
-- 
1.7.11.7

Re: [PATCH] libertas: Add spinlock to avoid race condition

[Vaishali Thakkar]

On Wednesday 15 June 2016 05:04 PM, Pavel Andrianov wrote:
> lbs_mac_event_disconnected may free priv->currenttxskb
> while lbs_hard_start_xmit accesses to it.
> The patch adds a spinlock for mutual exclusion.
> 
> Tested on OLPC XO-1 (usb8388) and XO-1.5 (sd8686) with v4.7-rc3.
> 
> Confirmed that lbs_mac_event_disconnected is being called on the
> station when hostapd on access point is given SIGHUP.
> 
> Signed-off-by: Pavel <andrianov@ispras.ru>
> Tested-by: James Cameron <quozl@laptop.org>

Looks good to me.

Acked-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>

> ---
>  drivers/net/wireless/marvell/libertas/cmdresp.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/wireless/marvell/libertas/cmdresp.c b/drivers/net/wireless/marvell/libertas/cmdresp.c
> index c95bf6d..c67ae07 100644
> --- a/drivers/net/wireless/marvell/libertas/cmdresp.c
> +++ b/drivers/net/wireless/marvell/libertas/cmdresp.c
> @@ -27,6 +27,8 @@
>  void lbs_mac_event_disconnected(struct lbs_private *priv,
>  				bool locally_generated)
>  {
> +	unsigned long flags;
> +
>  	if (priv->connect_status != LBS_CONNECTED)
>  		return;
>  
> @@ -46,9 +48,11 @@ void lbs_mac_event_disconnected(struct lbs_private *priv,
>  	netif_carrier_off(priv->dev);
>  
>  	/* Free Tx and Rx packets */
> +	spin_lock_irqsave(&priv->driver_lock, flags);
>  	kfree_skb(priv->currenttxskb);
>  	priv->currenttxskb = NULL;
>  	priv->tx_pending_len = 0;
> +	spin_unlock_irqrestore(&priv->driver_lock, flags);
>  
>  	priv->connect_status = LBS_DISCONNECTED;
>  
> 

-- 
Vaishali

Re: libertas: Add spinlock to avoid race condition

[Kalle Valo]

Pavel Andrianov <andrianov@ispras.ru> wrote:
> lbs_mac_event_disconnected may free priv->currenttxskb
> while lbs_hard_start_xmit accesses to it.
> The patch adds a spinlock for mutual exclusion.
> 
> Tested on OLPC XO-1 (usb8388) and XO-1.5 (sd8686) with v4.7-rc3.
> 
> Confirmed that lbs_mac_event_disconnected is being called on the
> station when hostapd on access point is given SIGHUP.
> 
> Signed-off-by: Pavel <andrianov@ispras.ru>
> Tested-by: James Cameron <quozl@laptop.org>
> Acked-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>

Thanks, 1 patch applied to wireless-drivers-next.git:

f52b041aed77 libertas: Add spinlock to avoid race condition

-- 
Sent by pwcli
https://patchwork.kernel.org/patch/9178477/