Re: [PATCH 6/7] input: alps: Add sanity checks for non DualPoint devices

[Dmitry Torokhov]

On Fri, Nov 14, 2014 at 08:38:25PM +0100, Pali Rohár wrote:
> This patch adds sanity checks and reject trackstick packets from ALPS devices
> which do not have trackstick present (those without ALPS_DUALPOINT flag).
> 
> Make sure that driver does not process some bogus packets as trackstick data
> when there is no trackstick packet. Patch also write warning do dmesg so
> possible problems with driver (e.g received invalid data) will be visible
> for debugging.
> 
> Signed-off-by: Pali Rohár <pali.rohar@xxxxxxxxx>

Applied, thank you.

> ---
>  drivers/input/mouse/alps.c |   22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
> index 2b7b74d..770bec5 100644
> --- a/drivers/input/mouse/alps.c
> +++ b/drivers/input/mouse/alps.c
> @@ -475,6 +475,13 @@ static void alps_process_trackstick_packet_v3(struct psmouse *psmouse)
>  	struct input_dev *dev = priv->dev2;
>  	int x, y, z, left, right, middle;
>  
> +	/* It should be a DualPoint when received trackstick packet */
> +	if (!(priv->flags & ALPS_DUALPOINT)) {
> +		psmouse_warn(psmouse,
> +			"Rejected trackstick packet from non DualPoint device");
> +		return;
> +	}
> +
>  	/* Sanity check packet */
>  	if (!(packet[0] & 0x40)) {
>  		psmouse_dbg(psmouse, "Bad trackstick packet, discarding\n");
> @@ -699,7 +706,8 @@ static void alps_process_touchpad_packet_v3_v5(struct psmouse *psmouse)
>  
>  	alps_report_semi_mt_data(psmouse, fingers);
>  
> -	if (!(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS)) {
> +	if ((priv->flags & ALPS_DUALPOINT) &&
> +	    !(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS)) {
>  		input_report_key(dev2, BTN_LEFT, f->ts_left);
>  		input_report_key(dev2, BTN_RIGHT, f->ts_right);
>  		input_report_key(dev2, BTN_MIDDLE, f->ts_middle);
> @@ -743,8 +751,11 @@ static void alps_process_packet_v6(struct psmouse *psmouse)
>  	 */
>  	if (packet[5] == 0x7F) {
>  		/* It should be a DualPoint when received Trackpoint packet */
> -		if (!(priv->flags & ALPS_DUALPOINT))
> +		if (!(priv->flags & ALPS_DUALPOINT)) {
> +			psmouse_warn(psmouse,
> +			"Rejected trackstick packet from non DualPoint device");
>  			return;
> +		}
>  
>  		/* Trackpoint packet */
>  		x = packet[1] | ((packet[3] & 0x20) << 2);
> @@ -962,6 +973,13 @@ static void alps_process_trackstick_packet_v7(struct psmouse *psmouse)
>  	struct input_dev *dev2 = priv->dev2;
>  	int x, y, z, left, right, middle;
>  
> +	/* It should be a DualPoint when received trackstick packet */
> +	if (!(priv->flags & ALPS_DUALPOINT)) {
> +		psmouse_warn(psmouse,
> +			"Rejected trackstick packet from non DualPoint device");
> +		return;
> +	}
> +
>  	/*
>  	 *        b7 b6 b5 b4 b3 b2 b1 b0
>  	 * Byte0   0  1  0  0  1  0  0  0
> -- 
> 1.7.9.5
> 

-- 
Dmitry
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