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

Dmitry Torokhov
2015-01-12T00:31:06Z

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@gmail.com>

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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