2018-10-17 00:15:36

by Dmitry Torokhov

Subject: [PATCH] Input: synaptics - avoid using uninitialized variable when probing

synaptics_detect() does not check whether sending commands to the
device succeeds and instead relies on getting unique data from the
device. Let's make sure we seed entire buffer with zeroes to make sure
we not use garbage on stack that just happen to be 0x47.

Reported-by: [email protected]
Signed-off-by: Dmitry Torokhov <[email protected]>
---
drivers/input/mouse/synaptics.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 55d33500d55e..5e85f3cca867 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -99,9 +99,7 @@ static int synaptics_mode_cmd(struct psmouse *psmouse, u8 mode)
int synaptics_detect(struct psmouse *psmouse, bool set_properties)
{
struct ps2dev *ps2dev = &psmouse->ps2dev;
- u8 param[4];
-
- param[0] = 0;
+ u8 param[4] = { 0 };

ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
--
2.19.1.331.ge82ca0e54c-goog


--
Dmitry

2018-10-17 07:05:52

by Benjamin Tissoires

Subject: Re: [PATCH] Input: synaptics - avoid using uninitialized variable when probing

On Wed, Oct 17, 2018 at 2:14 AM Dmitry Torokhov
<[email protected]> wrote:
>
> synaptics_detect() does not check whether sending commands to the
> device succeeds and instead relies on getting unique data from the
> device. Let's make sure we seed entire buffer with zeroes to make sure
> we not use garbage on stack that just happen to be 0x47.
>
> Reported-by: [email protected]
> Signed-off-by: Dmitry Torokhov <[email protected]>
> ---

Reviewed-by: Benjamin Tissoires <[email protected]>

Cheers,
Benjamin

> drivers/input/mouse/synaptics.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
> index 55d33500d55e..5e85f3cca867 100644
> --- a/drivers/input/mouse/synaptics.c
> +++ b/drivers/input/mouse/synaptics.c
> @@ -99,9 +99,7 @@ static int synaptics_mode_cmd(struct psmouse *psmouse, u8 mode)
> int synaptics_detect(struct psmouse *psmouse, bool set_properties)
> {
> struct ps2dev *ps2dev = &psmouse->ps2dev;
> - u8 param[4];
> -
> - param[0] = 0;
> + u8 param[4] = { 0 };
>
> ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
> ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
> --
> 2.19.1.331.ge82ca0e54c-goog
>
>
> --
> Dmitry

2018-10-19 05:47:11

by Peter Hutterer

Subject: Re: [PATCH] Input: synaptics - avoid using uninitialized variable when probing

On Tue, Oct 16, 2018 at 05:14:43PM -0700, Dmitry Torokhov wrote:
> synaptics_detect() does not check whether sending commands to the
> device succeeds and instead relies on getting unique data from the
> device. Let's make sure we seed entire buffer with zeroes to make sure
> we not use garbage on stack that just happen to be 0x47.
>
> Reported-by: [email protected]
> Signed-off-by: Dmitry Torokhov <[email protected]>

doh, was just about to send out the same patch.

Reviewed-by: Peter Hutterer <[email protected]>

Cheers,
Peter

> ---
> drivers/input/mouse/synaptics.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
> index 55d33500d55e..5e85f3cca867 100644
> --- a/drivers/input/mouse/synaptics.c
> +++ b/drivers/input/mouse/synaptics.c
> @@ -99,9 +99,7 @@ static int synaptics_mode_cmd(struct psmouse *psmouse, u8 mode)
> int synaptics_detect(struct psmouse *psmouse, bool set_properties)
> {
> struct ps2dev *ps2dev = &psmouse->ps2dev;
> - u8 param[4];
> -
> - param[0] = 0;
> + u8 param[4] = { 0 };
>
> ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
> ps2_command(ps2dev, param, PSMOUSE_CMD_SETRES);
> --
> 2.19.1.331.ge82ca0e54c-goog
>
>
> --
> Dmitry