2021-02-15 17:34:38

by Colin King

Subject: [PATCH][next] HID: playstation: fix array size comparison (off-by-one)

From: Colin Ian King <[email protected]>

The comparison of value with the array size ps_gamepad_hat_mapping
appears to be off-by-one. Fix this by using >= rather than > for the
size comparison.

Addresses-Coverity: ("Out-of-bounds read")
Fixes: bc2e15a9a022 ("HID: playstation: initial DualSense USB support.")
Signed-off-by: Colin Ian King <[email protected]>
---
drivers/hid/hid-playstation.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 408b651174cf..568a3a067c88 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -1064,7 +1064,7 @@ static int dualsense_parse_report(struct ps_device *ps_dev, struct hid_report *r
input_report_abs(ds->gamepad, ABS_RZ, ds_report->rz);

value = ds_report->buttons[0] & DS_BUTTONS0_HAT_SWITCH;
- if (value > ARRAY_SIZE(ps_gamepad_hat_mapping))
+ if (value >= ARRAY_SIZE(ps_gamepad_hat_mapping))
value = 8; /* center */
input_report_abs(ds->gamepad, ABS_HAT0X, ps_gamepad_hat_mapping[value].x);
input_report_abs(ds->gamepad, ABS_HAT0Y, ps_gamepad_hat_mapping[value].y);
--
2.30.0

2021-02-17 21:22:55

by Benjamin Tissoires

Subject: Re: [PATCH][next] HID: playstation: fix array size comparison (off-by-one)

On Mon, Feb 15, 2021 at 5:39 PM Colin King <[email protected]> wrote:
>
> From: Colin Ian King <[email protected]>
>
> The comparison of value with the array size ps_gamepad_hat_mapping
> appears to be off-by-one. Fix this by using >= rather than > for the
> size comparison.
>
> Addresses-Coverity: ("Out-of-bounds read")
> Fixes: bc2e15a9a022 ("HID: playstation: initial DualSense USB support.")
> Signed-off-by: Colin Ian King <[email protected]>
> ---

Good catch.

Applied to for-5.12/playstation-v2

Cheers,
Benjamin

> drivers/hid/hid-playstation.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
> index 408b651174cf..568a3a067c88 100644
> --- a/drivers/hid/hid-playstation.c
> +++ b/drivers/hid/hid-playstation.c
> @@ -1064,7 +1064,7 @@ static int dualsense_parse_report(struct ps_device *ps_dev, struct hid_report *r
> input_report_abs(ds->gamepad, ABS_RZ, ds_report->rz);
>
> value = ds_report->buttons[0] & DS_BUTTONS0_HAT_SWITCH;
> - if (value > ARRAY_SIZE(ps_gamepad_hat_mapping))
> + if (value >= ARRAY_SIZE(ps_gamepad_hat_mapping))
> value = 8; /* center */
> input_report_abs(ds->gamepad, ABS_HAT0X, ps_gamepad_hat_mapping[value].x);
> input_report_abs(ds->gamepad, ABS_HAT0Y, ps_gamepad_hat_mapping[value].y);
> --
> 2.30.0
>