Re: [PATCH] hid: asus: asus_report_fixup: fix potential read out of bounds

[Dan Carpenter]

On Tue, May 28, 2024 at 12:05:39AM -0500, Andrew Ballance wrote:
> #syz test
> 
> there may be a read out of the bounds of rdesc.
> this adds bounds checks
> 
> Signed-off-by: Andrew Ballance <andrewjballance@xxxxxxxxx>
> ---
>  drivers/hid/hid-asus.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 02de2bf4f790..37e6d25593c2 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -1204,8 +1204,8 @@ static __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
>  	}
>  
>  	/* match many more n-key devices */
> -	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
> -		for (int i = 0; i < *rsize + 1; i++) {
> +	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD && *rsize > 15) {
> +		for (int i = 0; i < *rsize - 15; i++) {

Yep.  This looks correct.  Please resend with a complete commit message
and a fixes tag etc.

>  			/* offset to the count from 0x5a report part always 14 */
>  			if (rdesc[i] == 0x85 && rdesc[i + 1] == 0x5a &&
>  			    rdesc[i + 14] == 0x95 && rdesc[i + 15] == 0x05) {

regards,
dan carpenter