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Date: Fri, 31 May 2024 11:59:39 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Andrew Ballance <andrewjballance@gmail.com>
Cc: syzbot+07762f019fd03d01f04c@syzkaller.appspotmail.com,
	benjamin.tissoires@redhat.com, bentiss@kernel.org, jikos@kernel.org,
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Subject: Re: [PATCH] hid: asus: asus_report_fixup: fix potential read out of
 bounds
Message-ID: <d87335b8-9eae-4689-87b4-b581c0b28c9b@moroto.mountain>
References: <000000000000915d550619389e8a@google.com>
 <20240528050555.1150628-1-andrewjballance@gmail.com>
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In-Reply-To: <20240528050555.1150628-1-andrewjballance@gmail.com>

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@gmail.com>
> ---
>  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