Am Dienstag, den 14.03.2017, 21:14 +0100 schrieb Tobias Herzog:
> Notifications may only be 8 bytes so long. Accessing the 9th and
> 10th byte of unimplemented/unknown notifications may be insecure.
> Also check the length of known notifications before accessing anything
> behind the 8th byte.
> 
> Signed-off-by: Tobias Herzog <t-her...@gmx.de>
> ---
>  drivers/usb/class/cdc-acm.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
> index 40714fe..b99127e 100644
> --- a/drivers/usb/class/cdc-acm.c
> +++ b/drivers/usb/class/cdc-acm.c
> @@ -296,6 +296,12 @@ static void acm_process_notification(struct acm *acm, 
> unsigned char *buf)
>               break;
>  
>       case USB_CDC_NOTIFY_SERIAL_STATE:
> +             if (dr->wLength != 2) {

Endianness

> +                     dev_dbg(&acm->control->dev,
> +                             "%s - malformed serial state\n", __func__);
> +                     break;
> +             }
> +
>               newctrl = get_unaligned_le16(data);
>  
>               if (!acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
> @@ -332,11 +338,10 @@ static void acm_process_notification(struct acm *acm, 
> unsigned char *buf)
>  
>       default:
>               dev_dbg(&acm->control->dev,
> -                     "%s - unknown notification %d received: index %d "
> -                     "len %d data0 %d data1 %d\n",
> +                     "%s - unknown notification %d received: index %d len 
> %d\n",
>                       __func__,
>                       dr->bNotificationType, dr->wIndex,
> -                     dr->wLength, data[0], data[1]);
> +                     dr->wLength);
>       }
>  }
>  

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