Re: [PATCH] ueagle-atm: enforce boundary check for sync_wait[]

[Stanislaw Gruszka <stf_xl@wp.pl>]

On Mon, Apr 07, 2025 at 04:00:00PM +0300, Alexey V. Vissarionov wrote:
> After several increments of modem_index (e.g. after plugging and
> removing the device several times) modem_index may reach NB_MODEM
> value causing the out-of-boundary sync_wait[] array access.
> 
> Found by ALT Linux Team (altlinux.org) and Linux Verification Center
> (linuxtesting.org).
> 
> Fixes: b72458a80c75 ("[PATCH] USB: Eagle and ADI 930 usb adsl modem driver")
> Signed-off-by: Alexey V. Vissarionov <gremlin@altlinux.org>

Acked-by: Stanislaw Gruszka <stf_xl@wp.pl>

> ---
>  drivers/usb/atm/ueagle-atm.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c
> index cd0f7b4bd82ab132..436412b62c910e2f 100644
> --- a/drivers/usb/atm/ueagle-atm.c
> +++ b/drivers/usb/atm/ueagle-atm.c
> @@ -2500,7 +2500,9 @@ static int uea_bind(struct usbatm_data *usbatm, struct usb_interface *intf,
>  	if (ifnum != UEA_INTR_IFACE_NO)
>  		return -ENODEV;
>  
> -	usbatm->flags = (sync_wait[modem_index] ? 0 : UDSL_SKIP_HEAVY_INIT);
> +	usbatm->flags =
> +		modem_index < NB_MODEM && sync_wait[modem_index] ?
> +		0 : UDSL_SKIP_HEAVY_INIT;
>  
>  	/* interface 1 is for outbound traffic */
>  	ret = claim_interface(usb, usbatm, UEA_US_IFACE_NO);
> 
> -- 
> Alexey V. Vissarionov
> gremlin ПРИ altlinux ТЧК org; +vii-cmiii-ccxxix-lxxix-xlii
> GPG: 0D92F19E1C0DC36E27F61A29CD17E2B43D879005 @ hkp://keys.gnupg.net