Re: net: atm: Spectre v1 fix introduced bug in bcb964012d1b in -stable

[Greg KH]

On Mon, May 20, 2019 at 02:40:14PM +0200, Pavel Machek wrote:
> 
> In lecd_attach, if arg is < 0, it was treated as 0. Spectre v1 fix
> changed that. Bug does not exist in mainline AFAICT.
> 
> Signed-off-by: Pavel Machek <pavel@xxxxxxx>
> # for 4.19.y
> 
> diff --git a/net/atm/lec.c b/net/atm/lec.c
> index ad4f829193f0..ed279cd912f4 100644
> --- a/net/atm/lec.c
> +++ b/net/atm/lec.c
> @@ -731,7 +731,7 @@ static int lecd_attach(struct atm_vcc *vcc, int arg)
>  		i = arg;
>  	if (arg >= MAX_LEC_ITF)
>  		return -EINVAL;
> -	i = array_index_nospec(arg, MAX_LEC_ITF);
> +	i = array_index_nospec(i, MAX_LEC_ITF);
>  	if (!dev_lec[i]) {
>  		int size;
>  

Why is this only for 4.19.y?  What is different in Linus's tree that
makes this not needed there?

thanks,

greg k-h