Re: [PATCH] comedi: drivers: ni_tio: Fix arithmetic expression overflow

[Ian Abbott]

On 17/01/2024 12:42, Denis Arefev wrote:
> The value of an arithmetic expression period_ns * 1000 is subject
> to overflow due to a failure to cast operands to a larger data
> type before performing arithmetic
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Denis Arefev <arefev@xxxxxxxxx>
> ---
>   drivers/comedi/drivers/ni_tio.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/comedi/drivers/ni_tio.c b/drivers/comedi/drivers/ni_tio.c
> index da6826d77e60..acc914903c70 100644
> --- a/drivers/comedi/drivers/ni_tio.c
> +++ b/drivers/comedi/drivers/ni_tio.c
> @@ -800,7 +800,7 @@ static int ni_tio_set_clock_src(struct ni_gpct *counter,
>   				GI_PRESCALE_X2(counter_dev->variant) |
>   				GI_PRESCALE_X8(counter_dev->variant), bits);
>   	}
> -	counter->clock_period_ps = period_ns * 1000;
> +	counter->clock_period_ps = period_ns * 1000UL;
>   	ni_tio_set_sync_mode(counter);
>   	return 0;
>   }

Looks good, thanks!

Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>

Could you resend it and Cc Greg Kroah-Hartman 
<gregkh@xxxxxxxxxxxxxxxxxxx> ?  It's more likely to get applied that way 
because I don't maintain my own kernel tree for comedi.  Feel free to 
add my Reviewed-by line.

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