Re: [PATCH net-next] net: macb: Validate the value of base_time properly

["Karumanchi, Vineeth" <vineeth@amd.com>]

On 9/1/2025 9:59 PM, Chandra Mohan Sundar wrote:
> In macb_taprio_setup_replace(), the value of start_time is being
> compared against zero which would never be true since start_time
> is an unsigned value. Due to this there is a chance that an
> incorrect config base time value can be used for computation.
> 
> Fix by checking the value of conf->base_time directly.
> This issue was reported by static coverity analyzer.
> 
> Fixes: 89934dbf169e3 ("net: macb: Add TAPRIO traffic scheduling support")
> Signed-off-by: Chandra Mohan Sundar <chandramohan.explore@gmail.com>

Reviewed-by: Vineeth Karumanchi <vineeth.karumanchi@amd.com>

> ---
>   drivers/net/ethernet/cadence/macb_main.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index 290d67da704d..e9b262a0223f 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -4104,7 +4104,7 @@ static int macb_taprio_setup_replace(struct net_device *ndev,
>   		return -EINVAL;
>   	}
>   
> -	if (start_time < 0) {
> +	if (conf->base_time < 0) {
>   		netdev_err(ndev, "Invalid base_time: must be 0 or positive, got %lld\n",
>   			   conf->base_time);
>   		return -ERANGE;

-- 
🙏 Vineeth