Re: [PATCH net-next v2] net/sched: cls_flow: avoid integer overflow in perturb_period

[Paolo Abeni]

On 11/6/26 07:38, Wei Tao wrote:
> @@ -486,7 +487,13 @@ static int flow_change(struct net *net, struct sk_buff *in_skb,
>   		if (tb[TCA_FLOW_PERTURB]) {
>   			if (mode != FLOW_MODE_HASH)
>   				goto err2;
> -			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
> +			val = nla_get_u32(tb[TCA_FLOW_PERTURB]);
> +			if (val > INT_MAX / HZ) {
> +				NL_SET_ERR_MSG_MOD(extack, "invalid perturb period");
> +				err = -EINVAL;
> +				goto err2;

Sashiko noted the added code could by simplified/substituted with
a  NLA_POLICY_FULL_RANGE(NLA_U32, &range):

https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20261106063823.99731-1-taowei@xxxxxxxxxx

/P