Re: [PATCH net-next 3/4] ethtool: strset: check nla_len overflow before nla_nest_end

From: Hangbin Liu

Date: Wed Apr 01 2026 - 03:33:49 EST


On Tue, Mar 31, 2026 at 06:46:37PM -0700, Jakub Kicinski wrote:
> On Tue, 31 Mar 2026 11:56:13 +0800 Hangbin Liu wrote:
> > + if (skb_tail_pointer(skb) - (unsigned char *)strings_attr > U16_MAX)
> > + goto nla_put_failure;
>
> bit ugly, let's add a variant of nla_nest_end() which can return
> an error on overflow (without the warning from patch 4) ?

I was tried to not touch nla_nest_end() as it is used everywhere. But it makes
sense to me to add a new function to check this. I'm not very good at naming,
maybe `nla_nest_end_validate()` ? Or any other name if you have?

Thanks
Hangbin
>
> > +
> > nla_nest_end(skb, strings_attr);