Re: [PATCH v2] net: ipv6: fix skb_over_panic in __ip6_append_data

[Tadeusz Struk]

On 3/10/22 14:30, Jakub Kicinski wrote:
> > +
> > +			/*
> > +			 *	Check if there is still room for payload
> > +			 */
> TBH I think the check is self-explanatory. Not worth a banner comment,
> for sure.

Ok

> > +			if (fragheaderlen >= mtu) {
> > +				err = -EMSGSIZE;
> > +				kfree_skb(skb);
> > +				goto error;
> > +			}
> Not sure if Willem prefers this placement, but seems like we can lift
> this check out of the loop, as soon as fragheaderlen and mtu are known.

He said to check it before the skb_put() and so I did.
The fragheaderlen is known early, but mtu can be updated inside the loop
by ip6_append_data_mtu() so I'm not sure we can do the check before that.

--
Thanks,
Tadeusz