2022-03-11 13:08:41

by Tadeusz Struk

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

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