Subject: Re: [PATCH net] net/sched: act_pedit: really ensure the skb is writable

From: Jakub Kicinski <[email-masked]>
Date: Wed, 4 May 2022 08:33:34 -0700

On Wed, 04 May 2022 17:11:25 +0200 Paolo Abeni wrote:
> > For testing stuff like this would it be possible to inject packets
> > with no headers pulled and frags in pages we marked read-only?
> > We can teach netdevsim to do it.  
> 
> We additionally need to ensure that the crafted packets are cloned,
> otherwise the current code is AFAICS fine.

Depends whether skb frags are writable, or not. Or to put it differently
why does skb_cow_data() exist and does what it does.