Subject: Re: [PATCH ipsec-next 2/2] xfrm: policy: replace session decode with flow dissector

From: Florian Westphal <[email-masked]>
Date: Wed, 27 Sep 2023 20:01:29 +0200

kernel test robot <[email-masked]> wrote:
> (please refer to attached dmesg/kmsg for entire log/backtrace)
> 
> 
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <[email-masked]>
> | Closes: https://lore.kernel.org/oe-lkp/[email-masked]
> 
> 
> kern  :warn  : [  173.147140] ------------[ cut here ]------------
> kern :warn : [  173.147759] WARNING: CPU: 12 PID: 2260 at net/core/flow_dissector.c:1096 __skb_flow_dissect (net/core/flow_dissector.c:1096 (discriminator 1)) 

Two options, more 'guess the right netns' in flow dissector:
derive netns from skb->dst->dev.

Or, pass struct net down to xfrm session decode functions.

I'll have a go at option 2 to see how much noise its going to be.