Subject: Re: [PATCH net v2 2/2] net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels

From: Jakub Kicinski <[email-masked]>
Date: Sat, 1 Feb 2025 16:56:58 -0800

On Sat, 1 Feb 2025 14:52:05 +0100 Justin Iurman wrote:
> >> ioam6.sh already triggers the looped cases in both inline and encap
> >> tests. Not sure about seg6 though, and there is no selftest for rpl.  
> > 
> > Right! To be clear I meant just for seg6 and rpl. The ioam6 test
> > is clearly paying off, thanks for putting in the work there! :)  
> 
> Got it. Of course, I'll see what I can do. And glad the ioam6 selftest 
> helped :-) Not sure what the current SRv6 selftests are doing though, 
> but it looks like the "looped cases" were not caught. Probably because 
> the first segment makes it so that the new dst_entry is not the same as 
> the origin (I'll have to double check). I could just add a test with a 
> route matching on a subnet, so that the next segment matches too (i.e., 
> old dst == new dst). Overall, both seg6 and rpl selftests to detect the 
> looped cases would look like "dummy" tests, i.e., useless without 
> kmemleak. Does it sound OK?

Yes, tests written purely for code coverage are perfectly acceptable.
Let alone when they cover paths which where buggy in the past.

FWIW my series was applied now, in case you were waiting.