odhcp6c RENEW timeout issue leads to OOM/OOPS [Was: Re: QEMU x86/64 ubus issues ... ]

[Hans Dedecker]

Hi Petr

On Thu, Nov 26, 2020 at 9:58 AM Petr Štetiar <ynezz at true.cz> wrote:
>
> Hi Hans,
>
> I've tried to ping you on IRC few days ago as I've found some strange issue
> with odhcp6c which leads to OOM/OOPS[1] (log with just the important parts).
> It simply happens every time after about 10 hours for me when I boot the system
> in QEMU and have LAN/WAN networks connected there.
>
> It looks like that RENEW retry timeout is being decremented from 13060s down to
> 1s during those few hours, then it goes in the crazy loop and it seems to trash
> the machine completely, sometimes OOMs, sometimes OOPS and reboots due to the
> squashfs issues.
Thank you for the traces;it looks like the reply message in response
to the renew message does not update the renew time which is strange.
Is it possible to have a pcap trace of the DHCPv6 messages on the wan ?
I hope to find some time next weekend to investigate the issue further

Hans
>
> Nothing is happening on that machine, I just boot it and then let it idle.
>
> I've also uploaded complete unfiltered syslog[2] for you.  I'm able to
> reproduce it easily, so happy to help test the fix.
>
> This is on latest and greatest master, x86/64 in QEMU. Thanks!
>
> 1. http://sprunge.us/vv0Idx
> 2. http://ynezz.true.cz/openwrt/odhcp6c/syslog.log.gz
>
> Cheers,
>
> Petr