netdev - Re: [REGRESSION] IPv6 RA default router advertisement fails after kernel 6.12.42 updates

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <CACBcRwKcApHzYssnPj2YQht1yYicTALs03GYkyP88W-9Thmo3w@mail.gmail.com>
Date: Mon, 18 Aug 2025 21:19:15 +0800
From: 喵公子 <miaogongzi0227@...il.com>
To: Greg KH <gregkh@...uxfoundation.org>
Cc: stable@...r.kernel.org, regressions@...ts.linux.dev, edumazet@...gle.com, 
	kuba@...nel.org, sashal@...nel.org, yoshfuji@...ux-ipv6.org, 
	netdev@...r.kernel.org
Subject: Re: [REGRESSION] IPv6 RA default router advertisement fails after
 kernel 6.12.42 updates

Hi Greg,

Thanks for the quick reply.

This regression has been reproduced on Linux 6.12.42 as shipped with
OpenWrt. Currently, OpenWrt only provides kernels from the 6.12.y
stable series, so I was only able to verify on 6.12.42.

I am looping in the networking/IPv6 maintainers so the right people
can take a look at this issue.

Best regards,
gongzi miao

Greg KH <gregkh@...uxfoundation.org> 于2025年8月18日周一 20:25写道：
>
> On Mon, Aug 18, 2025 at 08:03:00PM +0800, 喵公子 wrote:
> > Hi,
> >
> > While testing Linux kernel 6.12.42 on OpenWrt, we observed a
> > regression in IPv6 Router Advertisement (RA) handling for the default
> > router.
> >
> > Affected commits
> >
> > The following commits appear related and may have introduced the issue:
> >
> > ipv6: fix possible infinite loop in fib6_info_uses_dev()：
> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.12.42&id=db65739d406c72776fbdbbc334be827ef05880d2
> >
> > ipv6: prevent infinite loop in rt6_nlmsg_size()：
> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.12.42&id=cd8d8bbd9ced4cc5d06d858f67d4aa87745e8f38
> >
> > ipv6: annotate data-races around rt->fib6_nsiblings：
> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v6.12.42&id=0c58f74f8aa991c2a63bb58ff743e1ff3d584b62
>
> Does this also happen on the latest kernel releases?
>
> Also, please always include the developers/maintainers/mailing list of
> the subsystem where you find an issue with.  Otherwise you are not going
> to reach the developers who can help you out.
>
> thanks,
>
> greg k-h