Bug#1112535: /usr/lib/systemd/systemd-networkd: segfault after upgrade to 257.8-1~deb13u1, no connectivity after reboot

[Antoine Beaupré]

On 2025-09-06 21:55:38, Michael Tokarev wrote:
> On Sat, 6 Sep 2025 10:34:20 -0400 Robert Edmonds <edmonds at debian.org> wrote:
>> I can confirm that systemd-networkd from the systemd 257.8-1~deb13u1 in
>> stable crashes on configurations with VLAN-aware bridges with a similar
>> stack trace to the one given in [0]. I have also seen this crash in one
>> of the Debian v258 RC's.
>> 
>> The problem seems to be that v257.8 is missing the fix in [1] that was
>> released in v257.9.
>> 
>> [0]: https://github.com/systemd/systemd/issues/38515
>> [1]: https://github.com/systemd/systemd/commit/24c1f6f5ac06b29d39d587ecccb269fd42349307
> It's another confirmation from me as well, -- I rebuilt systemd from
> trixie (13.1) to include this commit in [1], and it works for me as
> well now (was segfaulting the same way as described).

On 2025-09-06 14:52:15, Kevin Otte wrote:
> Just ran headlong into this as well. I'm glad I did my workstation first 
> as my VM host is running the same config and my whole network would now 
> be offline had I applied it there.
>
> I concur with raising the severity of this bug and eagerly await a fixed 
> package.

Hi Michael and Kevin!

Thanks for the confirmations! Could you also confirm that this only
affects bridge-enabled configurations?

This looks otherwise quite terrifying, but I can't imagine this breaks
*all* systemd-networkd setups, does it?

In the meantime, for people who use unattended-upgrades, this should be
enough to keep the package from upgrading until this is resolved:

    apt-mark hold systemd

Good luck!

-- 
During times of universal deceit, telling the truth becomes a
revolutionary act.       - Georges Orwell