panic: sackhint bytes rtx >= 0

[Andriy Gapon]

On 25/02/2021 20:20, Michael Tuexen wrote:
>> On 25. Feb 2021, at 19:08, Andriy Gapon <avg at FreeBSD.org> wrote:
>>
>> On 24/02/2021 00:40, Scheffenegger, Richard wrote:
>>> Hi Andriy,
>>>
>>> I guess I am currently the person who has the most recent knowledge about that
>>> part of the base stack…
>>>
>>> Do you happen to have more (preceding) information about this, or a way to
>>> reproduce this?
>> Unfortunately, no.  It "just happened".
>> There was no unusual activity at the time of the crash.
>> At least, from a user / administrator perspective.
> So you did not use specific TCP stacks or congestion control modules?

Correct.
The default stack and congestion control (if any).

>>> Are you running any special stack (RACK, BBR) which may have switched back to
>>> the base stack in the middle of a loss recovery (I suspected at one point that
>>> this may cause issues, potentially)?
>> I do not have any customizations to the network stack, everything at defaults.
>>
>>> Or was something done with the ipfw that may have temporarily impacted a tcp
>>> session?
>> I use pf as a firewall.  I did not touch it at the time of the crash.
> Does pf change the packets?

Not sure.
If only this rule: scrub in all fragment reassemble
All others are just block and pass (no NAT even).

-- 
Andriy Gapon