Re: [regression] TCP_MD5SIG on established sockets

From: Mathieu Desnoyers
Date: Tue Jun 30 2020 - 16:39:54 EST


----- On Jun 30, 2020, at 4:30 PM, Eric Dumazet edumazet@xxxxxxxxxx wrote:

> On Tue, Jun 30, 2020 at 1:21 PM David Miller <davem@xxxxxxxxxxxxx> wrote:
>>
>> From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>> Date: Tue, 30 Jun 2020 12:43:21 -0700
>>
>> > If you're not willing to do the work to fix it, I will revert that
>> > commit.
>>
>> Please let me handle this situation instead of making threats, this
>> just got reported.
>>
>> Thank you.
>>
>
> Also keep in mind the commit fixed a security issue, since we were
> sending on the wire
> garbage bytes from the kernel.
>
> We can not simply revert it and hope for the best.
>
> I find quite alarming vendors still use TCP MD5 "for security
> reasons", but none of them have contributed to it in linux kernel
> since 2018
> (Time of the 'buggy patch')

I'm helping a customer increase their contributions and feedback to upstream.
As we can see, they have accumulated some backlog over time.

Clearly reverting a security fix is not acceptable here. Coming up with a
proper ABI-compatible fix should not be out of our reach though.

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com