Re: stable-security kernel updates

From: Sasha Levin
Date: Thu Apr 21 2016 - 10:02:15 EST

On 04/21/2016 08:36 AM, Greg KH wrote:
> On Thu, Apr 21, 2016 at 07:27:39AM -0400, Sasha Levin wrote:
>> Hey Willy,
>> On 04/21/2016 03:11 AM, Willy Tarreau wrote:
>>> This illustrates exactly what I suspected would happen because that's the
>>> same trouble we all face when picking backports for our respective trees
>>> except that since the selection barrier is much higher here, lots of
>>> important ones will be missing
>> Right. I fully agree that there will be important security commits that'll
>> get missed, whether because they were missed in the stable selection or
>> the stable-security selection.
>> I'd like to point out again that updating the entire stable tree is the
>> preferable way to patch against security (and non-security) issues.
> s/preferable/only/ :)

Really? Even though as I showed updating your stable tree religiously would
still leave you vulnerable to "ancient" privesc exploits?

If anything, the *only* way is updating the entire kernel tree.

>> The
>> stable-security tree is a best-effort solution to provide a stop-gap in
>> between said stable tree updates.
> What are you "stop-gapping" then? The 7-10 days between stable
> releases?

In a perfect world where everyone has a team of kernel hackers on hand
reviewing stable commits, verifying the resulting kernel doesn't regress
their product, and fixes existing regressions for their product it might
be 7-10 days.

In the real world, this process takes much longer.

Doing a full rebase of the kernel tree is a much more costly process than
cherry picking a handful of security commits.