oss-sec mailing list archives

Re: CVE-2021-20177 kernel: iptables string match rule could result in kernel panic


From: Sasha Levin <sashal () kernel org>
Date: Tue, 12 Jan 2021 11:04:29 -0500

On Tue, Jan 12, 2021 at 03:23:16PM +0000, John Haxby wrote:
On 12 Jan 2021, at 08:04, Greg KH <greg () kroah com> wrote:

I still do not understand why you report issues that are fixed over a
year ago (October 2019) and assign them a CVE like this.  Who does this
help out?  And what about the thousands of other issues that are fixed
in the kernel and not assigned a CVE like this, are they somehow not as
important to your group?

What determines what you want to give a CVE to and what you do not?


I think I can answer that.   There's nothing technical going on here, it's down to the behaviour of the end users of 
enterprise systems.

A lot of those people have a hard time understanding that they do actually want bug fixes and an even harder time 
understanding that they need to actually do something to install those fixes.   (I was once asked if I could fix a problem 
without changing anything, anything at all when the fix was a one-off chmod.)   A CVE number gets attention: think of it as 
getting hold of the customer by the lapels and going nose-to-nose to explain in words of one syllable they if they 
don't update their systems that they will crash and they will get hacked.

Ooh, no, they say, we can't possibly take the risk of updating our systems.  Suppose something goes wrong?   Sheesh.   Suppose, instead, 
someone comes along and sees a known, fixed bug is unfixed and uses that to trash your systems.    Or that you've got a bug that crashes 
the machine once a week for which there's a fix.   But, no, apparently the mythical risk of a tested update vs the actual quantifiable risk 
of leaving the bug unfixed is so great that they'd rather take the real, quantifiable risk.   I suppose that's understandable, after a 
fashion, even though actual regressions are quite rare.

If you present a customer with a CVE number (with or without a score) then they have SLAs which will ensure that that 
fix gets applied.

The subject of this thread is a "vulnerability" that requires root to
exploit and was fixed ages ago.

If we all agree that CVEs (in the context of the kernel, not userspace)
aren't here to provide technical value but rather a marketing scheme,
maybe we should just start treating them as such?

About 95% of the commits that go in the stable tree qualify as CVEs,
maybe the path forward here is to request CVEs for a handful of those,
for each stable release and encourage customers to upgrade more often
that way?

--
Thanks,
Sasha


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