Re: [PATCH v4] Documentation: Document the Linux Kernel CVE process

[Josh Poimboeuf]

On Thu, Feb 15, 2024 at 01:10:55PM +0100, Greg Kroah-Hartman wrote:
> +Note, due to the layer at which the Linux kernel is in a system, almost
> +any bug might be exploitable to compromise the security of the kernel,
> +but the possibility of exploitation is often not evident when the bug is
> +fixed.

By this paranoid black-and-white logic, any mainline commit could have a
yet-to-be-discovered regression resulting in a catastrophic
vulnerability.

Should we stay one step ahead and just open a CVE for every mainline
commit?

Problem solved, all "vulnerabilities" have been identified!  False
positives be damned!

For that matter, why don't we do as Thomas has suggested and hardcode
NR_CPUS to zero!

> Because of this, the CVE assignment team is overly cautious and
> +assign CVE numbers to any bugfix that they identify.  This
> +explains the seemingly large number of CVEs that are issued by the Linux
> +kernel team.

How does this match up with the definition of a vulnerabilty?

  An instance of one or more weaknesses in a Product that can be
  exploited, causing a negative impact to confidentiality, integrity, or
  availability; a set of conditions or behaviors that allows the
  violation of an explicit or implicit security policy.

Bug != vulnerability.  Otherwise the definition of a vulnerability would
be much simpler, i.e., "any software defect".

If a CVE is created without any analysis and doesn't describe how the
bug can be exploited then it's completely useless.

Who is this process helping?

- Not users of -stable since they already know they need to be on the
  latest version.

- Not distros or their users as it's just flooding them with low quality
  CVEs which have no analysis or scoring.

And enterprise distros will never be able to rebase onto -stable,
especially for older streams for which they have to be very selective,
in order to avoid destabilizing them.  As you say, "a bug is a bug".

If the problem is low CVE quality then of course it makes a lot of sense
for kernel.org to become a CNA in order to take a leadership role in
helping define and improve the process for its users.  But it makes no
sense to "fix" it by making CVE quality *vastly* lower by flooding
people with useless CVEs.

-- 
Josh