Documentation/process: Embargoed hardware security issues

To address the requirements of embargoed hardware issues, like Meltdown,
Spectre, L1TF etc. it is necessary to define and document a process for
handling embargoed hardware security issues.

Following the discussion at the maintainer summit 2018 in Edinburgh
(https://lwn.net/Articles/769417/) the volunteered people have worked
out a process and a Memorandum of Understanding. The latter addresses
the fact that the Linux kernel community cannot sign NDAs for various
reasons.

The initial contact point for hardware security issues is different from
the regular kernel security contact to provide a known and neutral
interface for hardware vendors and researchers. The initial primary
contact team is proposed to be staffed by Linux Foundation Fellows, who
are not associated to a vendor or a distribution and are well connected
in the industry as a whole.

The process is designed with the experience of the past incidents in
mind and tries to address the remaining gaps, so future (hopefully rare)
incidents can be handled more efficiently. It won't remove the fact,
that most of this has to be done behind closed doors, but it is set up
to avoid big bureaucratic hurdles for individual developers.

The process is solely for handling hardware security issues and cannot
be used for regular kernel (software only) security bugs.

This memo can help with hardware companies who, and I quote, "[my
manager] doesn't want to bet his job on the list keeping things secret."
This despite numerous leaks directly from that company over the years,
and none ever so far from the kernel security team. Cognitive
dissidence seems to be a requirement to be a good manager.

To accelerate the adoption of this process, we introduce the concept of
ambassadors in participating companies. The ambassadors are there to
guide people to comply with the process, but are not automatically
involved in the disclosure of a particular incident.

Signed-off-by: Thomas Gleixner <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Reviewed-by: Josh Poimboeuf <[e-mail]>
Acked-by: Laura Abbott <[e-mail]>
Acked-by: Ben Hutchings <[e-mail]>
Reviewed-by: Tyler Hicks <[e-mail]>
Reviewed-by: Konrad Rzeszutek Wilk <[e-mail]>
Reviewed-by: Jiri Kosina <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/process/embargoed-hardware-issues.rst

···
+Embargoed hardware issues
+=========================
+
+Scope
+-----
+
+Hardware issues which result in security problems are a different category
+of security bugs than pure software bugs which  only affect the Linux
+kernel.
+
+Hardware issues like Meltdown, Spectre, L1TF etc. must be treated
+differently because they usually affect all Operating Systems ("OS") and
+therefore need coordination across different OS vendors, distributions,
+hardware vendors and other parties. For some of the issues, software
+mitigations can depend on microcode or firmware updates, which need further
+coordination.
+
+.. _Contact:
+
+Contact
+-------
+
+The Linux kernel hardware security team is separate from the regular Linux
+kernel security team.
+
+The team only handles the coordination of embargoed hardware security
+issues.  Reports of pure software security bugs in the Linux kernel are not
+handled by this team and the reporter will be guided to contact the regular
+Linux kernel security team (:ref:`Documentation/admin-guide/
+<securitybugs>`) instead.
+
+The team can be contacted by email at <[e-mail]>. This
+is a private list of security officers who will help you to coordinate an
+issue according to our documented process.
+
+The list is encrypted and email to the list can be sent by either PGP or
+S/MIME encrypted and must be signed with the reporter's PGP key or S/MIME
+certificate. The list's PGP key and S/MIME certificate are available from
+https://www.kernel.org/....
+
+While hardware security issues are often handled by the affected hardware
+vendor, we welcome contact from researchers or individuals who have
+identified a potential hardware flaw.
+
+Hardware security officers
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The current team of hardware security officers:
+
+  - Linus Torvalds (Linux Foundation Fellow)
+  - Greg Kroah-Hartman (Linux Foundation Fellow)
+  - Thomas Gleixner (Linux Foundation Fellow)
+
+Operation of mailing-lists
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The encrypted mailing-lists which are used in our process are hosted on
+Linux Foundation's IT infrastructure. By providing this service Linux
+Foundation's director of IT Infrastructure security technically has the
+ability to access the embargoed information, but is obliged to
+confidentiality by his employment contract. Linux Foundation's director of
+IT Infrastructure security is also responsible for the kernel.org
+infrastructure.
+
+The Linux Foundation's current director of IT Infrastructure security is
+Konstantin Ryabitsev.
+
+
+Non-disclosure agreements
+-------------------------
+
+The Linux kernel hardware security team is not a formal body and therefore
+unable to enter into any non-disclosure agreements.  The kernel community
+is aware of the sensitive nature of such issues and offers a Memorandum of
+Understanding instead.
+
+
+Memorandum of Understanding
+---------------------------
+
+The Linux kernel community has a deep understanding of the requirement to
+keep hardware security issues under embargo for coordination between
+different OS vendors, distributors, hardware vendors and other parties.
+
+The Linux kernel community has successfully handled hardware security
+issues in the past and has the necessary mechanisms in place to allow
+community compliant development under embargo restrictions.
+
+The Linux kernel community has a dedicated hardware security team for
+initial contact, which oversees the process of handling such issues under
+embargo rules.
+
+The hardware security team identifies the developers (domain experts) who
+will form the initial response team for a particular issue. The initial
+response team can bring in further developers (domain experts) to address
+the issue in the best technical way.
+
+All involved developers pledge to adhere to the embargo rules and to keep
+the received information confidential. Violation of the pledge will lead to
+immediate exclusion from the current issue and removal from all related
+mailing-lists. In addition, the hardware security team will also exclude
+the offender from future issues. The impact of this consequence is a highly
+effective deterrent in our community. In case a violation happens the
+hardware security team will inform the involved parties immediately. If you
+or anyone becomes aware of a potential violation, please report it
+immediately to the Hardware security officers.
+
+
+Process
+^^^^^^^
+
+Due to the globally distributed nature of Linux kernel development,
+face-to-face meetings are almost impossible to address hardware security
+issues.  Phone conferences are hard to coordinate due to time zones and
+other factors and should be only used when absolutely necessary. Encrypted
+email has been proven to be the most effective and secure communication
+method for these types of issues.
+
+Start of Disclosure
+"""""""""""""""""""
+
+Disclosure starts by contacting the Linux kernel hardware security team by
+email. This initial contact should contain a description of the problem and
+a list of any known affected hardware. If your organization builds or
+distributes the affected hardware, we encourage you to also consider what
+other hardware could be affected.
+
+The hardware security team will provide an incident-specific encrypted
+mailing-list which will be used for initial discussion with the reporter,
+further disclosure and coordination.
+
+The hardware security team will provide the disclosing party a list of
+developers (domain experts) who should be informed initially about the
+issue after confirming with the developers  that they will adhere to this
+Memorandum of Understanding and the documented process. These developers
+form the initial response team and will be responsible for handling the
+issue after initial contact. The hardware security team is supporting the
+response team, but is not necessarily involved in the mitigation
+development process.
+
+While individual developers might be covered by a non-disclosure agreement
+via their employer, they cannot enter individual non-disclosure agreements
+in their role as Linux kernel developers. They will, however, agree to
+adhere to this documented process and the Memorandum of Understanding.
+
+
+Disclosure
+""""""""""
+
+The disclosing party provides detailed information to the initial response
+team via the specific encrypted mailing-list.
+
+From our experience the technical documentation of these issues is usually
+a sufficient starting point and further technical clarification is best
+done via email.
+
+Mitigation development
+""""""""""""""""""""""
+
+The initial response team sets up an encrypted mailing-list or repurposes
+an existing one if appropriate. The disclosing party should provide a list
+of contacts for all other parties who have already been, or should be
+informed about the issue. The response team contacts these parties so they
+can name experts who should be subscribed to the mailing-list.
+
+Using a mailing-list is close to the normal Linux development process and
+has been successfully used in developing mitigations for various hardware
+security issues in the past.
+
+The mailing-list operates in the same way as normal Linux development.
+Patches are posted, discussed and reviewed and if agreed on applied to a
+non-public git repository which is only accessible to the participating
+developers via a secure connection. The repository contains the main
+development branch against the mainline kernel and backport branches for
+stable kernel versions as necessary.
+
+The initial response team will identify further experts from the Linux
+kernel developer community as needed and inform the disclosing party about
+their participation. Bringing in experts can happen at any time of the
+development process and often needs to be handled in a timely manner.
+
+Coordinated release
+"""""""""""""""""""
+
+The involved parties will negotiate the date and time where the embargo
+ends. At that point the prepared mitigations are integrated into the
+relevant kernel trees and published.
+
+While we understand that hardware security issues need coordinated embargo
+time, the embargo time should be constrained to the minimum time which is
+required for all involved parties to develop, test and prepare the
+mitigations. Extending embargo time artificially to meet conference talk
+dates or other non-technical reasons is creating more work and burden for
+the involved developers and response teams as the patches need to be kept
+up to date in order to follow the ongoing upstream kernel development,
+which might create conflicting changes.
+
+CVE assignment
+""""""""""""""
+
+Neither the hardware security team nor the initial response team assign
+CVEs, nor are CVEs required for the development process. If CVEs are
+provided by the disclosing party they can be used for documentation
+purposes.
+
+Process ambassadors
+-------------------
+
+For assistance with this process we have established ambassadors in various
+organizations, who can answer questions about or provide guidance on the
+reporting process and further handling. Ambassadors are not involved in the
+disclosure of a particular issue, unless requested by a response team or by
+an involved disclosed party. The current ambassadors list:
+
+  ============= ========================================================
+  ARM
+  AMD
+  IBM
+  Intel
+  Qualcomm
+
+  Microsoft
+  VMware
+  XEN
+
+  Canonical	Tyler Hicks <[e-mail]>
+  Debian	Ben Hutchings <[e-mail]>
+  Oracle	Konrad Rzeszutek Wilk <[e-mail]>
+  Red Hat	Josh Poimboeuf <[e-mail]>
+  SUSE		Jiri Kosina <[e-mail]>
+
+  Amazon
+  Google
+  ============== ========================================================
+
+If you want your organization to be added to the ambassadors list, please
+contact the hardware security team. The nominated ambassador has to
+understand and support our process fully and is ideally well connected in
+the Linux kernel community.
+
+Encrypted mailing-lists
+-----------------------
+
+We use encrypted mailing-lists for communication. The operating principle
+of these lists is that email sent to the list is encrypted either with the
+list's PGP key or with the list's S/MIME certificate. The mailing-list
+software decrypts the email and re-encrypts it individually for each
+subscriber with the subscriber's PGP key or S/MIME certificate. Details
+about the mailing-list software and the setup which is used to ensure the
+security of the lists and protection of the data can be found here:
+https://www.kernel.org/....
+
+List keys
+^^^^^^^^^
+
+For initial contact see :ref:`Contact`. For incident specific mailing-lists
+the key and S/MIME certificate are conveyed to the subscribers by email
+sent from the specific list.
+
+Subscription to incident specific lists
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Subscription is handled by the response teams. Disclosed parties who want
+to participate in the communication send a list of potential subscribers to
+the response team so the response team can validate subscription requests.
+
+Each subscriber needs to send a subscription request to the response team
+by email. The email must be signed with the subscriber's PGP key or S/MIME
+certificate. If a PGP key is used, it must be available from a public key
+server and is ideally connected to the Linux kernel's PGP web of trust. See
+also: https://www.kernel.org/signature.html.
+
+The response team verifies that the subscriber request is valid and adds
+the subscriber to the list. After subscription the subscriber will receive
+email from the mailing-list which is signed either with the list's PGP key
+or the list's S/MIME certificate. The subscriber's email client can extract
+the PGP key or the S/MIME certificate from the signature so the subscriber
+can send encrypted email to the list.
+

Documentation/process/index.rst

···
    submit-checklist
    kernel-docs
    deprecated
+   embargoed-hardware-issues
 
 These are some overall technical guides that have been put here for now for
 lack of a better place.