1Embargoed hardware issues
2=========================
3
4Scope
5-----
6
7Hardware issues which result in security problems are a different category
8of security bugs than pure software bugs which only affect the Linux
9kernel.
10
11Hardware issues like Meltdown, Spectre, L1TF etc. must be treated
12differently because they usually affect all Operating Systems ("OS") and
13therefore need coordination across different OS vendors, distributions,
14hardware vendors and other parties. For some of the issues, software
15mitigations can depend on microcode or firmware updates, which need further
16coordination.
17
18.. _Contact:
19
20Contact
21-------
22
23The Linux kernel hardware security team is separate from the regular Linux
24kernel security team.
25
26The team only handles the coordination of embargoed hardware security
27issues.  Reports of pure software security bugs in the Linux kernel are not
28handled by this team and the reporter will be guided to contact the regular
29Linux kernel security team (:ref:`Documentation/admin-guide/
30<securitybugs>`) instead.
31
32The team can be contacted by email at <hardware-security@kernel.org>. This
33is a private list of security officers who will help you to coordinate an
34issue according to our documented process.
35
36The list is encrypted and email to the list can be sent by either PGP or
37S/MIME encrypted and must be signed with the reporter's PGP key or S/MIME
38certificate. The list's PGP key and S/MIME certificate are available from
39https://www.kernel.org/....
40
41While hardware security issues are often handled by the affected hardware
42vendor, we welcome contact from researchers or individuals who have
43identified a potential hardware flaw.
44
45Hardware security officers
46^^^^^^^^^^^^^^^^^^^^^^^^^^
47
48The current team of hardware security officers:
49
50  - Linus Torvalds (Linux Foundation Fellow)
51  - Greg Kroah-Hartman (Linux Foundation Fellow)
52  - Thomas Gleixner (Linux Foundation Fellow)
53
54Operation of mailing-lists
55^^^^^^^^^^^^^^^^^^^^^^^^^^
56
57The encrypted mailing-lists which are used in our process are hosted on
58Linux Foundation's IT infrastructure. By providing this service Linux
59Foundation's director of IT Infrastructure security technically has the
60ability to access the embargoed information, but is obliged to
61confidentiality by his employment contract. Linux Foundation's director of
62IT Infrastructure security is also responsible for the kernel.org
63infrastructure.
64
65The Linux Foundation's current director of IT Infrastructure security is
66Konstantin Ryabitsev.
67
68
69Non-disclosure agreements
70-------------------------
71
72The Linux kernel hardware security team is not a formal body and therefore
73unable to enter into any non-disclosure agreements.  The kernel community
74is aware of the sensitive nature of such issues and offers a Memorandum of
75Understanding instead.
76
77
78Memorandum of Understanding
79---------------------------
80
81The Linux kernel community has a deep understanding of the requirement to
82keep hardware security issues under embargo for coordination between
83different OS vendors, distributors, hardware vendors and other parties.
84
85The Linux kernel community has successfully handled hardware security
86issues in the past and has the necessary mechanisms in place to allow
87community compliant development under embargo restrictions.
88
89The Linux kernel community has a dedicated hardware security team for
90initial contact, which oversees the process of handling such issues under
91embargo rules.
92
93The hardware security team identifies the developers (domain experts) who
94will form the initial response team for a particular issue. The initial
95response team can bring in further developers (domain experts) to address
96the issue in the best technical way.
97
98All involved developers pledge to adhere to the embargo rules and to keep
99the received information confidential. Violation of the pledge will lead to
100immediate exclusion from the current issue and removal from all related
101mailing-lists. In addition, the hardware security team will also exclude
102the offender from future issues. The impact of this consequence is a highly
103effective deterrent in our community. In case a violation happens the
104hardware security team will inform the involved parties immediately. If you
105or anyone becomes aware of a potential violation, please report it
106immediately to the Hardware security officers.
107
108
109Process
110^^^^^^^
111
112Due to the globally distributed nature of Linux kernel development,
113face-to-face meetings are almost impossible to address hardware security
114issues.  Phone conferences are hard to coordinate due to time zones and
115other factors and should be only used when absolutely necessary. Encrypted
116email has been proven to be the most effective and secure communication
117method for these types of issues.
118
119Start of Disclosure
120"""""""""""""""""""
121
122Disclosure starts by contacting the Linux kernel hardware security team by
123email. This initial contact should contain a description of the problem and
124a list of any known affected hardware. If your organization builds or
125distributes the affected hardware, we encourage you to also consider what
126other hardware could be affected.
127
128The hardware security team will provide an incident-specific encrypted
129mailing-list which will be used for initial discussion with the reporter,
130further disclosure and coordination.
131
132The hardware security team will provide the disclosing party a list of
133developers (domain experts) who should be informed initially about the
134issue after confirming with the developers  that they will adhere to this
135Memorandum of Understanding and the documented process. These developers
136form the initial response team and will be responsible for handling the
137issue after initial contact. The hardware security team is supporting the
138response team, but is not necessarily involved in the mitigation
139development process.
140
141While individual developers might be covered by a non-disclosure agreement
142via their employer, they cannot enter individual non-disclosure agreements
143in their role as Linux kernel developers. They will, however, agree to
144adhere to this documented process and the Memorandum of Understanding.
145
146The disclosing party should provide a list of contacts for all other
147entities who have already been, or should be, informed about the issue.
148This serves several purposes:
149
150 - The list of disclosed entities allows communication accross the
151   industry, e.g. other OS vendors, HW vendors, etc.
152
153 - The disclosed entities can be contacted to name experts who should
154   participate in the mitigation development.
155
156 - If an expert which is required to handle an issue is employed by an
157   listed entity or member of an listed entity, then the response teams can
158   request the disclosure of that expert from that entity. This ensures
159   that the expert is also part of the entity's response team.
160
161Disclosure
162""""""""""
163
164The disclosing party provides detailed information to the initial response
165team via the specific encrypted mailing-list.
166
167From our experience the technical documentation of these issues is usually
168a sufficient starting point and further technical clarification is best
169done via email.
170
171Mitigation development
172""""""""""""""""""""""
173
174The initial response team sets up an encrypted mailing-list or repurposes
175an existing one if appropriate.
176
177Using a mailing-list is close to the normal Linux development process and
178has been successfully used in developing mitigations for various hardware
179security issues in the past.
180
181The mailing-list operates in the same way as normal Linux development.
182Patches are posted, discussed and reviewed and if agreed on applied to a
183non-public git repository which is only accessible to the participating
184developers via a secure connection. The repository contains the main
185development branch against the mainline kernel and backport branches for
186stable kernel versions as necessary.
187
188The initial response team will identify further experts from the Linux
189kernel developer community as needed. Bringing in experts can happen at any
190time of the development process and needs to be handled in a timely manner.
191
192If an expert is employed by or member of an entity on the disclosure list
193provided by the disclosing party, then participation will be requested from
194the relevant entity.
195
196If not, then the disclosing party will be informed about the experts
197participation. The experts are covered by the Memorandum of Understanding
198and the disclosing party is requested to acknowledge the participation. In
199case that the disclosing party has a compelling reason to object, then this
200objection has to be raised within five work days and resolved with the
201incident team immediately. If the disclosing party does not react within
202five work days this is taken as silent acknowledgement.
203
204After acknowledgement or resolution of an objection the expert is disclosed
205by the incident team and brought into the development process.
206
207
208Coordinated release
209"""""""""""""""""""
210
211The involved parties will negotiate the date and time where the embargo
212ends. At that point the prepared mitigations are integrated into the
213relevant kernel trees and published.
214
215While we understand that hardware security issues need coordinated embargo
216time, the embargo time should be constrained to the minimum time which is
217required for all involved parties to develop, test and prepare the
218mitigations. Extending embargo time artificially to meet conference talk
219dates or other non-technical reasons is creating more work and burden for
220the involved developers and response teams as the patches need to be kept
221up to date in order to follow the ongoing upstream kernel development,
222which might create conflicting changes.
223
224CVE assignment
225""""""""""""""
226
227Neither the hardware security team nor the initial response team assign
228CVEs, nor are CVEs required for the development process. If CVEs are
229provided by the disclosing party they can be used for documentation
230purposes.
231
232Process ambassadors
233-------------------
234
235For assistance with this process we have established ambassadors in various
236organizations, who can answer questions about or provide guidance on the
237reporting process and further handling. Ambassadors are not involved in the
238disclosure of a particular issue, unless requested by a response team or by
239an involved disclosed party. The current ambassadors list:
240
241  ============= ========================================================
242  ARM
243  AMD		Tom Lendacky <tom.lendacky@amd.com>
244  IBM
245  Intel		Tony Luck <tony.luck@intel.com>
246  Qualcomm	Trilok Soni <tsoni@codeaurora.org>
247
248  Microsoft	Sasha Levin <sashal@kernel.org>
249  VMware
250  Xen		Andrew Cooper <andrew.cooper3@citrix.com>
251
252  Canonical	Tyler Hicks <tyhicks@canonical.com>
253  Debian	Ben Hutchings <ben@decadent.org.uk>
254  Oracle	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
255  Red Hat	Josh Poimboeuf <jpoimboe@redhat.com>
256  SUSE		Jiri Kosina <jkosina@suse.cz>
257
258  Amazon
259  Google	Kees Cook <keescook@chromium.org>
260  ============= ========================================================
261
262If you want your organization to be added to the ambassadors list, please
263contact the hardware security team. The nominated ambassador has to
264understand and support our process fully and is ideally well connected in
265the Linux kernel community.
266
267Encrypted mailing-lists
268-----------------------
269
270We use encrypted mailing-lists for communication. The operating principle
271of these lists is that email sent to the list is encrypted either with the
272list's PGP key or with the list's S/MIME certificate. The mailing-list
273software decrypts the email and re-encrypts it individually for each
274subscriber with the subscriber's PGP key or S/MIME certificate. Details
275about the mailing-list software and the setup which is used to ensure the
276security of the lists and protection of the data can be found here:
277https://www.kernel.org/....
278
279List keys
280^^^^^^^^^
281
282For initial contact see :ref:`Contact`. For incident specific mailing-lists
283the key and S/MIME certificate are conveyed to the subscribers by email
284sent from the specific list.
285
286Subscription to incident specific lists
287^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
288
289Subscription is handled by the response teams. Disclosed parties who want
290to participate in the communication send a list of potential subscribers to
291the response team so the response team can validate subscription requests.
292
293Each subscriber needs to send a subscription request to the response team
294by email. The email must be signed with the subscriber's PGP key or S/MIME
295certificate. If a PGP key is used, it must be available from a public key
296server and is ideally connected to the Linux kernel's PGP web of trust. See
297also: https://www.kernel.org/signature.html.
298
299The response team verifies that the subscriber request is valid and adds
300the subscriber to the list. After subscription the subscriber will receive
301email from the mailing-list which is signed either with the list's PGP key
302or the list's S/MIME certificate. The subscriber's email client can extract
303the PGP key or the S/MIME certificate from the signature so the subscriber
304can send encrypted email to the list.
305
306