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