1 .. _embargoed_hardware_issues:
2
3 Embargoed hardware issues
4 =========================
5
6 Scope
7 -----
8
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
11 kernel.
12
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 silicon vendors, hardware integrators, and other parties. For some of the
17 issues, software mitigations can depend on microcode or firmware updates,
18 which need further coordination.
19
20 .. _Contact:
21
22 Contact
23 -------
24
25 The Linux kernel hardware security team is separate from the regular Linux
26 kernel security team.
27
28 The team only handles developing fixes for 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.
33
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 coordinate a fix
36 according to our documented process.
37
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
41 the following URLs:
42
43 - PGP: https://www.kernel.org/static/files/hardware-security.asc
44 - S/MIME: https://www.kernel.org/static/files/hardware-security.crt
45
46 While hardware security issues are often handled by the affected silicon
47 vendor, we welcome contact from researchers or individuals who have
48 identified a potential hardware flaw.
49
50 Hardware security officers
51 ^^^^^^^^^^^^^^^^^^^^^^^^^^
52
53 The current team of hardware security officers:
54
55 - Linus Torvalds (Linux Foundation Fellow)
56 - Greg Kroah-Hartman (Linux Foundation Fellow)
57 - Thomas Gleixner (Linux Foundation Fellow)
58
59 Operation of mailing-lists
60 ^^^^^^^^^^^^^^^^^^^^^^^^^^
61
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's infrastructure.
69
70 The Linux Foundation's current director of IT Project infrastructure is
71 Konstantin Ryabitsev.
72
73
74 Non-disclosure agreements
75 -------------------------
76
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.
81
82
83 Memorandum of Understanding
84 ---------------------------
85
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, silicon vendors, and other parties.
89
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.
93
94 The Linux kernel community has a dedicated hardware security team for
95 initial contact, which oversees the process of handling such issues under
96 embargo rules.
97
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.
102
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 else becomes aware of a potential violation, please report it
111 immediately to the Hardware security officers.
112
113
114 Process
115 ^^^^^^^
116
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.
123
124 Start of Disclosure
125 """""""""""""""""""
126
127 Disclosure starts by emailing the Linux kernel hardware security team per
128 the Contact section above. This initial contact should contain a
129 description of the problem and a list of any known affected silicon. If
130 your organization builds or distributes the affected hardware, we encourage
131 you to also consider what other hardware could be affected. The disclosing
132 party is responsible for contacting the affected silicon vendors in a
133 timely manner.
134
135 The hardware security team will provide an incident-specific encrypted
136 mailing list which will be used for initial discussion with the reporter,
137 further disclosure, and coordination of fixes.
138
139 The hardware security team will provide the disclosing party a list of
140 developers (domain experts) who should be informed initially about the
141 issue after confirming with the developers that they will adhere to this
142 Memorandum of Understanding and the documented process. These developers
143 form the initial response team and will be responsible for handling the
144 issue after initial contact. The hardware security team is supporting the
145 response team, but is not necessarily involved in the mitigation
146 development process.
147
148 While individual developers might be covered by a non-disclosure agreement
149 via their employer, they cannot enter individual non-disclosure agreements
150 in their role as Linux kernel developers. They will, however, agree to
151 adhere to this documented process and the Memorandum of Understanding.
152
153 The disclosing party should provide a list of contacts for all other
154 entities who have already been, or should be, informed about the issue.
155 This serves several purposes:
156
157 - The list of disclosed entities allows communication across the
158 industry, e.g. other OS vendors, HW vendors, etc.
159
160 - The disclosed entities can be contacted to name experts who should
161 participate in the mitigation development.
162
163 - If an expert who is required to handle an issue is employed by a listed
164 entity or member of an listed entity, then the response teams can
165 request the disclosure of that expert from that entity. This ensures
166 that the expert is also part of the entity's response team.
167
168 Disclosure
169 """"""""""
170
171 The disclosing party provides detailed information to the initial response
172 team via the specific encrypted mailing-list.
173
174 From our experience, the technical documentation of these issues is usually
175 a sufficient starting point, and further technical clarification is best
176 done via email.
177
178 Mitigation development
179 """"""""""""""""""""""
180
181 The initial response team sets up an encrypted mailing-list or repurposes
182 an existing one if appropriate.
183
184 Using a mailing list is close to the normal Linux development process and
185 has been successfully used to develop mitigations for various hardware
186 security issues in the past.
187
188 The mailing list operates in the same way as normal Linux development.
189 Patches are posted, discussed, and reviewed and if agreed upon, applied to
190 a non-public git repository which is only accessible to the participating
191 developers via a secure connection. The repository contains the main
192 development branch against the mainline kernel and backport branches for
193 stable kernel versions as necessary.
194
195 The initial response team will identify further experts from the Linux
196 kernel developer community as needed. Any involved party can suggest
197 further experts to be included, each of which will be subject to the same
198 requirements outlined above.
199
200 Bringing in experts can happen at any time in the development process and
201 needs to be handled in a timely manner.
202
203 If an expert is employed by or a member of an entity on the disclosure list
204 provided by the disclosing party, then participation will be requested from
205 the relevant entity.
206
207 If not, then the disclosing party will be informed about the experts'
208 participation. The experts are covered by the Memorandum of Understanding
209 and the disclosing party is requested to acknowledge their participation.
210 In the case where the disclosing party has a compelling reason to object,
211 any objection must to be raised within five working days and resolved with
212 the incident team immediately. If the disclosing party does not react
213 within five working days this is taken as silent acknowledgment.
214
215 After the incident team acknowledges or resolves an objection, the expert
216 is disclosed and brought into the development process.
217
218 List participants may not communicate about the issue outside of the
219 private mailing list. List participants may not use any shared resources
220 (e.g. employer build farms, CI systems, etc) when working on patches.
221
222 Early access
223 """"""""""""
224
225 The patches discussed and developed on the list can neither be distributed
226 to any individual who is not a member of the response team nor to any other
227 organization.
228
229 To allow the affected silicon vendors to work with their internal teams and
230 industry partners on testing, validation, and logistics, the following
231 exception is provided:
232
233 Designated representatives of the affected silicon vendors are
234 allowed to hand over the patches at any time to the silicon
235 vendor’s response team. The representative must notify the kernel
236 response team about the handover. The affected silicon vendor must
237 have and maintain their own documented security process for any
238 patches shared with their response team that is consistent with
239 this policy.
240
241 The silicon vendor’s response team can distribute these patches to
242 their industry partners and to their internal teams under the
243 silicon vendor’s documented security process. Feedback from the
244 industry partners goes back to the silicon vendor and is
245 communicated by the silicon vendor to the kernel response team.
246
247 The handover to the silicon vendor’s response team removes any
248 responsibility or liability from the kernel response team regarding
249 premature disclosure, which happens due to the involvement of the
250 silicon vendor’s internal teams or industry partners. The silicon
251 vendor guarantees this release of liability by agreeing to this
252 process.
253
254 Coordinated release
255 """""""""""""""""""
256
257 The involved parties will negotiate the date and time when the embargo
258 ends. At that point, the prepared mitigations are published into the
259 relevant kernel trees. There is no pre-notification process: the
260 mitigations are published in public and available to everyone at the same
261 time.
262
263 While we understand that hardware security issues need coordinated embargo
264 time, the embargo time should be constrained to the minimum time that is
265 required for all involved parties to develop, test, and prepare their
266 mitigations. Extending embargo time artificially to meet conference talk
267 dates or other non-technical reasons creates more work and burden for the
268 involved developers and response teams as the patches need to be kept up to
269 date in order to follow the ongoing upstream kernel development, which
270 might create conflicting changes.
271
272 CVE assignment
273 """"""""""""""
274
275 Neither the hardware security team nor the initial response team assign
276 CVEs, nor are CVEs required for the development process. If CVEs are
277 provided by the disclosing party they can be used for documentation
278 purposes.
279
280 Process ambassadors
281 -------------------
282
283 For assistance with this process we have established ambassadors in various
284 organizations, who can answer questions about or provide guidance on the
285 reporting process and further handling. Ambassadors are not involved in the
286 disclosure of a particular issue, unless requested by a response team or by
287 an involved disclosed party. The current ambassadors list:
288
289 ============= ========================================================
290 AMD Tom Lendacky <thomas.lendacky@amd.com>
291 Ampere Darren Hart <darren@os.amperecomputing.com>
292 ARM Catalin Marinas <catalin.marinas@arm.com>
293 IBM Power Michael Ellerman <ellerman@au.ibm.com>
294 IBM Z Christian Borntraeger <borntraeger@de.ibm.com>
295 Intel Tony Luck <tony.luck@intel.com>
296 Qualcomm Trilok Soni <quic_tsoni@quicinc.com>
297 RISC-V Palmer Dabbelt <palmer@dabbelt.com>
298 Samsung Javier González <javier.gonz@samsung.com>
299
300 Microsoft James Morris <jamorris@linux.microsoft.com>
301 Xen Andrew Cooper <andrew.cooper3@citrix.com>
302
303 Canonical John Johansen <john.johansen@canonical.com>
304 Debian Ben Hutchings <ben@decadent.org.uk>
305 Oracle Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
306 Red Hat Josh Poimboeuf <jpoimboe@redhat.com>
307 SUSE Jiri Kosina <jkosina@suse.cz>
308
309 Google Kees Cook <keescook@chromium.org>
310
311 LLVM Nick Desaulniers <ndesaulniers@google.com>
312 ============= ========================================================
313
314 If you want your organization to be added to the ambassadors list, please
315 contact the hardware security team. The nominated ambassador has to
316 understand and support our process fully and is ideally well-connected in
317 the Linux kernel community.
318
319 Encrypted mailing-lists
320 -----------------------
321
322 We use encrypted mailing lists for communication. The operating principle
323 of these lists is that email sent to the list is encrypted either with the
324 list's PGP key or with the list's S/MIME certificate. The mailing list
325 software decrypts the email and re-encrypts it individually for each
326 subscriber with the subscriber's PGP key or S/MIME certificate. Details
327 about the mailing list software and the setup that is used to ensure the
328 security of the lists and protection of the data can be found here:
329 https://korg.wiki.kernel.org/userdoc/remail.
330
331 List keys
332 ^^^^^^^^^
333
334 For initial contact see the :ref:`Contact` section above. For incident
335 specific mailing lists, the key and S/MIME certificate are conveyed to the
336 subscribers by email sent from the specific list.
337
338 Subscription to incident-specific lists
339 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
340
341 Subscription to incident-specific lists is handled by the response teams.
342 Disclosed parties who want to participate in the communication send a list
343 of potential experts to the response team so the response team can validate
344 subscription requests.
345
346 Each subscriber needs to send a subscription request to the response team
347 by email. The email must be signed with the subscriber's PGP key or S/MIME
348 certificate. If a PGP key is used, it must be available from a public key
349 server and is ideally connected to the Linux kernel's PGP web of trust. See
350 also: https://www.kernel.org/signature.html.
351
352 The response team verifies that the subscriber request is valid and adds
353 the subscriber to the list. After subscription the subscriber will receive
354 email from the mailing-list which is signed either with the list's PGP key
355 or the list's S/MIME certificate. The subscriber's email client can extract
356 the PGP key or the S/MIME certificate from the signature so the subscriber
357 can send encrypted email to the list.
358
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