Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 358 insertions, 0 deletions

diff --git a/Documentation/process/embargoed-hardware-issues.rst b/Documentation/process/embargoed-hardware-issues.rst
new file mode 100644
index 000000000..d07f16c3c
--- /dev/null
+++ b/Documentation/process/embargoed-hardware-issues.rst
@@ -0,0 +1,358 @@
+.. _embargoed_hardware_issues:
+
+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,
+silicon vendors, hardware integrators, 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 developing fixes for 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 <hardware-security@kernel.org>. This
+is a private list of security officers who will help you coordinate a fix
+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
+the following URLs:
+
+  - PGP: https://www.kernel.org/static/files/hardware-security.asc
+  - S/MIME: https://www.kernel.org/static/files/hardware-security.crt
+
+While hardware security issues are often handled by the affected silicon
+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, members
+of Linux Foundation's IT operations personnel technically have the
+ability to access the embargoed information, but are obliged to
+confidentiality by their employment contract. Linux Foundation IT
+personnel are also responsible for operating and managing the rest of
+kernel.org's infrastructure.
+
+The Linux Foundation's current director of IT Project infrastructure 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, silicon 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 else 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 emailing the Linux kernel hardware security team per
+the Contact section above.  This initial contact should contain a
+description of the problem and a list of any known affected silicon. If
+your organization builds or distributes the affected hardware, we encourage
+you to also consider what other hardware could be affected.  The disclosing
+party is responsible for contacting the affected silicon vendors in a
+timely manner.
+
+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 of fixes.
+
+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.
+
+The disclosing party should provide a list of contacts for all other
+entities who have already been, or should be, informed about the issue.
+This serves several purposes:
+
+ - The list of disclosed entities allows communication across the
+   industry, e.g. other OS vendors, HW vendors, etc.
+
+ - The disclosed entities can be contacted to name experts who should
+   participate in the mitigation development.
+
+ - If an expert who is required to handle an issue is employed by a listed
+   entity or member of an listed entity, then the response teams can
+   request the disclosure of that expert from that entity. This ensures
+   that the expert is also part of the entity's response team.
+
+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.
+
+Using a mailing list is close to the normal Linux development process and
+has been successfully used to develop 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 upon, 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.  Any involved party can suggest
+further experts to be included, each of which will be subject to the same
+requirements outlined above.
+
+Bringing in experts can happen at any time in the development process and
+needs to be handled in a timely manner.
+
+If an expert is employed by or a member of an entity on the disclosure list
+provided by the disclosing party, then participation will be requested from
+the relevant entity.
+
+If not, then the disclosing party will be informed about the experts'
+participation. The experts are covered by the Memorandum of Understanding
+and the disclosing party is requested to acknowledge their participation.
+In the case where the disclosing party has a compelling reason to object,
+any objection must to be raised within five working days and resolved with
+the incident team immediately. If the disclosing party does not react
+within five working days this is taken as silent acknowledgment.
+
+After the incident team acknowledges or resolves an objection, the expert
+is disclosed and brought into the development process.
+
+List participants may not communicate about the issue outside of the
+private mailing list. List participants may not use any shared resources
+(e.g. employer build farms, CI systems, etc) when working on patches.
+
+Early access
+""""""""""""
+
+The patches discussed and developed on the list can neither be distributed
+to any individual who is not a member of the response team nor to any other
+organization.
+
+To allow the affected silicon vendors to work with their internal teams and
+industry partners on testing, validation, and logistics, the following
+exception is provided:
+
+	Designated representatives of the affected silicon vendors are
+	allowed to hand over the patches at any time to the silicon
+	vendor’s response team. The representative must notify the kernel
+	response team about the handover. The affected silicon vendor must
+	have and maintain their own documented security process for any
+	patches shared with their response team that is consistent with
+	this policy.
+
+	The silicon vendor’s response team can distribute these patches to
+	their industry partners and to their internal teams under the
+	silicon vendor’s documented security process. Feedback from the
+	industry partners goes back to the silicon vendor and is
+	communicated by the silicon vendor to the kernel response team.
+
+	The handover to the silicon vendor’s response team removes any
+	responsibility or liability from the kernel response team regarding
+	premature disclosure, which happens due to the involvement of the
+	silicon vendor’s internal teams or industry partners. The silicon
+	vendor guarantees this release of liability by agreeing to this
+	process.
+
+Coordinated release
+"""""""""""""""""""
+
+The involved parties will negotiate the date and time when the embargo
+ends. At that point, the prepared mitigations are published into the
+relevant kernel trees.  There is no pre-notification process: the
+mitigations are published in public and available to everyone at the same
+time.
+
+While we understand that hardware security issues need coordinated embargo
+time, the embargo time should be constrained to the minimum time that is
+required for all involved parties to develop, test, and prepare their
+mitigations. Extending embargo time artificially to meet conference talk
+dates or other non-technical reasons creates 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:
+
+  ============= ========================================================
+  AMD		Tom Lendacky <thomas.lendacky@amd.com>
+  Ampere	Darren Hart <darren@os.amperecomputing.com>
+  ARM		Catalin Marinas <catalin.marinas@arm.com>
+  IBM Power	Madhavan Srinivasan <maddy@linux.ibm.com>
+  IBM Z		Christian Borntraeger <borntraeger@de.ibm.com>
+  Intel		Tony Luck <tony.luck@intel.com>
+  Qualcomm	Trilok Soni <quic_tsoni@quicinc.com>
+  RISC-V	Palmer Dabbelt <palmer@dabbelt.com>
+  Samsung	Javier González <javier.gonz@samsung.com>
+
+  Microsoft	James Morris <jamorris@linux.microsoft.com>
+  Xen		Andrew Cooper <andrew.cooper3@citrix.com>
+
+  Canonical	John Johansen <john.johansen@canonical.com>
+  Debian	Ben Hutchings <ben@decadent.org.uk>
+  Oracle	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+  Red Hat	Josh Poimboeuf <jpoimboe@redhat.com>
+  SUSE		Jiri Kosina <jkosina@suse.cz>
+
+  Google	Kees Cook <keescook@chromium.org>
+
+  LLVM		Nick Desaulniers <ndesaulniers@google.com>
+  ============= ========================================================
+
+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 that is used to ensure the
+security of the lists and protection of the data can be found here:
+https://korg.wiki.kernel.org/userdoc/remail.
+
+List keys
+^^^^^^^^^
+
+For initial contact see the :ref:`Contact` section above. 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 to incident-specific lists is handled by the response teams.
+Disclosed parties who want to participate in the communication send a list
+of potential experts 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.
+