Merge branch 'jr/embargoed-releases-doc'

The role the security mailing list plays in an embargoed release
has been documented.

* jr/embargoed-releases-doc:
  embargoed releases: also describe the git-security list and the process

1 files changed, 140 insertions, 25 deletions

diff --git a/Documentation/howto/coordinate-embargoed-releases.txt b/Documentation/howto/coordinate-embargoed-releases.txt
index 601aae88e9a..e653775bab1 100644
--- a/Documentation/howto/coordinate-embargoed-releases.txt
+++ b/Documentation/howto/coordinate-embargoed-releases.txt
@@ -1,9 +1,10 @@
 Content-type: text/asciidoc
-Abstract: When a critical vulnerability is discovered and fixed, we follow this
- script to coordinate a public release.
+Abstract: When a vulnerability is reported, we follow these guidelines to
+ assess the vulnerability, create and review a fix, and coordinate embargoed
+ security releases.
 
 How we coordinate embargoed releases
-====================================
+------------------------------------
 
 To protect Git users from critical vulnerabilities, we do not just release
 fixed versions like regular maintenance releases. Instead, we coordinate
@@ -11,33 +12,147 @@ releases with packagers, keeping the fixes under an embargo until the release
 date. That way, users will have a chance to upgrade on that date, no matter
 what Operating System or distribution they run.
 
-Open a Security Advisory draft
-------------------------------
+The `git-security` mailing list
+-------------------------------
+
+Responsible disclosures of vulnerabilities, analysis, proposed fixes as
+well as the orchestration of coordinated embargoed releases all happen on the
+`git-security` mailing list at <git-security@googlegroups.com>.
+
+In this context, the term "embargo" refers to the time period that information
+about a vulnerability is kept under wraps and only shared on a need-to-know
+basis. This is necessary to protect Git's users from bad actors who would
+otherwise be made aware of attack vectors that could be exploited. "Lifting the
+embargo" refers to publishing the version that fixes the vulnerabilities.
+
+Audience of the `git-security` mailing list
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Anybody may contact the `git-security` mailing list by sending an email
+to <git-security@googlegroups.com>, though the archive is closed to the
+public and only accessible to subscribed members.
+
+There are a few dozen subscribed members: core Git developers who are trusted
+with addressing vulnerabilities, and stakeholders (i.e. owners of products
+affected by security vulnerabilities in Git).
+
+Most of the discussions revolve around assessing the severity of the reported
+issue (including the decision whether the report is security-relevant or can be
+redirected to the public mailing list), how to remediate the issue, determining
+the timeline of the disclosure as well as aligning priorities and
+requirements.
 
-The first step is to https://github.com/git/git/security/advisories/new[open an
-advisory]. Technically, it is not necessary, but it is convenient and saves a
-bit of hassle. This advisory can also be used to obtain the CVE number and it
-will give us a private fork associated with it that can be used to collaborate
-on a fix.
+Communications
+~~~~~~~~~~~~~~
 
-Release date of the embargoed version
--------------------------------------
+If you are a stakeholder, it is a good idea to pay close attention to the
+discussions, as pertinent information may be buried in the middle of a lively
+conversation that might not look relevant to your interests. For example, the
+tentative timeline might be agreed upon in the middle of discussing code
+comment formatting in one of the patches and whether or not to combine fixes
+for multiple, separate vulnerabilities into the same embargoed release. Most
+mail threads are not usually structured specifically to communicate
+agreements, assessments or timelines.
 
-If the vulnerability affects Windows users, we want to have our friends over at
-Visual Studio on board. This means we need to target a "Patch Tuesday" (i.e. a
-second Tuesday of the month), at the minimum three weeks from heads-up to
-coordinated release.
+Typical timeline
+----------------
 
-If the vulnerability affects the server side, or can benefit from scans on the
-server side (i.e. if `git fsck` can detect an attack), it is important to give
-all involved Git repository hosting sites enough time to scan all of those
-repositories.
+- A potential vulnerability is reported to the `git-security` mailing list.
+
+- The members of the git-security list start a discussion to give an initial
+  assessment of the severity of the reported potential vulnerability.
+  We aspire to do so within a few days.
+
+- After discussion, if consensus is reached that it is not critical enough
+  to warrant any embargo, the reporter is redirected to the public Git mailing
+  list. This ends the reporter's interaction with the `git-security` list.
+
+- If it is deemed critical enough for an embargo, ideas are presented on how to
+  address the vulnerability.
+
+- Usually around that time, the Git maintainer or their delegate(s) open a draft
+  security advisory in the `git/git` repository on GitHub (see below for more
+  details).
+
+- Code review can take place in a variety of different locations,
+  depending on context. These are: patches sent inline on the git-security list,
+  a private fork on GitHub associated with the draft security advisory, or the
+  git/cabal repository.
+
+- Contributors working on a fix should consider beginning by sending
+  patches to the git-security list (inline with the original thread), since they
+  are accessible to all subscribers, along with the original reporter.
+
+- Once the review has settled and everyone involved in the review agrees that
+  the patches are nearing the finish line, the Git maintainer, and others
+  determine a release date as well as the release trains that are serviced. The
+  decision regarding which versions need a backported fix is based on input from
+  the reporter, the contributor who worked on the patches, and from
+  stakeholders. Operators of hosting sites who may want to analyze whether the
+  given issue is exploited via any of the repositories they host, and binary
+  packagers who want to make sure their product gets patched adequately against
+  the vulnerability, for example, may want to give their input at this stage.
+
+- While the Git community does its best to accommodate the specific timeline
+  requests of the various binary packagers, the nature of the issue may preclude
+  a prolonged release schedule. For fixes deemed urgent, it may be in the best
+  interest of the Git users community to shorten the disclosure and release
+  timeline, and packagers may need to adapt accordingly.
+
+- Subsequently, branches with the fixes are pushed to the git/cabal repository.
+
+- The tags are created by the Git maintainer and pushed to the same repository.
+
+- The Git for Windows, Git for macOS, BSD, Debian, etc. maintainers prepare the
+  corresponding release artifacts, based on the tags created that have been
+  prepared by the Git maintainer.
+
+- The release artifacts prepared by various binary packagers can be
+  made available to stakeholders under embargo via a mail to the
+  `git-security` list.
+
+- Less than a week before the release, a mail with the relevant information is
+  sent to <distros@vs.openwall.org> (see below), a list used to pre-announce
+  embargoed releases of open source projects to the stakeholders of all major
+  distributions of Linux as well as other OSes.
+
+- Public communication is then prepared in advance of the release date. This
+  includes blog posts and mails to the Git and Git for Windows mailing lists.
+
+- On the day of the release, at around 10am Pacific Time, the Git maintainer
+  pushes the tag and the `master` branch to the public repository, then sends
+  out an announcement mail.
+
+- Once the tag is pushed, the Git for Windows maintainer publishes the
+  corresponding tag and creates a GitHub Release with the associated release
+  artifacts (Git for Windows installer, Portable Git, MinGit, etc).
+
+- Git for Windows release is then announced via a mail to the public Git and
+  Git for Windows mailing lists as well as via a tweet.
+
+- Ditto for distribution packagers for Linux and other platforms:
+  their releases are announced via their preferred channels.
+
+- A mail to <oss-security@lists.openwall.org> (see below for details) is sent
+  as a follow-up to the <distros@vs.openwall.org> one, describing the
+  vulnerability in detail, often including a proof of concept of an exploit.
+
+Note: The Git project makes no guarantees about timelines, but aims to keep
+embargoes reasonably short in the interest of keeping Git's users safe.
+
+Opening a Security Advisory draft
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The first step is to https://github.com/git/git/security/advisories/new[open
+an advisory]. Technically, this is not necessary. However, it is the most
+convenient way to obtain the CVE number and it give us a private repository
+associated with it that can be used to collaborate on a fix.
 
 Notifying the Linux distributions
----------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 At most two weeks before release date, we need to send a notification to
-distros@vs.openwall.org, preferably less than 7 days before the release date.
+<distros@vs.openwall.org>, preferably less than 7 days before the release date.
 This will reach most (all?) Linux distributions. See an example below, and the
 guidelines for this mailing list at
 https://oss-security.openwall.org/wiki/mailing-lists/distros#how-to-use-the-lists[here].
@@ -65,7 +180,7 @@ created using a command like this:
 	tar cJvf cve-xxx.bundle.tar.xz cve-xxx.bundle
 
 Example mail to distros@vs.openwall.org
----------------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ....
 To: distros@vs.openwall.org
@@ -101,7 +216,7 @@ Thanks,
 ....
 
 Example mail to oss-security@lists.openwall.com
------------------------------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 ....
 To: oss-security@lists.openwall.com
@@ -128,4 +243,4 @@ it goes to <developer>.
 
 Thanks,
 <name>
-....
+....
\ No newline at end of file