<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><h1 style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="font-weight: normal; font-size: 12px;" class=""><font face="HelveticaNeue" class="">Hello compiler enthusiasts,</font></span></h1><font face="HelveticaNeue" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><div class=""><font face="HelveticaNeue" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br class=""></span></font></div>The Apple LLVM team would like to propose that a new a security process and an associated private LLVM Security Group be created under the umbrella of the LLVM project.</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">A draft proposal for how we could organize such a group and what its process could be is </span></font><a href="https://reviews.llvm.org/D70326" class="">available on Phabricator</a><font face="HelveticaNeue" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">. The proposal starts with a list of goals for the process and Security Group, repeated here:</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">The LLVM Security Group has the following goals:</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""></font><ol style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><li class=""><font face="HelveticaNeue" class="">Allow LLVM contributors and security researchers to disclose security-related issues affecting the LLVM project to members of the LLVM community.</font></li><li class=""><font face="HelveticaNeue" class="">Organize fixes, code reviews, and release management for said issues.</font></li><li class=""><font face="HelveticaNeue" class="">Allow distributors time to investigate and deploy fixes before wide dissemination of vulnerabilities or mitigation shortcomings.</font></li><li class=""><font face="HelveticaNeue" class="">Ensure timely notification and release to vendors who package and distribute LLVM-based toolchains and projects.</font></li><li class=""><font face="HelveticaNeue" class="">Ensure timely notification to users of LLVM-based toolchains whose compiled code is security-sensitive, through <a href="https://cve.mitre.org/" class="">the CVE process</a>.</font></li></ol><font face="HelveticaNeue" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">We’re looking for answers to the following questions:</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""></font><ol style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><li class=""><font face="HelveticaNeue" class=""><u class="">On this list</u>: Should we create a security group and process?</font></li><li class=""><font face="HelveticaNeue" class=""><u class="">On this list</u>: Do you agree with the goals listed in the proposal?</font></li><li class=""><font face="HelveticaNeue" class=""><u class="">On this list</u>: at a high-level, what do you think should be done differently, and what do you think is exactly right in the draft proposal?</font></li><li class=""><font face="HelveticaNeue" class=""><u class="">On the Phabricator code review</u>: going into specific details, what do you think should be done differently, and what do you think is exactly right in the draft proposal?</font></li><li class=""><font face="HelveticaNeue" class=""><u class="">On this list</u>: to help understand where you’re coming from with your feedback, it would be helpful to state how you personally approach this issue:</font></li><ol class=""><li class=""><font face="HelveticaNeue" class="">Are you an LLVM contributor (individual or representing a company)?</font></li><li class=""><font face="HelveticaNeue" class="">Are you involved with security aspects of LLVM (if so, which)?</font></li><li class=""><font face="HelveticaNeue" class="">Do you maintain significant downstream LLVM changes?</font></li><li class=""><font face="HelveticaNeue" class="">Do you package and deploy LLVM for others to use (if so, to how many people)?</font></li><li class=""><font face="HelveticaNeue" class="">Is your LLVM distribution based on the open-source releases?</font></li><li class=""><font face="HelveticaNeue" class="">How often do you usually deploy LLVM?</font></li><li class=""><font face="HelveticaNeue" class="">How fast can you deploy an update?</font></li><li class=""><font face="HelveticaNeue" class="">Does your LLVM distribution handle untrusted inputs, and what kind?</font></li><li class=""><font face="HelveticaNeue" class="">What’s the threat model for your LLVM distribution?</font></li></ol></ol><font face="HelveticaNeue" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">Other open-source projects have security-related groups and processes. They structure their group very differently from one another. This proposal borrows from some of these projects’ processes. A few examples:</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""></font><ul style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><li class=""><a href="https://webkit.org/security-policy/" class=""><font face="HelveticaNeue" class="">https://webkit.org/security-policy/</font></a></li><li class=""><a href="https://chromium.googlesource.com/chromium/src/+/lkgr/docs/security/faq.md" class=""><font face="HelveticaNeue" class="">https://chromium.googlesource.com/chromium/src/+/lkgr/docs/security/faq.md</font></a></li><li class=""><a href="https://wiki.mozilla.org/Security" class=""><font face="HelveticaNeue" class="">https://wiki.mozilla.org/Security</font></a></li><li class=""><a href="https://www.openbsd.org/security.html" class=""><font face="HelveticaNeue" class="">https://www.openbsd.org/security.html</font></a></li><li class=""><a href="https://security-team.debian.org/security_tracker.html" class=""><font face="HelveticaNeue" class="">https://security-team.debian.org/security_tracker.html</font></a></li><li class=""><a href="https://www.python.org/news/security/" class=""><font face="HelveticaNeue" class="">https://www.python.org/news/security/</font></a></li></ul><font face="HelveticaNeue" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">When providing feedback, it would be great to hear if you’ve dealt with these or other projects’ processes, what works well, and what can be done better.</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">I’ll go first in answering my own questions above:</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""></font><ol style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><li class=""><font face="HelveticaNeue" class="">Yes! We should create a security group and process.</font></li><li class=""><font face="HelveticaNeue" class="">We agree with the goals listed.</font></li><li class=""><font face="HelveticaNeue" class="">We think the proposal is exactly right, but would like to hear the community’s opinions.</font></li><li class=""><font face="HelveticaNeue" class="">Here’s how we approach the security of LLVM:</font></li><ol class=""><li class=""><font face="HelveticaNeue" class="">I contribute to LLVM as an Apple employee.</font></li><li class=""><font face="HelveticaNeue" class="">I’ve been involved in a variety of LLVM security issues, from automatic variable initialization to security-related diagnostics, as well as deploying these mitigations to internal codebases.</font></li><li class=""><font face="HelveticaNeue" class="">We maintain significant downstream changes.</font></li><li class=""><font face="HelveticaNeue" class="">We package and deploy LLVM, both internally and externally, for a variety of purposes, including the clang, Swift, and mobile GPU shader compilers.</font></li><li class=""><font face="HelveticaNeue" class="">Our LLVM distribution is not directly derived from the open-source release. In all cases, all non-upstream public patches for our releases are available in repository branches at <a href="https://github.com/apple" class="">https://github.com/apple</a>.</font></li><li class=""><font face="HelveticaNeue" class="">We have many deployments of LLVM whose release schedules vary significantly. The LLVM build deployed as part of Xcode historically has one major release per year, followed by roughly one minor release every 2 months. Other releases of LLVM are also security-sensitive and don’t follow the same schedule.</font></li><li class=""><font face="HelveticaNeue" class="">This depends on which release of LLVM is affected.</font></li><li class=""><font face="HelveticaNeue" class="">Yes, our distribution sometimes handles untrusted input.</font></li><li class=""><font face="HelveticaNeue" class="">The threat model is highly variable depending on the particular language front-ends being considered.</font></li></ol></ol><font face="HelveticaNeue" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">Apple is involved with a variety of open-source projects and their disclosures. For example, we frequently work with the WebKit community to handle security issues through their process.</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">Thanks,</span><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class="">JF</span></font><br style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><div class=""><font face="HelveticaNeue" class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);" class=""><br class=""></span></font></div></body></html>