LSS/OSS NA 2018

| categories: fedora

Last week was Open Source Summit and Linux Security Summit in beautiful Vancouver, BC. Highlights:

  • There was a talk on security in Zephyr and Fuchsia. While the focus of the conference is Linux, there's a growing interest in running Linux in conjunction with processors running other operating systems. Zephyr is an open source RTOS targeted at processors with a smaller footprint than Linux. Most of the security improvements have been adding features to take advantage of the MMU/MPU. One of those features was userspace support, which is always a bit of a surprise to hear as a new feature. Fuchsia is Google's new microkernel operating system. There's some argument that microkernels offer more security than Linux since more parts can run in userspace. Much of the talk was about the resource and namespace model. There's been a good deal of work put into this but it was noted much of this is still likely to be reworked.

  • Kees Cook talked about how to make C less dangerous. I've seen bits and pieces of this talk before and LWN did a great writeup so I won't rehash it all. This did spawn a thread about how exactly VLAs are or aren't security issues.

  • Someone from Microsoft talked about Azure Sphere. Azure Sphere is Microsoft's attempt at an IoT based microprocessor that runs Linux. The real challenge is that the device has 4MB. The talk focused on what kinds of optimizations they had to do to get it to run in that space. There's been similar attempts before but 4MB is still incredibly impressive. I'll be keeping an eye out when the patches go upstream (and maybe buy a device).

  • Two people from the Android security team at Google gave a talk about the state of things there. Much of the talk was numbers was numbers and statistics. Standard recommendations such as "reduce your attack surface" and "use SELinux" are very effective at reducing the severity of bugs. Bounds checks were a very common root cause. It turns out, copy_*_user APIs are easy to get wrong. Features such as CONFIG_HARDENED_USERCOPY are very effective here (there was an all too familiar story about "well if I turn on hardened usercopy my tests don't pass"). The Android security team does great work and it's good to see the data.

  • Alexander Popov gave a talk on his experience in upstreaming the stackleak plugin. This is a gcc plugin that's designed to clear the stack after every system call to reduce the chance of information leak. The talk covered the history of development from separating the plugin from grsecurity to its current form. Like many stories of contributing, this one was not easy. It took many iterations and has been dismissed by Linus. As of this writing it still hasn't been pulled in and I hope it gets taken in soon.

  • Greg KH ~~generated headlines~~ talked about Spectre and Meltdown response in the kernel. The most interesting part of the talk was outlining the time frame of when various parts got fixed. Also important was the discussion of stable kernels and pointing out that backporting is a huge pain.

  • Sasha Levin and Julia Lawall talked about using machine learning on stable trees. The current system for getting fixes into stable trees relies on a combination of maintainers and developers realizing a fix should go in. This leads to many fixes that could be useful not actually making it in. The new idea is to use machine learning to figure out what patches might be appropriate for stable. Like all machine learning work, it's not perfect but it's found a number of patches. Sasha has also done a lot of analysis on the stable trees and buggy patches (it turns out patches that come later in the -rc cycle are more likely to be buggy) so this work is overall beneficial to the kernel. I for one welcome our new bot maintainers.

  • Julia Cartwright talked about the state of the RT patches. These patches have been out of tree for a very long time and have been slowly getting merged. The good news is there may be a light at the end of the tunnel thanks to a renewed effort. The current patch set is a manageable size and the current work can be explained in a few slides. She also mentioned the RT group can always use more people to get involved for anyone who is interested in fun projects.

  • Casey Schaufler discussed the trade offs in kernel hardening. Security is often a trade off for some other aspect of system performance (speed, memory). Security is also harder to quantify vs. "it goes 20% faster". Casey talked about some examples similar to Kees of APIs that need to be corrected and problems with getting things merged. Ultimately, we are going to have to figure out how to make security work.

  • Amye Scarvada gave a talk about "rebooting a project" but it was really a short workshop on a method of how to do planning. The target audience was community managers but I found it really useful for any project. She talked about things like short and near term goals and determining external vs internal and technical vs non techcnical problems. Really helpful for framing problems.

  • Jim Perrin talked about making a move from engineering to management. I've seen various people talk about this before and the most important point to remember is that management is not a "promotion", it is a different track and set of skills than engineering. You need to learn and develop those skills. He gave some good examples of what he had to figure out and learn. He emphasized that you should not go into management unless you really want to. Once again, really good advice.

  • There was a panel discussion about writing for your career. All the the panelists work in open source and writing in some fashion and encouraged everyone to write. Much of the discussion was about how to work with professional editors and common pitfalls people make when writing. Having a clear point to your writing is important and makes writing easier (something I've certainly found when trying to blog). You also don't write a book to get rich. I appreciated the insight from all the panelists and have some more ideas for my own writing.

A big thank you to the organizers for giving me a chance to look at actual penguins