Episode Details

AsiaBSDcon review, Meltdown and Spectre Patches in FreeBSD stable, Interview with MidnightBSD founder, 8 months with TrueOS, mysteries of GNU and BSD split

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Headlines

AsiaBSDCon 2018 has concluded

• We have just returned from AsiaBSDCon in Tokyo, Japan last weekend
• Please excuse our jetlag
• The conference consisted two days of meeting followed by 2 days of paper presentations
• We arrived a few days early to see some sights and take a few extra delicious meals in Tokyo
• The first day of meetings was a FreeBSD developer summit (while Benedict was teaching his two tutorials) where we discussed the FreeBSD release cycle and our thoughts on improving it, the new Casper capsicum helper service, and developments in SDIO which will eventually enable WiFi and SD card readers on more embedded devices
• The second day of meetings consisted of bhyvecon, a miniconf that covered development in all hypervisors on all BSDs. It also included presentations on the porting of bhyve to IllumOS.
• Then the conference started
• There were a number of great presentations, plus an amazing hallway track as usual
• It was great to see many old friends and to spend time discussing the latest happenings in BSD. A couple of people came by and asked to take a picture with us and we were happy to do that. ***

FreeBSD releases Spectre and Meltdown mitigations for 11.1

Speculative execution vulnerability mitigation is a work in progress. This advisory addresses the most significant issues for FreeBSD 11.1 on amd64 CPUs. We expect to update this advisory to include 10.x for amd64 CPUs. Future FreeBSD releases will address this issue on i386 and other CPUs. freebsd-update will include changes on i386 as part of this update due to common code changes shared between amd64 and i386, however it contains no functional changes for i386 (in particular, it does not mitigate the issue on i386).
Many modern processors have implementation issues that allow unprivileged attackers to bypass user-kernel or inter-process memory access restrictions by exploiting speculative execution and shared resources (for example, caches).
An attacker may be able to read secret data from the kernel or from a process when executing untrusted code (for example, in a web browser).

• Meltdown: The mitigation is known as Page Table Isolation (PTI). PTI largely separates kernel and user mode page tables, so that even during speculative execution most of the kernel's data is unmapped and not accessible. A demonstration of the Meltdown vulnerability is available at https://github.com/dag-erling/meltdown. A positive result is definitive (that is, the vulnerability exists with certainty). A negative result indicates either that the CPU is not affected, or that the test is not capable of demonstrating the issue on the CPU (and may need to be modified). A patched kernel will automatically enable PTI on Intel CPUs. The status can be checked via the vm.pmap.pti sysctl PTI introduces a performance regression. The observed performance loss is significant in microbenchmarks of system call overhead, but is much smalle