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Security updates for Tuesday

Par :corbet
29 avril 2025 à 12:04
Security updates have been issued by AlmaLinux (glibc, php:8.1, and thunderbird), Debian (libreoffice), Fedora (caddy), Mageia (chromium-browser-stable), Red Hat (php:8.1), SUSE (glow), and Ubuntu (kicad, linux-aws-5.15, linux-azure-nvidia, linux-gcp-5.15, mistral, python-mistral-lib, tomcat8, and trafficserver).

Signing key change for Kali Linux

Par :corbet
29 avril 2025 à 12:05
The Kali Linux distribution has announced that software updates will soon start failing for all users:

This is not only you, this is for everyone, and this is entirely our fault. We lost access to the signing key of the repository, so we had to create a new one. At the same time, we froze the repository (you might have noticed that there was no update since Friday 18th), so nobody was impacted yet. But we're going to unfreeze the repository this week, and it's now signed with the new key.

The announcement includes instructions for how to recover from the problem.

[$] Cache awareness for the CPU scheduler

Par :corbet
29 avril 2025 à 12:30
The kernel's CPU scheduler has to balance a wide range of objectives. The tasks in the system must be scheduled fairly, with latency for any given task kept within bounds. All of the CPUs in the system should be kept busy if there is enough work to do, but unneeded CPUs should be shut down to reduce power consumption. A task should also run on the CPU that is most likely to have cached the memory that task is using. This patch series from Chen Yu aims to improve how the scheduler handles cache locality for multi-threaded processes.

Barnes: Parallel ./configure

Par :corbet
29 avril 2025 à 13:46
Tavian Barnes takes on the tedious process of waiting for configure scripts to run.

I paid good money for my 24 CPU cores, but ./configure can only manage to use 69% of one of them. As a result, this random project takes about 13.5× longer to configure the build than it does to actually do the build.

The purpose of a ./configure script is basically to run the compiler a bunch of times and check which runs succeeded. In this way it can test whether particular headers, functions, struct fields, etc. exist, which lets people write portable software. This is an embarrassingly parallel problem, but Autoconf can't parallelize it, and neither can CMake, neither can Meson, etc., etc.

(Thanks to Paul Wise).

LWN's Mastodon migration

Par :corbet
29 avril 2025 à 19:29
The LWN.net fediverse (Mastodon) feed has moved; we are now known as @LWN@lwn.net. The migration magic has shifted many of our followers over automatically but, if you follow that stream, you might want to make sure that you have shifted to the new source.

How LWN is faring in 2025

Par :corbet
30 avril 2025 à 14:37
Just over six months ago, The Economist described the US economy as "the envy of the world". That headline would be unlikely to appear now. The economic boom referenced in that article feels like a distant memory, markets are falling, and uncertainty is at an all-time high. Like everybody else, LWN is affected by the current turbulence in the political and economic spheres; we expect to get through this period, but there will be some challenges.

The conclusion of the FSF board review

Par :corbet
30 avril 2025 à 15:42
The Free Software Foundation has announced the completion of the review of its board of directors; the process resulted in the reconfirmation of all five sitting board members.

The review examined board members Ian Kelling, Geoffrey Knauth, Henry Poole, Richard Stallman, and Gerald Sussman. The process generated detailed philosophical and policy discussions between board members and the FSF's global associate members on topics ranging from the firmness of the Free Software Definition, developments in machine learning, to the board's president position.

Albertson: Future of OSL in Jeopardy

Par :corbet
30 avril 2025 à 20:06
Lance Albertson writes that the Oregon State University Open Source Lab, the home of many prominent free-software projects over the years, has run into financial trouble:

I am writing to inform you about a critical and time-sensitive situation facing the Open Source Lab. Over the past several years, we have been operating at a deficit due to a decline in corporate donations. While OSU's College of Engineering (CoE) has generously filled this gap, recent changes in university funding have led to a significant reduction in CoE's budget. As a result, our current funding model is no longer sustainable and CoE needs to find ways to cut programs.

Earlier this week, I was informed that unless we secure $250,000 in committed funds, the OSL will be forced to shut down later this year.

[$] LWN.net Weekly Edition for May 1, 2025

Par :corbet
1 mai 2025 à 00:19
Inside this week's LWN.net Weekly Edition:

  • Front: Mailman 2 vulnerabilities; AI in Debian; __nonstring__; Cache-aware scheduling; Freezing filesystems; Socket-level storage; Debugging information; LWN in 2025.
  • Briefs: Debian election; Kali Linux key; OpenBSD 7.7; Firefox 138.0; GCC 15.1; Meson 1.8.0; Valgrind 3.25.0; FSF review; OSI retrospective; Mastodon; Quotes; ...
  • Announcements: Newsletters, conferences, security updates, patches, and more.

[$] Custom out-of-memory killers in BPF

Par :corbet
1 mai 2025 à 13:51
The out-of-memory (OOM) killer has long been a scary and controversial part of the Linux kernel. It is summoned from some dark place when the system as a whole (or, more recently, any given control group) is running so low on memory that further allocations are not possible; its job is to kill off processes until a sufficient amount of memory has been freed. Roman Gushchin has found a way to make the OOM killer even scarier: adding the ability to load custom OOM killers in BPF.

[$] Injecting speculation barriers into BPF programs

Par :corbet
5 mai 2025 à 19:04
The disclosure of the Spectre class of hardware vulnerabilities created a lot of pain for kernel developers (and many others). That pain was especially acutely felt in the BPF community. While an attacker might have to painfully search the kernel code base for exploitable code, an attacker using BPF can simply write and load their own speculation gadgets, which is a much more efficient way of operating. The BPF community reacted by, among other things, disallowing the loading of programs that may include speculation gadgets. Luis Gerhorst would like to change that situation with this patch series that takes a more direct approach to the problem.

A new AUTOSEL release

Par :corbet
6 mai 2025 à 08:11
AUTOSEL is a tool that is used to find kernel patches that should be considered for backporting into the stable releases. Sasha Levin has announced a new and completely rewritten version of AUTOSEL for those who would like to play with it.

Unlike the previous version that relied on word statistics and older neural network techniques, AUTOSEL leverages modern large language models and embedding technology to provide significantly more accurate recommendations.

Security updates for Tuesday

Par :corbet
6 mai 2025 à 10:18
Security updates have been issued by Fedora (chromium and kappanhang), Red Hat (osbuild-composer and thunderbird), SUSE (chromedriver), and Ubuntu (c-ares, corosync, mysql-8.0, mysql-8.4, openjdk-17, openjdk-21, openjdk-24, openjdk-8, and openjdk-lts).

The end of the USENIX Annual Technical Conference

Par :corbet
7 mai 2025 à 07:37
On the 50th anniversary of the USENIX organization, its flagship Annual Technical Conference (ATC) is coming to an end.

For the past two decades, as more USENIX conferences have joined the USENIX calendar by focusing on specific topics that grew out of ATC itself, attendance at ATC has steadily decreased to the point where there is no longer a critical mass of researchers and practitioners joining us. Thus, after many years of experiments to adapt this conference to the ever-changing tech landscape and community, the USENIX Board of Directors has made the difficult decision to sunset USENIX ATC.

Many important technologies first saw the light of day at this event.

The state of SSL stacks

Par :corbet
7 mai 2025 à 08:20
Willy Tarreau and William Lallemand have posted an extensive white paper examining the landscape of the available SSL implementations.

OpenSSL 3.0 performs significantly worse than alternative SSL libraries, forcing organizations to provision more hardware just to maintain existing throughput. This raises important questions about performance, energy efficiency, and operational costs.

Examining alternatives—BoringSSL, LibreSSL, WolfSSL, and AWS-LC—reveals a landscape of trade-offs. Each offers different approaches to API compatibility, performance optimization, and QUIC support. For developers navigating the modern SSL ecosystem, understanding these trade-offs is crucial for optimizing performance, maintaining compatibility, and future-proofing their infrastructure.

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