Vue normale

Stenberg: The pressure

Par : corbet
26 mai 2026 à 13:40
Curl maintainer Daniel Stenberg writes about the stress of keeping up with the current flood of security reports.

This is a never-before seen or experienced pressure on the curl project and its security team members. An avalanche of high priority work that trumps all other things in the project that is primarily mental because we certainly could ignore them all if we wanted, but we feel a responsibility, we have a conscience and we are proud about our work. We feel obliged to fix security problems in the software we have helped shipped to every device on the globe. This is personal to us.

With about half the release cycle left until the pending release ships, we already have twelve confirmed vulnerabilities meaning twelve pending CVE announcements. That's a new project record and it also means we will reach thirty published CVEs in 2026 even before half the calendar year has passed. The projected total amount of curl CVEs published through the whole year is therefore at least double this number!

[$] Better automatic management of transparent huge pages

Par : corbet
26 mai 2026 à 13:23
Huge pages can improve performance by increasing translation lookaside buffer (TLB) utilization and reducing memory-management overhead. Transparent huge pages (THPs) are supposed to make huge-page usage, well, transparent, Nico Pache said at the beginning of his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit. That transparency has never worked as well as many would like; he has been working on improvements to make it easier for applications to use huge pages on Linux systems. A following session, led by David Hildenbrand, was focused on how THPs could be taken away from processes that are not using them fully.

[$] Tier-aware memory-controller limits

Par : corbet
25 mai 2026 à 15:03
Joshua Hahn began his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit by saying that the memory controller for control groups is intended to provide resource allocation, accounting, and protection from interference by other tasks. But it was not really designed for tiered-memory systems; he is looking for a way to improve that situation.

Kernel prepatch 7.1-rc5

Par : corbet
24 mai 2026 à 22:59
The 7.1-rc5 kernel prepatch is out for testing. Quoth Linus:

I'm not entirely happy about it - most of this is totally trivial stuff to random drivers, which obviously makes it all less scary, but at the same time I'm really not convinced the churn is worth it at rc5 time. These things are "fixes", sure, but at the same time a lot of them are simply so irrelevant that I think they'd be better off in a linux-next tree and get merged during the merge window.

So I think I'll start being a bit more hardnosed about this kind of unnecessary churn this late in the game. We are supposed to look for *regressions*. Non-critical fixes to long-standing issues are simply not appropriate for this late in the release cycle.

End result: this is too big, and this is the heads-up that I'll be pushing back on pointless pull requests with fixes that just aren't that important. And yes, several of these series were triggered by AI code review.

[$] Custom page-cache policies with BPF

Par : corbet
22 mai 2026 à 14:37
The kernel's page cache is charged with maintaining pages (or, more correctly, folios) containing copies of data from files in the filesystem; its performance has a big effect on the performance of the system as a whole. One of the key decisions the kernel must make is when to evict folios from the page cache. At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Tal Zussman ran a memory-management-track session on how the page cache could be better customized for specific workloads. It will not be much of a spoiler to say that it involves BPF.

[$] Toward better handling of major page faults

Par : corbet
22 mai 2026 à 13:50
A major page fault occurs when a process attempts to access a page that is not currently present in RAM; satisfying such faults usually involves I/O, and can thus take some time. When many threads sharing an address space are generating page faults, the result can be significant lock contention while that I/O takes place. During the memory-management track at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Barry Song led a session to try, yet again, to find an enduring solution to this problem.

Security updates for Friday

Par : corbet
22 mai 2026 à 13:07
Security updates have been issued by AlmaLinux (firefox), Debian (chromium, nss, openvpn, and thunderbird), Fedora (cockpit, kernel, and linux-firmware), Oracle (gdk-pixbuf2, kernel, and libsndfile), SUSE (container-suseconnect, cpp-httplib, dnsmasq, firefox, glibc, GraphicsMagick, java-1_8_0-openj9, kernel, mozjs115, php8, python-urllib3, rekor, rootlesskit, rsync, tiff, ucode-intel, util-linux, and xz), and Ubuntu (bind9, bubblewrap, libarchive, linux-intel-iot-realtime, postgresql-14, postgresql-16, postgresql-17, postgresql-18, and xdg-desktop-portal).

Vulnerabilities in various GTK-based PDF readers

Par : corbet
21 mai 2026 à 21:05
Michael Catanzaro has disclosed a command-injection vulnerability affecting a number of GTK-based PDF readers; exploits included:

They contain a script for building malicious polyglot PDFs that are simultaneously both valid PDF files and also valid ELF binaries. When the user opens the PDF in the PDF viewer and clicks on a malicious link embedded in the PDF, the PDF abuses the command injection vulnerability to load itself as a GTK module using the `--gtk-module` command line flag. It can then execute arbitrary code via its library constructor. That flag was removed in GTK 4, which is why the vulnerability is much less serious for Papers than it is for Evince, Atril, and Xreader.

OpenBSD 7.9 released

Par : corbet
21 mai 2026 à 14:27
The OpenBSD 7.9 release is out, right on schedule. There is the usual long list of new features, including improved architecture support, CPU scheduling on heterogeneous systems, the ability to hibernate a suspended system after a configurable delay, socket splicing, a __pledge_open() system call giving special access to the C library, and much more. See the announcement and the full changelog for details.

[$] Support for private memory nodes

Par : corbet
21 mai 2026 à 13:22
Gregory Price started his session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit by saying that, in current kernels, if a NUMA node has memory, the assumption is that anybody can make use of it. He is trying to implement the opposite policy — to make some memory off-limits for all processes except those designed specifically to use it. The session was used to present his goals and to discuss how they might be implemented.

Security updates for Thursday

Par : corbet
21 mai 2026 à 13:19
Security updates have been issued by AlmaLinux (kernel, kernel-rt, and libsndfile), Debian (bind9, evince, firefox-esr, openjpeg2, pdns, and rsync), Fedora (erlang-cowlib, evince, expat, firefox, kernel, mingw-expat, mysql8.0, mysql8.4, nss, opencryptoki, pgadmin4, proftpd, python-django5, python-django6, python-dotenv, rsync, rust-nu, rustup, and strongswan), Oracle (nginx, nginx:1.24, ruby, ruby:3.3, and squid), Slackware (bind and rsync), SUSE (buildah, distribution, distribution-registry, docker, firefox-esr, helm, libpainter0, libsdb2_4_2, postgresql-jdbc, runc, and vim), and Ubuntu (gnutls28, gst-plugins-good1.0, jq, linux-nvidia, linux-nvidia-lowlatency, openvpn, rsync, and unbound).

[$] What is to be done about MGLRU?

Par : corbet
20 mai 2026 à 13:14
"Reclaim" is the task of finding memory that can be taken away from its current user and put to better uses within the system; it is a core part of the memory-management picture. The addition of the multi-generational LRU (MGLRU) was meant to provide a better reclaim implementation than the "traditional LRU" that preceded it, but MGLRU has complicated the situation instead. No fewer than three memory-management-track sessions at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit were focused on MGLRU, with an eye toward integrating it more fully, improving its performance, and addressing some problems encountered with Android systems.

Security updates for Wednesday

Par : corbet
20 mai 2026 à 13:04
Security updates have been issued by AlmaLinux (kernel, libpng, nginx, nginx:1.24, ruby, and ruby:3.3), Debian (gnutls28 and linux-6.1), Fedora (dnsmasq, kernel, keylime-agent-rust, perl-Net-CIDR-Lite, python-pysam, python-urllib3, rust-cargo-vendor-filterer, rust-ingredients, rust-oo7-cli, rust-rpki, rust-sevctl, and rust-tealdeer), Mageia (bind), Oracle (bind, giflib, gimp:2.8, kernel, libpng, rsync, ruby, and vim), Slackware (haveged and mozilla), SUSE (cockpit, dnsmasq, erlang26, freeipmi, git-bug, glibc, GraphicsMagick, haveged, ImageMagick, iproute2, kernel, openssh, perl-CryptX, perl-HTTP-Tiny, postgresql14, postgresql15, postgresql16, python-Pillow, rsync, tiff, and traefik), and Ubuntu (Highlight.js, linux, linux-aws, linux-aws-5.15, linux-aws-fips, linux-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-nvidia, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-oracle, linux-raspi, linux-realtime, linux, linux-aws, linux-aws-fips, linux-bluefield, linux-fips, linux-gcp, linux-gcp-5.4, linux-gcp-fips, linux-ibm, linux-ibm-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-xilinx-zynqmp, linux, linux-aws, linux-aws-fips, linux-fips, linux-gcp-4.15, linux-gcp-fips, linux-kvm, linux-oracle, linux, linux-aws, linux-aws-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-ibm-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-raspi, linux-raspi-realtime, linux-realtime, linux-realtime-6.8, linux, linux-aws, linux-hwe-6.17, linux-oem-6.17, linux-oracle, linux-raspi, linux-realtime, linux-realtime-6.17, and smarty3).

Firefox 151.0 released

Par : corbet
19 mai 2026 à 16:10
Version 151.0 of the Firefox browser has been released. Significant changes include the ability to clear and restart a private-browsing session, better fingerprinting protection, control over the apparent location when using the Firefox VPN, and more.

[$] In search of faster this_cpu operations

Par : corbet
19 mai 2026 à 14:30
The kernel's this_cpu operations are meant to speed access to per-CPU variables. They are more optimal on some CPUs than others, though. During a memory-management-track session at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, Yang Shi proposed a fundamental, and somewhat controversial, change to how these operations work in order to provide better performance on a wider range of architectures.

[$] What's brewing in CXL

Par : corbet
19 mai 2026 à 14:15
Compute Express Link (CXL) is a technology intended to enable the provision of "memory nodes" in data centers that provide (possibly shared) memory to nearby CPUs. It has, Dan Williams said at the beginning of his memory-management-track session on the topic at the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, "been making memory-management problems worse since 2021". He used the session to provide an overview of the ways in which CXL can be expected to extend that record into the future.

[$] Improving the per-CPU memory allocator

Par : corbet
19 mai 2026 à 13:27
There are many places in the kernel where performance can be improved by using per-CPU data. But, as it turns out, the kernel's allocator for per-CPU data has some performance problems of its own. Harry Yoo led a session in the memory-management track of the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit to explore ways to address those problems and accelerate the allocation and initialization of per-CPU data.

Security updates for Tuesday

Par : corbet
19 mai 2026 à 13:24
Security updates have been issued by AlmaLinux (libpng and nginx), Debian (erlang, netatalk, and nginx), Fedora (mod_md and SDL2_image), Mageia (perl-libwww-perl, perl-HTTP-Message, perl-WWW-Mechanize-Cached, perl-File-XDG, perl-Path-Tiny, perl-YAML-Syck, postgresql15, and rclone), SUSE (agama, alloy, cacti, cloud-init, dnsmasq, emacs, firefox, glibc, go1.25, go1.26, google-cloud-sap-agent, google-guest-agent, ibus-rime, librime, imagemagick, kernel, libsndfile, nginx, ongres-scram, ongres-stringprep, plexus-testing,, openexr, openssh, PackageKit, perl-Text-CSV_XS, php-composer2, php8, postgresql16, postgresql18, python-lxml, python-python-multipart, python3, python311-urllib3, rmt-server, rsync, tiff, tree-sitter, util-linux, and xen), and Ubuntu (linux, linux-aws, linux-aws-5.4, linux-aws-fips, linux-azure, linux-azure-5.4, linux-azure-fips, linux-bluefield, linux-fips, linux-gcp, linux-gcp-5.4, linux-gcp-fips, linux-hwe-5.4, linux-ibm, linux-ibm-5.4, linux-iot, linux-kvm, linux-oracle, linux-oracle-5.4, linux-xilinx-zynqmp, linux, linux-aws, linux-kvm, linux-lts-xenial, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-raspi, and linux-xilinx-zynqmp).
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