LWN.net

An unusual, some might say hostile, approach to disclosing an alleged remote-code-execution (RCE) flaw in the Forgejo software-collaboration platform has sparked a multifaceted conversation. A so-called "carrot disclosure" in April has raised questions about the researcher's methods of unveiling a security problem, Forgejo's security policies, and the project's overall security posture.

It seems that we are in for an extended period of the disclosure of vulnerabilities before fixes become available. One possible way of coping with this flood might be the killswitch proposal from Sasha Levin. In short, killswitch can immediately disable access to specific functionality in a running kernel, essentially blasting a vulnerable path (and its associated functionality) out of existence until a fix can be installed. "For most users, the cost of 'this socket family stops working for the day' is much smaller than the cost of running a known vulnerable kernel until the fix land."

The kernel's DAMON subsystem provides user-space monitoring and management of system memory. DAMON is developing rapidly, so an update on its progress has become a regular feature of the annual Linux Storage, Filesystem, Memory Management, and BPF Summit. This tradition continued at the 2026 gathering with an update from DAMON creator SeongJae Park covering a long list of new capabilities — tiering, data attributes monitoring, transparent huge pages, and more — being added to this subsystem.

Security updates have been issued by AlmaLinux (libsoup and mingw-libtiff), Debian (apache2, chromium, lcms2, libreoffice, and prosody), Fedora (openssl and perl-Starman), Oracle (git-lfs, libsoup, and perl-XML-Parser), Slackware (libgpg, mozilla, and php), SUSE (389-ds, cairo, cf-cli, chromedriver, cri-tools, freeipmi, gnutls, grafana, java-11-openjdk, java-17-openjdk, jetty-minimal, libmariadbd-devel, librsvg, mesa, mozjs52, mutt, nix, opencryptoki, python-Django, python-django, python-pytest, rmt-server, thunderbird, traefik, webkit2gtk3, wireshark, and xen), and Ubuntu (civicrm, dpkg, htmlunit, lcms2, libpng1.6, linux, linux-*, linux-azure, linux-azure-fips, linux-raspi, linux-xilinx, lua5.1, nasm, opam, openexr, openjpeg2, owslib, postfix, postfixadmin, and vim).

Greg Kroah-Hartman has announced the release of the 7.0.5, 6.18.28, 6.12.87, and 6.6.138 stable kernels. These kernels contain a partial fix for the Dirty Frag and Copy Fail 2 security flaws. Kroah-Hartman has confirmed that a second patch is required, but it is still in development and has not yet been merged.

Hyunwoo Kim has announced the Dirty Frag security flaw, a local-privilege-escalation (LPE) vulnerability similar to the recently disclosed Copy Fail flaw:

Because the embargo has now been broken, no patches or CVEs exist for these vulnerabilities. After consultation with the linux-distros@vs.openwall.org maintainers, and at the maintainers' request, I am publicly releasing this Dirty Frag document.

As with the previous Copy Fail vulnerability, Dirty Frag likewise allows immediate root privilege escalation on all major distributions.

Kim, who discovered the flaw and had attempted a coordinated disclosure set for May 12, has released the code for an exploit, as well as a example script to remove the vulnerable modules. A full write-up, with the disclosure timeline, is also available. It's unknown at this time whether this is an example of parallel discovery or how the third party was able to disclose it prior to the end of the embargo. We will be following up as more information comes to light.

On April 21, Andrew Morton let it be known that he intends to begin stepping away from the maintainership of kernel's memory-management subsystem — a responsibility he has carried since before memory management was even seen as its own subsystem. At the 2026 Linux Storage, Filesystem, Memory Management, and BPF Summit, one of the first sessions in the memory-management track was devoted to how the maintainership would be managed going forward. There are a lot of questions still to be answered.

Arjen Hiemstra has published an article on the status of the Union project: a single system to support all of KDE's technologies used for styling applications.

The work on Union's Breeze implementation has progressed to the point where it is very hard to distinguish whether or not you are running the Union version. We have also tested with a bunch of applications and made sure that any differences were fixed. So we are at a stage where we need to get Union into the hands of more people, both to get extra people testing whether there are any major issues, but also to have interested people creating new styles.

This means that with the upcoming Plasma 6.7 release, we plan to include Union. Discussion is currently ongoing whether we will enable it by default, but even if not there will be a way to try it out.

See Hiemstra's introductory article on Union, published in February 2025, for more about the project and its creation. KDE 6.7 is expected to be released in mid-June.

Security updates have been issued by AlmaLinux (dovecot, fence-agents, freeipmi, git-lfs, image-builder, kernel, libsoup, osbuild-composer, and python-tornado), Debian (apache2, libdatetime-timezone-perl, lrzip, tzdata, and wireshark), Fedora (dovecot, forgejo-runner, gh, gnutls, krb5, nano, pdns, pyOpenSSL, squid, vim, and xorg-x11-server-Xwayland), Mageia (graphicsmagick, kernel-linus, krb5-appl, libexif, libtiff, nano, nginx, ntfs-3g, opam, perl-Net-CIDR-Lite, perl-Starlet, perl-Starman, tcpflow, and virtualbox), Oracle (dovecot, fence-agents, freeipmi, image-builder, kernel, libcap, LibRaw, libsoup, openssh, osbuild-composer, python, python-tornado, python3, systemd, thunderbird, and tigervnc), SUSE (containerd, curl, erlang, flatpak, java-11-openjdk, java-21-openjdk, java-25-openjdk, liblxc-devel, libpng12, libthrift-0_23_0, openCryptoki, openexr, openssl-3, python3, python311-social-auth-core, rclone, skim, and thunderbird), and Ubuntu (apache2, coin3, editorconfig-core, insighttoolkit, linux, linux-aws, linux-aws-6.17, linux-gcp, linux-gcp-6.17, linux-hwe-6.17, linux-oracle, linux-realtime, linux-realtime-6.17, linux-azure, linux-azure-6.17, linux-oem-6.17, linux-azure-5.15, linux-gcp-6.8, nghttp2, python-dynaconf, slurm-wlm, swish-e, and webkit2gtk).

The 7.0.4, 6.18.27, and 6.12.86 stable kernels have been released; each contains another set of important fixes.

Inside this week's LWN.net Weekly Edition:

• Front: LLMs and security; restartable sequences and TCMalloc; Fedora and GNOME bug reports; Prolly trees; Arm on s390.
• Briefs: NHS open source; Alpine outage; GCC 16.1; Incus 7.0 LTS; NetHack 5.0.0; PHP license; Quotes; ...
• Announcements: Newsletters, conferences, security updates, patches, and more.

Predictions that LLM tools would cause a surge in reports of security vulnerabilities have, unquestionably, borne out. As expected, maintainers are having to wade through more security reports than ever before; in addition, LLM tools are disrupting traditional-coordinated disclosure practices as well. The method of Copy Fail's disclosure, in particular, left vendors, projects, and users scrambling. In addition, maintainers are seeing parallel discovery of the same security flaws within the embargo window. Both of these developments mean that coordinated security disclosures may become a thing of the past.

Version 7.0 of the Incus container and virtual-machine management system has been released. Notable changes in this release include the inclusion of a low-level backup API, the addition of basic S3 operations directly in Incus to replace the now-unmaintained MinIO project, as well as the removal of support for cgroups v1 and xtables (iptables/ip6tables/ebtables). This is a long-term-support (LTS) release, with support through June 2031.

The first 2 years will feature bug and security fixes as well as minor usability improvements, delivered through occasional point releases (7.0.x). After that initial two years, Incus 7.0 LTS will move to security only maintenance for the remaining of its 5 years of support.

A total of 204 individuals contributed to Incus between the 6.0 LTS and 7.0 LTS releases with 45 contributing between the 6.23 and 7.0 LTS releases.

Security updates have been issued by AlmaLinux (corosync, dovecot, image-builder, python-tornado, resource-agents, and systemd), Debian (openjdk-11, openjdk-17, and pyjwt), Fedora (pdns, pyOpenSSL, and squid), Slackware (hunspell), SUSE (alloy, avahi, bubblewrap, cmctl, coredns, curl, dpkg, firefox, golang-github-prometheus-prometheus, grafana, libpng12, PackageKit, sed, and xen), and Ubuntu (docker.io-app, nghttp2, python-django, and python-mako).

A recent patch set from Steffen Eiden and others has set the groundwork for allowing hardware-assisted emulation of Arm CPUs on s390 CPUs. Version two of the posting fixes a handful of smaller problems, but does not differ much. The patches were welcomed by the Arm maintainers, pending some discussion of how the collaboration between the architectures could be structured to prevent maintainability problems on the Arm side. When those details are resolved, the patches could pave the way for transparently running Arm-based virtual machines (VMs) on s390 hosts at native or near-native speeds.