The 5.13-rc2 kernel prepatch is out fortesting. "The fixes here are all over the place - drivers, arch updates,documentation, tooling.. Nothing particularly stands out".
Group membership is normally used to grant access to some resource;examples might include using groups to control access to a shareddirectory, a printer, or the ability to use tools like sudo. Itis possible, though, to use group membership to deny access to aresource instead, and some administrators make use of that feature. Butgroups only work as a negative credential if the user cannot shed them atwill. Occasionally, some way to escape a group has turned up, resulting invulnerabilities on systems where they are used to block access; despitefixes in the past, it turns out that there is still a potential problemwith groups and user namespaces; thispatch set from Giuseppe Scrivano seeks to mitigate it through thecreation of "shadow" groups.
Greg Kroah-Hartman has announced the release of the 5.12.4, 5.11.21, 5.10.37, and 5.4.119 stable kernels. These are enormousupdates, with changes throughout the kernel tree; users should upgrade.
Security updates have been issued by Debian (jetty9, libgetdata, and postgresql-11), openSUSE (java-11-openjdk), SUSE (dtc, ibsim, ibutils, ipvsadm, and kernel), and Ubuntu (awstats and glibc).
The kernel's BPF virtual machine allowsprograms loaded from user space to be safely run in the kernel's context.That functionality would be of limited use, however, without the abilityfor those programs to interact with the rest of the kernel. The interfacebetween BPF and the kernel has been kept narrow for a number of goodreasons, including safety and keeping the kernel in control of the system.The 5.13 kernel, though, contains a feature that could, over time, widen that interface considerably: the ability to directly callkernel functions from BPF programs.
Security updates have been issued by Debian (graphviz and redmine), Fedora (dom4j, kernel, kernel-headers, kernel-tools, mariadb, php, php-phpmailer6, and redis), openSUSE (kernel and nagios), and Ubuntu (mysql-5.7, mysql-8.0 and python-django).
The discoverer of the KRACK attacksagainst WPA2 encryption in WiFi is back with a new set of flaws in thewireless-networking protocols. FragAttacks is a sizable group ofWiFi vulnerabilities that (ab)use the fragmentation and aggregation (thus"Frag") features of the standard. The fixes have been coordinated over anine-month period, which has allowed security researcher Mathy Vanhoef timeto create multiple papers, some slide decks, a demo video, patches, and, of course, a website and logo for the vulnerabilities.
GNU Guix, the transactional package manager and distribution, has releasedversion 1.3.0. This released adds new features, refines the userexperience, and improves performance. Support for the POWER9 platform isnow offered as technological preview.
Python in the browser has long been an item on the wish list of many in thePython community. At this point, though, JavaScript has well-cemented its role as thelanguage embedded into the web and its browsers. The Pyodide project provides away to run Python in the browser by compiling the existing CPythoninterpreter to WebAssembly andrunning that binary within the browser's JavaScript environment. Pyodidecame about as part of Mozilla's Iodideproject, which has fallen by the wayside, but Pyodide is now beingspunout as a community-driven project.
The Microsoft Open Source Blog takesa look at implementing eBPF support in Windows. "Although support for eBPF was first implemented in the Linux kernel, there has been increasing interest in allowing eBPF to be used on other operating systems and also to extend user-mode services and daemons in addition to just the kernel.Today we are excited to announce a new Microsoft open source project tomake eBPF work on Windows 10 and Windows Server 2016 and later. The ebpf-for-windows project aims to allow developers to use familiar eBPF toolchains and application programming interfaces (APIs) on top of existing versions of Windows. Building on the work of others, this project takes several existing eBPF open source projects and adds the “glue” to make them run on Windows."
The coreboot firmware project has releasedversion 4.14. "These changes have been all over the place, so that there's noparticular area to focus on when describing this release: We hadimprovements to mainboards, to chipsets (including much welcomedwork to open source implementations of what has been blobs before),to the overall architecture."
Security updates have been issued by Debian (hivex), Fedora (djvulibre and thunderbird), openSUSE (monitoring-plugins-smart and perl-Image-ExifTool), Oracle (kernel and kernel-container), Red Hat (kernel and kpatch-patch), SUSE (drbd-utils, java-11-openjdk, and python3), and Ubuntu (exiv2, firefox, libxstream-java, and pyyaml).
DragonFly BSD 6.0 has been released. "This version has a revamped VFS caching system, various filesystem updates including HAMMER2, and a long list of userland updates."
By the time the last pull request was acted on and 5.13-rc1was released, a total of 14,231 non-merge commits had found their way intothe mainline. That makes the 5.13 merge window larger than the entire 5.12development cycle (13,015 commits) and just short of all of 5.11 (14,340).In other words, 5.13 looks like one of the busier development cycles wehave seen for a little while.About 6,400 of these commits came in after thefirst-half summary was written, and they include a number ofsignificant new features.
The first 5.13 kernel prepatch is out fortesting, and the merge window is closed for this development cycle."This was - as expected - a fairly big merge window, but things seemto have proceeded fairly smoothly. Famous last words." In the end,14,231 non-merge changesets were pulled into the mainline during the mergewindow — more than were seen during the entire 5.12 cycle.
The IEEE, whose Symposium on Security and Privacy conference had acceptedthe "hypocrite commits" paper for publication, has posteda statement [PDF] on the episode.
While it is sometimes possible to perform I/O by moving data through theCPU, the only way to get the required level of performance is usually for devicesto move data directly to and from memory. Direct memory access (DMA) I/Ohas been well supported in the Linux kernel since the early days, but thereare always ways in which that support can be improved, especially whenhardware adds some challenges of its own. The somewhat confusingly named"non-contiguous" DMA API that was added for 5.13 shows the kinds of things that have to be done to getthe best performance on current systems.
New stable kernels 5.12.2, 5.11.19, 5.10.35, 5.4.117, and 4.19.190 have been released. They contain arelatively short list of updates throughout the tree; users of those seriesshould upgrade.
Security updates have been issued by Debian (mediawiki and unbound1.9), Fedora (djvulibre and samba), Mageia (ceph, messagelib, and pagure), openSUSE (alpine and exim), Oracle (kernel and postgresql), Scientific Linux (postgresql), and Ubuntu (thunderbird and unbound).
Among the many changes merged for 5.13 can be found performanceimprovements throughout the kernel. This work does not always stand outthe way that new features do, but it is vitally important for the future ofthe kernel overall. In the memory-management area, a couple oflong-running patch sets have finally made it into the mainline; theseprovide a bulk page-allocation interface andhuge-page mappings in the vmalloc() area.Both of these changes should make things faster, at least for someworkloads.
Security updates have been issued by Debian (python-django), Fedora (java-latest-openjdk, libopenmpt, python-yara, skopeo, thunderbird, and yara), openSUSE (ceph and openexr), Red Hat (postgresql), SUSE (libxml2), and Ubuntu (exim4 and gnome-autoar).
The era of tracking users all across the web using third-partycookies is coming to a close; that type of cookie issomething of a zombie at this point. All of the major browsers, saveone, are blocking third-party cookies by default and the holdout, GoogleChrome, plans to make that change next year. But Google, which has abusiness model built around advertising that benefits greatly from thestatus quo, has offered up an alternative scheme to "replace" third-partycookies. The Federated Learning ofCohorts (FLoC) is an in-browser mechanism to pigeonhole users in a waythat will be useful to advertisers, but the only reason the idea has anytraction at all is because it is being implemented in Chrome—the dominantbrowser today.
The Linux Foundation Technical Advisory Board has issued itsreport on the submission of (intentionally and unintentionally) buggy patches from theUniversity of Minnesota.
The movement toward using memory-safelanguages, and Rust in particular, has picked up a lot of steam over the past year or two. Removing thepossibility of buffer overflows, use-after-free bugs, and other woes associatedwith unmanaged pointers is an attractive feature, especially given thatthe majority of today's vulnerabilities stem from memory-safetyissues. On April 20, the Internet Security ResearchGroup (ISRG) announceda funding initiative targeting the Rustls TLS library in order toprepare it for more widespread adoption—including by ISRG's Let's Encrypt project.
Security updates have been issued by Debian (bind9, chromium, exim4, and subversion), Fedora (exiv2 and skopeo), openSUSE (gsoap), Oracle (bind, kernel, and sudo), SUSE (bind, ceph, ceph, deepsea, permissions, and stunnel), and Ubuntu (clamav, exim4, openvpn, python-django, and samba).
There are, it seems, 21 vulnerabilities in theExim email server that have been fixed in the 4.94.2 release; at least someof these are remotely exploitable for root access."The current Exim versions (and likely older versions too) suffer fromseveral exploitable vulnerabilities. These vulnerabilities were reportedby Qualys via security@exim.org back in October 2020.Due to several internal reasons it took more time than usual for the Eximdevelopment team to work on these reported issues in a timelymanner." See this advisoryfrom Qualys for the details.
The Red Hat Developer Blog has posted anintroduction to the rr debugger. "rr records trace informationabout the execution of an application. This information allows you torepeatedly replay a particular recording of a failure and examine it in theGNU Debugger (GDB) to better investigate the cause. In addition toreplaying the trace, rr lets you run the program in reverse, in essenceallowing you 'rewind the tape' to see what happened earlier in theexecution of the program."
The kernel's control-group mechanism existsto partition processes and to provide resource guarantees (and limits) for each. Processes runningwithin a properly configured control group are unable to deprivethose running in a different group of their allocated resources (CPU time,memory, I/O bandwidth, etc.), and are equally protected from interferenceby others. With few exceptions, control groups are not used to takedirect actions on processes; Christian Brauner's cgroup.killpatch set is meant to be one of those exceptions.
Security updates have been issued by CentOS (bind, GNOME, java-1.8.0-openjdk, java-11-openjdk, nss and nspr, xstream, and xterm), Debian (bind9 and libimage-exiftool-perl), Fedora (ansible, babel, java-11-openjdk, and java-latest-openjdk), Gentoo (chromium, clamav, firefox, git, grub, python, thunderbird, tiff, webkit-gtk, and xorg-server), Mageia (kernel, nvidia-current, nvidia390, qtbase5, and sdl2), openSUSE (Chromium, cifs-utils, cups, giflib, gsoap, libnettle, librsvg, netdata, postsrsd, samba, thunderbird, virtualbox, and webkit2gtk3), Red Hat (bind), Scientific Linux (bind), and SUSE (containerd, docker, runc and xen).
The 5.12.1,5.11.18,5.10.34, and5.4.116stable updates have been released. These are small and relativelyminor-seeming updates with the exception of 5.4.116, which contains asignificant set of BPF verifier fixes.
Version 6.0.0 ofthe QEMU hardware emulator is out. "This release contains 3300+commits from 268 authors." This release includes a lot of newemulations; see the announcement for a short list or the changelog for details.
As of this writing, just over 7,800 non-merge commits have been pulled intothe mainline repository for the 5.13 development cycle. It does indeedseem true that 5.13 will be busier than its predecessor was. The workmerged thus far affects subsystems across the kernel; read on for a summaryof what has been merged so far.
Security updates have been issued by Arch Linux (bind, chromium, firefox, gitlab, libupnp, nimble, opera, thunderbird, virtualbox, and vivaldi), Debian (composer, edk2, and libhibernate3-java), Fedora (java-1.8.0-openjdk, jetty, and samba), openSUSE (nim), Oracle (bind and runc), Red Hat (bind), SUSE (cifs-utils, cups, ldb, samba, permissions, samba, and tomcat), and Ubuntu (samba).
Martin Michlmayr has put together a primer on managing open-source projectsthrough their growth cycle, specifically with the help of a supportfoundation, and published the results as a67-page PDF file.
On April 20, the world became aware of aresearch program conducted out of the University of Minnesota (UMN) thatinvolved submitting intentionally buggy patches for inclusion into theLinux kernel. Since then, a paper resulting from this work has beenwithdrawn, various letters have gone back and forth, and numerous patches from UMN have beenaudited. It's clearly time for an update on the situation.
Security updates have been issued by Fedora (ceph, jetty, kernel, kernel-headers, kernel-tools, openvpn, and shim-unsigned-x64), Mageia (firefox and thunderbird), Oracle (nss and openldap), Red Hat (bind), Slackware (bind), SUSE (firefox, giflib, java-1_7_0-openjdk, libnettle, librsvg, thunderbird, and webkit2gtk3), and Ubuntu (bind9 and gst-plugins-good1.0).
The researchers at the University of Minnesota have posted adescription of the work they did [PDF] as part of their "hypocritecommits" project. It includes a list of the buggy commits they posted andhow they were handled.
Now that the Fedora 34 release is out the door, the Fedora project isturning its attention to Fedora 35, which is currently scheduledfor release on October 26. One of the changes under consideration forFedora 35 is thisproposal allowing maintainers to choose whether to build their packageswith GCC or Clang. This policy change may give maintainers some welcomeflexibility, but it has not proved entirely popular in the Fedoracommunity.
Stable kernels 5.11.17, 5.10.33, 5.4.115, 4.19.189, 4.14.232, 4.9.268, and 4.4.268 have been released. They all containimportant fixes and users should upgrade.
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