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Security updates have been issued by Arch Linux (couchdb), Debian (opensaml2 and shibboleth-sp2), Fedora (knot and knot-resolver), openSUSE (firefox), Slackware (libplist and mozilla), and Ubuntu (firefox and ipsec-tools).

Google has announced that it has released its container-diff tool under the Apache v2 license. "container-diff helps users investigate image changes by computing semantic diffs between images. What this means is that container-diff figures out on a low-level what data changed, and then combines this with an understanding of package manager information to output this information in a format that’s actually readable to users. The tool can find differences in system packages, language-level packages, and files in a container image.Users can specify images in several formats - from local Docker daemon (using the prefix `daemon://` on the image path), a remote registry (using the prefix `remote://`), or a file in the .tar in the format exported by "docker save" command. You can also combine these formats to compute the diff between a local version of an image and a remote version."

Observers of the kernel's commit stream or mailing lists will have seen acertain amount of traffic referring to the addition of SPDX licenseidentifiers to kernel source files. For many, this may be their first encounter with SPDX. Butthe SPDX effort has been going on for some years; this article describesSPDX, along with why and how the kernel community intends to use it.

Security updates have been issued by Arch Linux (firefox, flashplugin, lib32-flashplugin, and mediawiki), CentOS (kernel and php), Debian (firefox-esr, jackson-databind, and mediawiki), Fedora (apr, apr-util, chromium, compat-openssl10, firefox, ghostscript, hostapd, icu, ImageMagick, jackson-databind, krb5, lame, liblouis, nagios, nodejs, perl-Catalyst-Plugin-Static-Simple, php, php-PHPMailer, poppler, poppler-data, rubygem-ox, systemd, webkitgtk4, wget, wordpress, and xen), Mageia (flash-player-plugin, icu, jackson-databind, php, and roundcubemail), Oracle (kernel and php), Red Hat (openstack-aodh), SUSE (wget and xen), and Ubuntu (apport and webkit2gtk).

The LWN.net Weekly Edition for November 16, 2017 is available.

The NumPy project is phasingout support for Python 2. "The Python core team plans to stopsupporting Python 2 in 2020. The NumPy project has supported both Python 2and Python 3 in parallel since 2010, and has found that supporting Python 2is an increasing burden on our limited resources; thus, we plan toeventually drop Python 2 support as well. Now that we're entering the finalyears of community-supported Python 2, the NumPy project wants to clarifyour plans, with the goal of to helping our downstream ecosystem make plansand accomplish the transition with as little disruption aspossible." NumPy releases will fully support both Python 2 andPython 3 until December 31, 2018. New feature releases will support onlyPython 3 as of January 1, 2019. (Thanks to Nathaniel Smith)

After 16 years of evolution, the SciPy project has reached version 1.0. SciPy, a free-software project, has become one of the most popular computational toolkits for scientists from a wide range of disciplines, and is largely responsible for the ascendancy of Python in many areas of scientific research. While the 1.0 release is significant, much of the underlying software has been stable for some time; the "1.0" version number reflects that the project as a whole is on solid footing.

Stable kernels 4.13.13, 4.9.62, 4.4.98, and 3.18.81 have been released. They all containimportant fixes and users should upgrade.

Security updates have been issued by Debian (libxml-libxml-perl and varnish), openSUSE (GraphicsMagick, mongodb, shadowsocks-libev, and snack), Red Hat (flash-plugin, kernel, php, and redis), Scientific Linux (kernel and php), and Ubuntu (shadow).

Since the beginning, Linux has mapped the kernel's memory into the addressspace of every running process. There are solid performance reasons fordoing this, and the processor's memory-management unit can ordinarily betrusted to prevent user space from accessing that memory. More recently,though, some more subtle security issues related to this mapping have cometo light, leading to the rapid development of a new patch set that ends thislongstanding practice for the x86 architecture.

Firefox 57 has been released. From the releasenotes: "Brace yourself for an all-new Firefox. It’s fast. Reallyfast. It’s over twice as fast as Firefox from 6 months ago, built on acompletely overhauled core engine with brand new technology from ouradvanced research group, and graced with a clean, modern interface. Todayis the first of several releases we’re calling Firefox Quantum, alldesigned to get to the things you love and the stuff you need faster thanever before. Experience the difference on desktops running Windows, macOS,and Linux; on Android, speed improvements are landing as well, and bothAndroid and iOS have a new look and feel. To learn more about FirefoxQuantum, visit the Mozilla Blog."

On October 30, 2017, a groupof Czech researchers from Masaryk University presented the ROCA paperat the ACM CCS Conference, which earnedthe Real-World ImpactAward. We briefly mentioned ROCA whenit was first reported but haven't dug into details of the vulnerability yet. Because of itsfar-ranging impact, it seems important to review the vulnerability inlight of the new results published recently.

Security updates have been issued by Arch Linux (konversation), Debian (graphicsmagick and konversation), Fedora (git-annex, ImageMagick, kernel, and libgcrypt), Oracle (kernel), Red Hat (httpd), SUSE (firefox, nss), and Ubuntu (perl and postgresql-9.3, postgresql-9.5, postgresql-9.6).

The Fedora 27release is now available. "The Workstation edition of Fedora 27 features GNOME 3.26. In the new release, both the Display and Network configuration panels have been updated, along with the overall Settings panel appearance improvement. The system search now shows more results at once, including the system actions.GNOME 3.26 also features color emoji support, folder sharing in Boxes, andnumerous improvements in the Builder IDE tool."

The Netconf 2017,Part 2 and Netdev 2.2 conferences wererecently held in Seoul, South Korea. Netconf is an invitation-onlygathering of kernel networking developers, while Netdev is an open conference for the Linuxnetworking community. Attendees have put together reportsfrom all five days (two for Netconf and three for Netdev) that LWN ishappy to publish for them.

Red Hat has announceda version of its RHEL 7.4 distribution for the ARM64 architecture."Red Hat took a pragmatic approach to Arm servers by helping to driveopen standards and develop communities of customers, partners and a broadecosystem. Our goal was to develop a single operating platform acrossmultiple 64-bit ARMv8-A server-class SoCs from various suppliers whileusing the same sources to build user functionality and consistent featureset that enables customers to deploy across a range of serverimplementations while maintaining application compatibility." Moreinformation about what works at this point can be found in the release notes.

Security updates have been issued by Debian (graphicsmagick, imagemagick, mupdf, postgresql-common, ruby2.3, and wordpress), Fedora (tomcat), Gentoo (cacti, chromium, eGroupWare, hostapd, imagemagick, libXfont2, lxc, mariadb, vde, wget, and xorg-server), Mageia (flash-player-plugin and libjpeg), openSUSE (ansible, ImageMagick, java-1_8_0-openjdk, krb5, redis, shadow, virtualbox, and webkit2gtk3), Red Hat (rh-eclipse46-jackson-databind and rh-eclipse47-jackson-databind), SUSE (java-1_8_0-openjdk, mysql, openssl, and storm, storm-kit), and Ubuntu (perl).

The 4.14 kernel has been released after aten-week development cycle.Some of the most prominent features in this release includethe ORC unwinder for more reliabletracebacks and live patching,the long-awaited thread mode for controlgroups,support for AMD's secure memoryencryption,five-level page table support,a new zero-copy networking feature,the heterogeneous memory managementsubsystem,and more.See the Kernel Newbies 4.14page for more information.In the end, nearly 13,500 changesets were merged for 4.14, which is slatedto be the next long-term-support kernel.For the maintainers out there, it's worth noting Linus's warning that the4.15 merge window might be rather shorter than usual due to the USThanksgiving Holiday.

Kernel developers have worried for years that tracepoints could lead toapplications depending on obscure implementation details; the consequentneed to preserve existing behavior to avoid causing regressions could endup impeding future development. A recent report shows that theseccomp() system call is also more prone to regressions than usersmay expect — but kernel developers are unlikely to cause these regressionsand, indeed, have little ability to prevent them. Programs usingseccomp() will have an inherently higher risk of breaking whensoftware is updated.

Security updates have been issued by Arch Linux (lib32-openssl, libextractor, postgresql, and postgresql-old-upgrade), Debian (bchunk, postgresql-9.4, postgresql-9.6, postgresql-common, roundcube, and tomcat7), Gentoo (libxml2), SUSE (kvm, openssl1, and qemu), and Ubuntu (postgresql-common).

The Linux block layer provides an upstream interface to filesystems andblock-special devices allowing them to access a multitude of storagebackends in a uniform manner. It also provides downstream interfaces to devicedrivers and driver-support frameworks that allow those drivers andframeworks to receive requests in a manner most suitable to each. Somedrivers do not benefit from preliminary handling and just use the thin "biolayer" that we met previously. Otherdrivers benefitfrom some preprocessing that might detect batches of consecutive requests,may reorder requests based on various criteria, and which presents therequests as one or more well-defined streams. To service these drivers,there exists a section of the block layer that I refer to as the requestlayer.Subscribers can read on below for guest author Neil Brown's article thatwill appear in next week's edition.

Security updates have been issued by Debian (libpam4j, libreoffice, openssl, and ruby-yajl), Fedora (ansible), Mageia (openssl), SUSE (kernel), and Ubuntu (bind9).

Apple has let itbe known that the CUPS printing system will, as of version 2.3,switch from GPLv2 to the Apache License. This change is possible becauseApple requires that contributors sign acontributor agreement [PDF] giving joint ownership of any copyrights toApple.

The LWN.net Weekly Edition for November 9, 2017 is available.

The Free Software Foundation Europe (FSFE) has released thenext version of its REUSE practices,designed to make computers understand software copyrights and licenses."The REUSE practices help software developers make simple additions to license headers which make it easier for a computer to determine what license applies to the various parts of a programs source code. By following the REUSE practices, software developers can ensure their intent to license software under a particular license is understood and more readily adhered to."

The LiMux (or Limux)initiative in Munich has been heralded as an example of both the good andbad in moving a public administration away from proprietary systems. FreeSoftware Foundation Europe (FSFE) President Matthias Kirschner reviewed thehistory of the initiative—and its recent apparent downfall—in a talk atOpen Source Summit Europe in Prague. He also looked at the broaderimplications of the project as well as asking some questions thatfree-software advocates should consider moving forward.

Security updates have been issued by Arch Linux (chromium, libzip, and openssl), Debian (chromium-browser, otrs2, slurm-llnl, and tomcat7), Fedora (kernel, libgcrypt, nodejs, php, poppler, qemu, rpm, and wget), openSUSE (chromium), Red Hat (chromium-browser and rhvm-appliance), SUSE (krb5 and qemu), and Ubuntu (openjdk-8).

USBGuard is asecurity framework for the authorization of USB devices that can be pluggedinto a Linux system. For users who want to protect a system from maliciousUSB devices or unauthorized use of USB ports on a machine, this program gives a number of fine-grained policy options for specifyinghow USB devices can interact with a host system. It is a tool similar tousbauth, which also provides an interface to create access-control policies for theUSB ports. Although kernelauthorization for USB devices already exists, programs like USBGuard makeit easy to craft policies using those mechanisms.

The 2017 Maintainers Summit, the first event of its type, managed to cover awide range of topics in a single half-day. This article, which concludesLWN's coverage of this event, picks up a fewrelatively short topics that were discussed toward the end of the session.These include a new initiative to add SPDX license tags to the kernel, theperils of cross-subsystem development, and an evaluation of the summititself.

The4.13.12,4.9.61,4.4.97,and 3.18.80 stable kernel updates areavailable. As usual, each contains a long list of important fixes andupdates.

A traditional Kernel-Summit agenda item was a slot where Linus Torvalds hadthe opportunity to discuss the aspects of the development community that hewas (or, more often, was not) happy with. In 2017, this discussion movedto the smaller Maintainers Summit. Torvalds is mostly content with the state of thecommunity, it seems, but the group still found plenty of process-related things to talk about.

Security updates have been issued by Debian (apr, apr-util, chromium-browser, libpam4j, and mupdf), Fedora (community-mysql and modulemd), Mageia (git), openSUSE (libsass, libwpd, qemu, sssd, and SuSEfirewall2), Red Hat (Red Hat JBoss Enterprise Application Platform and Red Hat JBoss Enterprise Application Platform 7.0), SUSE (qemu), and Ubuntu (openssl).

Android has been a great boon to the kernel community, having brought agreat deal of growth in both the user and the development communities. ButAndroid has also been a problem in that devices running it ship withkernels containing large amounts (often millions of lines) of out-of-treecode. That fragments the development community and makes it impossible torun mainline kernels on this hardware. The problematic side of Android wasdiscussed at the 2017 Maintainer Summit; the picture that resulted issurprisingly optimistic.

Enlightenment DR 0.22.0 has been released. Thisversion of the desktop shell features improved Wayland support,improvements to new gadget infrastructure, a sudo/ssh askpass utility gui,tiling policy improvements, and integrated per-window volume controls,along with a switch to the Meson build system.

Laurent Pinchart ran a session at the 2017 Embedded Linux Conference Europeentitled "Bash the kernel maintainers"; the idea was to get feedback fromdevelopers on their experience working with the kernel community. A fewdays later, the Maintainers Summit held a free-flowing discussion on theissues that were brought up in that session. Some changes may result fromthis discussion, but it also showed how hard it can be to change how kernelsubsystem maintainers work.

The Software Freedom Law Center (SFLC) has responded to a recent blog post from the Software Freedom Conservancy (SFC) regarding the SFC's trademark. SFLC has asked the US Patent and Trademark Office (PTO) to cancel the SFC trademark due to a likelihood of confusion between the two marks; SFC posted about the action on its blog. Now, SFLC is telling its side of the story: "At the end of September, SFLC notified the US Patent and Trademark Office that we have an actual confusion problem caused by the trademark 'Software Freedom Conservancy,' which is confusingly similar to our own pre-existing trademark. US trademark law is all about preventing confusion among sources and suppliers of goods and services in the market. Trademark law acts to provide remedies against situations that create likelihood of, as well as actual, confusion. When you are a trademark holder, if a recent mark junior to yours causes likelihood of or actual confusion, you have a right to inform the PTO that the mark has issued in error, because that’s not supposed to happen. This act of notifying the PTO of a subsequently-issued mark that is causing actual confusion is called a petition to cancel the trademark. That’s not some more aggressive choice that the holder has made; it is not an attack, let alone a 'bizarre' attack, on anybody. That’s the name of the process by which the trademark holder gets the most basic value of the trademark, which is the right to abate confusion caused by the PTO itself."

The 2017Realtime Summit (RT-Summit) was hosted by the Czech Technical University onSaturday, October 21 in Prague, just before the Embedded LinuxConference. It was attended by more than 50 individuals with backgrounds ranging fromacademic to industrial, and some local students daring enough to spend a day with thatgroup. Guest author Mathieu Poirier provides summaries of some of thetalks from the summit.

Security updates have been issued by Arch Linux (curl, lib32-curl, lib32-libcurl-compat, lib32-libcurl-gnutls, libcurl-compat, libcurl-gnutls, libmupdf, mupdf, mupdf-gl, mupdf-tools, and zathura-pdf-mupdf), CentOS (liblouis), Debian (graphicsmagick, imagemagick, irssi, openssl, openssl1.0, redis, and wordpress), Mageia (lucene, poppler, and x11-server), SUSE (libwpd and webkit2gtk3), and Ubuntu (liblouis).

The tracking of kernel regressions was discussed at the 2017 Kernel Summit; the topicmade a second appearance at the first-ever Maintainers Summit two dayslater. This session was partly a repeat of what came before for thebenefit of those (including Linus Torvalds) who weren't at the firstdiscussion, but some new ground was covered as well.

The 4.14-rc8 kernel prepatch is out fortesting. "But to actually have decided that we don't need an rc8 this release,it would have had to be really totally quiet, and it wasn't. Nothinglooks scary, but we did have a few reverts in here still, and I'lljust feel happier giving 4.14 another final week... and I really hope that _will_ be the final week, and we don't findanything new scary." Along with the various fixes, this prepatchalso adds SPDX license tags to a lot of kernel source files.

Willy Tarreau reflectson his experience maintaining the 3.10 long-term kernel on the occasionof the release of the final update, 3.10.108."First, there's no such notion of 'important fixes'. Even seriousvendors employing several kernel developers got caught missing someapparently unimportant fixes and remaining vulnerable for more than twoyears after LTS was fixed. So you can imagine the level of quality you mayexpect from a $60 WiFi router vendor claiming to apply the samepractices... The reality is that a bug is a bug, and until it's exploitedit's not considered a vulnerability."

The GitLab open-source (and open-core) project hosting site has announced that it is moving away from its Contributor License Agreement (CLA) to a Developers Certificate of Origin (DCO), which is what is used by the Linux kernel, for example, to cover contributions made to its code base. "A Contributor License Agreement (CLA) is the industry standard for open source contributions to other projects, but it's unpopular with developers, who don't want to enter into legal terms and are put off by having to review a lengthy contract and potentially give up some of their rights. Contributors find the agreement unnecessarily restrictive, and it's deterring developers of open source projects from using GitLab. We were approached by Debian developers to consider dropping the CLA, and that's what we're doing." LWN looked at some of the background of this issue back in June.

The Software Freedom Conservancy (SFC) blog reveals a recent action taken by the Software Freedom Law Center (SFLC) to try to cancel the trademark for SFC. On September 22, SFLC filed a complaint with the US Patent and Trademark Office asking that the trademark be canceled because there is a likelihood of confusion between the trademarks:"Registrant's SOFTWARE FREEDOM CONSERVANCY Mark is confusingly similar toPetitioner's SOFTWARE FREEDOM LAW CENTER Mark." On November 2, SFC filed a response that lists the defenses it plans to use. From the blog post: "We are surprised and sad that our former attorneys, who kindly helped our organization start in our earliest days and later excitedly endorsed us when we moved from a volunteer organization to a staffed one, would seek to invalidate our trademark. Conservancy and SFLC are very different organizations and sometimes publicly disagree about detailed policy issues. Yet, both non-profits are charities organized to promote the public's interest. Thus, we are especially disappointed that SFLC would waste the precious resources of both organizations in this frivolous action."

Security updates have been issued by Debian (bchunk and openjdk-8), Fedora (kernel and seamonkey), Mageia (ansible, sdl2, sdl2_image, mingw, and tomcat), Oracle (kernel and liblouis), Red Hat (liblouis and samba), Scientific Linux (liblouis), Slackware (mariadb and openssl), and SUSE (ceph, kernel, and qemu).

Shuah Khan is the maintainer of the kernel's self-test subsystem. At the2017 Kernel Summit, she presented an update on the recent developments inkernel testing and led a related discussion. Much work has happened aroundself-testing in the kernel, but there remains a lot to be done.

The 4.13.11, 4.9.60, 4.4.96, and 3.18.79 stable kernels have been released byGreg Kroah-Hartman. There are, as usual, important fixes throughout thetree in these updates and users of those kernel series should upgrade.

Security updates have been issued by Debian (thunderbird), Fedora (glusterfs, gnome-shell, java-1.8.0-openjdk, lucene, openvpn, poppler, and xen), openSUSE (xen), and Ubuntu (libreoffice and samba).

The LWN.net Weekly Edition for November 2, 2017 is available.

On the Ubuntu Insights blog, Canonical has announced that it has joined the GNOME Foundation advisory board. "We hope to share the results of our many years of user research, testing plus the needs of our large and diverse user base to help map out the best way for the entire GNOME ecosystem to benefit from our membership.The GNOME community have been very welcoming to Ubuntu, and we are already seeing the fruits of their labour in 17.10. Night Light, Captive Portal detection, the new Control Center, and a host of new features are now available to Ubuntu Desktop users by default by way of the GNOME desktop.We look forward to working closely with the GNOME Foundation, and to many years of happy collaboration."

Much software that uses the Linux kernel does so at comparativearms-length: when it needs the kernel, perhaps for a read or write, itperforms a system call, then (at least from its point of view) continuesoperation later, with whatever the kernel chooses to give it in reply. Somesoftware, however, gets pretty intimately involved with the kernel as partof its normal operation, for example by using eBPF for low-level packetprocessing. Suricata is such a program; Eric Leblondspoke about it at Kernel Recipes 2017 in a talk entitled "eBPF and XDPseen from the eyes of a meerkat".