LWN.net

The persistent-memory arrays we're told we'll all be able to get somedaypromise high-speed, byte-addressable storage in massive quantities. TheLinux kernel community has been working to support thistechnology fully for a few years now, but there is one problem lacking a propersolution: allowing direct writes to persistent memory that is managed by afilesystem. None of the proposed solutions have yet madeit into the mainline, but that hasn't stopped developers from trying; nowtwo new patch sets addressing this issue are under consideration.

The release of the 2017 version of TeX Live had plenty of incrementalimprovements for the TeXcomputer typesetting system and the myriad of tools that go with it. Oneof the more significant changes, though, was the release of the 1.0.4version of LuaTeX, which allows users to embed Lua programs into their TeXdocuments. That ability allows creating non-standard and unusualtypesetting effects much more easily than it would be with TeX itself.Guest author Lee Phillips gives an overview of LuaTeX and shows some of thethings that can be accomplished using it.

Version 3.6.0 of the GnuTls TLS library is out. For details on thisrelease, see this overview."In short, this release introduces a new lock-free random generatorand adds new TLS extensions shared by both TLS 1.2 and 1.3, such as FiniteField Diffie Hellman negotiation, Ed25519 and RSA-PSS signatures. Theseadditions modernize the current TLS 1.2 support and pave the way for TLS1.3 support in the library. Furthermore, tlsfuzzer is introduced in ourcontinuous integration test suite. Tlsfuzzer, is a meticulous TLS testsuite, which tests the behavior of the implementation on various corner(and not) cases, and acts complementary to the internal GnuTLS test suiteand its unit testing."

Security updates have been issued by Debian (extplorer and libraw), Fedora (mingw-libsoup, python-tablib, ruby, and subversion), Mageia (avidemux, clamav, nasm, php-pear-CAS, and shutter), Oracle (xmlsec1), Red Hat (openssl tomcat), Scientific Linux (authconfig, bash, curl, evince, firefox, freeradius, gdm gnome-session, ghostscript, git, glibc, gnutls, groovy, GStreamer, gtk-vnc, httpd, java-1.7.0-openjdk, kernel, libreoffice, libsoup, libtasn1, log4j, mariadb, mercurial, NetworkManager, openldap, openssh, pidgin, pki-core, postgresql, python, qemu-kvm, samba, spice, subversion, tcpdump, tigervnc fltk, tomcat, X.org, and xmlsec1), SUSE (git), and Ubuntu (augeas, cvs, and texlive-base).

Oracle has announcedthat it is considering stepping back from management of the Java EnterpriseEdition. "We are discussing how we can improve the Java EEdevelopment process following the delivery of Java EE 8. We believe thatmoving Java EE technologies including reference implementations and testcompatibility kit to an open source foundation may be the right next step,in order to adopt more agile processes, implement more flexible licensing,and change the governance process. We plan on exploring this possibilitywith the community, our licensees and several candidate foundations to seeif we can move Java EE forward in this direction."

The first stop in the search for a free accounting system that can replaceQuickBooks is a familiar waypoint: the GnuCash application. GnuCash has beenaround for many years and is known primarily as a personal-finance tool,but it has acquired some business features as well. The question is: arethose business features solid enough to allow the program to serve as areplacement for QuickBooks?

The registration for the NetDev 2.2 networking conference is now open. It will be held in Seoul, Korea November 8-10. As usual, it will be preceded by the invitation-only Netconf for core kernel networking hackers. "Netdev 2.2 is a community-driven conference geared towards Linux netheads. Linux kernel networking and user space utilization of the interfaces to the Linux kernel networking subsystem are the focus. If you are using Linux as a boot system for proprietary networking, then this conference _may not be for you_." LWN covered these conferences in 2016 and earlier this year; with luck, we will cover these upcoming conferences as well.

Security updates have been issued by Arch Linux (newsbeuter), Debian (augeas, curl, ioquake3, libxml2, newsbeuter, and strongswan), Fedora (bodhi, chicken, chromium, cryptlib, cups-filters, cyrus-imapd, glibc, mingw-openjpeg2, mingw-postgresql, qpdf, and torbrowser-launcher), Gentoo (bzip2, evilvte, ghostscript-gpl, Ked Password Manager, and rar), Mageia (curl, cvs, fossil, jetty, kernel, kernel-linus, kernel-tmb, libmspack, mariadb, mercurial, potrace, ruby, and taglib), Oracle (kernel), Red Hat (xmlsec1), and Ubuntu (graphite2 and strongswan).

Gentoo has long provided a hardened kernel package, but that iscoming to an end. "As you may know the core ofsys-kernel/hardened-sources has been the grsecurity patches. Recently thegrsecurity developers have decided to limit access to these patches. As aresult, the Gentoo Hardened team is unable to ensure a regular patchingschedule and therefore the security of the users of these kernelsources. Thus, we will be masking hardened-sources on the 27th of Augustand will proceed to remove them from the package repository by the end ofSeptember."

The 4.13-rc6 kernel prepatch is out."So everything still looks on target for a normal release schedule,which would imply rc7 next weekend, and then the final 4.13 the weekafter that.Unless something happens, of course. Tomorrow is the solar eclipse,and maybe it brings doom and gloom even beyond the expected Oregontrafficalypse. You never know."

Power-efficient workqueues were first introduced in the 3.11 kernel release; since then, fifty or sosubsystems and drivers have been updated to use them. These workqueuescan be especially useful on handheld devices (like tablets andsmartphones), where power is at a premium.ARM platforms with power-efficient workqueues enabled on Ubuntu andAndroid have shown significant improvements in energy consumption (up to15% for some use cases).

Security updates have been issued by Debian (kernel and libmspack), Fedora (groovy18 and nasm), openSUSE (curl, java-1_8_0-openjdk, libplist, shutter, and thunderbird), Oracle (git, groovy, kernel, and mercurial), Red Hat (rh-git29-git), SUSE (openvswitch), and Ubuntu (c-ares, clamav, firefox, libmspack, and openjdk-7).

Security updates have been issued by CentOS (git), Debian (firefox-esr and mariadb-10.0), Gentoo (bind and tnef), Mageia (kauth, kdelibs4, poppler, subversion, and vim), openSUSE (fossil, git, libheimdal, libxml2, minicom, nodejs4, nodejs6, openjpeg2, openldap2, potrace, subversion, and taglib), Oracle (git and kernel), Red Hat (git, groovy, httpd24-httpd, and mercurial), Scientific Linux (git), and SUSE (freeradius-server, ImageMagick, and subversion).

The LWN.net Weekly Edition for August 17, 2017 is available.

Stable kernels 4.12.8, 4.9.44, 4.4.83, and 3.18.66 have been released. Each contains important fixes throughout the tree and users should upgrade.

<p>A bug that allows an attacker to overwrite a function pointer in the kernelopens up a relativelyeasy way to compromise the kernel—doubly so, if an attacker simplyneeds to wait for the kernel use the compromised pointer. There are varioustechniques that can be used to protect kernel function pointers that areset at either compile or initialization time, but there are some pointersthat are routinely set as the kernel runs; timer completion functions are agood example. An RFC patch posted to the kernel-hardening mailing listwould add a way to detect that those function pointers have been changedin an unexpected way and to stop the kernel from executing that code.

Earlier this month we reported that theKrita Foundation was having some financial difficulties. The KritaFoundation has an update with thanks toall who donated. "So, even though we’re going to get another accountant’s bill of about 4500 euros, we’ve still got quite a surplus! As of this moment, we have €29,657.44 in our savings account!That means that we don’t need to do a fund raiser in September. Like we said, we’ve still got some features to finish."

The startup time for the Python interpreter has been discussed by the coredevelopers and others numerous times over the years; optimization effortsare made periodically as well.Startup time can dominate the execution time of command-line programswritten in Python,especially if they import a lot of other modules. Python startup time isworse than some other scripting languages and more recent versions of thelanguage are taking more than twice as long to start up when compared toearlier versions (e.g. 3.7 versus 2.7).The most recent iteration of the startup timediscussion has played out in the python-dev and python-ideas mailing listssince mid-July. This time, the focus has been on the collections.namedtuple()data structure that is used in multiple places throughout the standardlibrary and in other Python modules, but the discussion has been morewide-ranging than simply that.

Security updates have been issued by CentOS (firefox, httpd, and java-1.7.0-openjdk), Fedora (cups-filters, potrace, and qpdf), Mageia (libsoup and mingw32-nsis), openSUSE (kernel), Oracle (httpd, kernel, spice, and subversion), Red Hat (httpd, java-1.7.1-ibm, and subversion), Scientific Linux (httpd), Slackware (xorg), SUSE (java-1_8_0-openjdk), and Ubuntu (firefox, linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon, linux-lts-xenial, postgresql-9.3, postgresql-9.5, postgresql-9.6, and ubufox).

The Solus distribution project has announcedthe availability of Solus 3. "This is the third iteration ofSolus since our move to become a rolling release operating system. Unlikethe previous iterations, however, this is a release and not asnapshot. We’ve now moved away from the 'regular snapshot' model toaccommodate the best hybrid approach possible - feature rich releases withexplicit goals and technology enabling, along with the benefits of acurated rolling release operating system." Headline featuresinclude support for the Snap packaging format, a lot of desktop changes,and numerous software updates. (LWN looked atSolus in 2016).

The GNOME project was founded by Miguel de Icaza and Federico Mena Quinteroon August 15, 1997, so today the project celebratesits 20th birthday. "There have been 33 stable releases since the initial release of GNOME 1.0 in 1999. The latest stable release, GNOME 3.24 “Portland,” was well-received. “Portland” included exciting new features like the GNOME Recipes application and Night Light, which helps users avoid eyestrain. The upcoming version of GNOME 3.26 “Manchester,” is scheduled for release in September of this year. With over 6,000 contributors, and 8 million lines of code, the GNOME Project continues to thrive in its twentieth year."

Distributions like Debian have a clear policy on the software they ship; asa general rule, only free software can be considered for inclusion. Howthat policy should be applied to software that interactswith proprietary systems is not entirely clear, though. A recentdiscussion on a package that interfaces with a proprietary network service seems unlikely to lead to anychanges in policy, but it does highlight a fault line within the Debiancommunity.

Security updates have been issued by Arch Linux (audiofile, git, jdk7-openjdk, libytnef, mercurial, spice, strongswan, subversion, and xorg-server), Debian (gajim, krb5, and libraw), Fedora (kernel, postgresql, sscep, subversion, and varnish), Mageia (firefox, phpldapadmin, and x11-server), Red Hat (kernel and spice), SUSE (subversion), and Ubuntu (libgd2).

Lars Wirzenius announcesthat he is ending development of the Obnam backup system. "Aftersome careful thought, I fear that the maintainability problems of Obnam canrealistically only be solved by a complete rewrite from scratch, and I'mnot up to doing that. If you use Obnam, you should migrate to some otherbackup solution. Don't worry, you have until the end of the year. I will bearound and I intend to fix any serious bugs in Obnam; in particular,security flaws. But you should start looking for a replacement soonerrather than later." LWN looked atObnam in 2012.

While the best way to avoid performance problems associated with pagefaults is usually to avoid faulting altogether, that is not always anoption. Thus, it is important that the kernel handle page faults with aminimum of overhead. One particular pain point in current kernels comesabout in multi-threaded workloads that are all incurring faults in thesame address space. Speculative page-fault handling is an old idea forimproving the scalability of such workloads that may finally be approachinga point where it can be considered for inclusion.

Security updates have been issued by Debian (botan1.10, cvs, firefox-esr, iortcw, libgd2, libgxps, supervisor, and zabbix), Fedora (curl, firefox, git, jackson-databind, libgxps, libsoup, openjpeg2, potrace, python-dbusmock, spatialite-tools, and sqlite), Mageia (cacti, ffmpeg, git, heimdal, jackson-databind, kernel-linus, kernel-tmb, krb5, php-phpmailer, ruby-rubyzip, and supervisor), openSUSE (firefox, librsvg, libsoup, ncurses, and tcmu-runner), Oracle (firefox), Red Hat (java-1.8.0-ibm), Slackware (git, libsoup, mercurial, and subversion), and SUSE (kernel).

The 4.13-rc5 kernel prepatch is available,right on schedule. "Go forth and test, and everything says thatwe'll get 4.13 out in our usual timely manner."

The 4.12.7,4.9.43,4.4.82, and3.18.65 stable kernel updates are out; eachcontains a relatively small set of important fixes.

Greg Kroah-Hartman has released stable kernels 4.12.6, 4.9.42, 4.4.81, and 3.18.64. All of them contain important fixesand users should upgrade.

Emmanuele Bassi writes about themismatch between the traditional distribution packaging model and whatthe world seems to actually want. "The more I think about it, the less I understand how that ever worked in the first place. It is not a mystery, though, why it’s a dying model.When I say that 'nobody develops applications like the Linux distributionsencourages and prefers' I’m not kidding around: Windows, macOS, iOS,Electron, and Android application developers are heavily based on theconcept of a core set of OS services; a parallel installable blocks ofsystem dependencies shipped and retired by the OS vendor; and a bundlingsystem that allows application developers to provide their owndependencies, and control them."

Security updates have been issued by Arch Linux (firefox, flashplugin, lib32-flashplugin, libsoup, and varnish), Debian (freeradius, git, libsoup2.4, pjproject, postgresql-9.1, postgresql-9.4, postgresql-9.6, subversion, and xchat), Fedora (gsoap, irssi, knot-resolver, php-horde-horde, php-horde-Horde-Core, php-horde-Horde-Form, php-horde-Horde-Url, php-horde-kronolith, php-horde-nag, and php-horde-turba), Mageia (perl-XML-LibXML), Oracle (libsoup), Red Hat (firefox and libsoup), SUSE (kernel and libsoup), and Ubuntu (git, kernel, libsoup2.4, linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon, linux, linux-raspi2, linux-hwe, linux-lts-trusty, linux-lts-xenial, php5, php7.0, and subversion).

It turns out that even rather different source-code management systems canhave similar vulnerabilities. This can be seen in the Git v2.14.1,Mercurial 4.3, andSubversion 1.9.7 releases (plus updates ofolder releases). In each case, it's possible to provide a maliciousrepository URLthat ends up executing code; these URLs can be buried outof sight in existing repositories. Updating would be a good idea,regardless of which system you use.

The kernel's development community is large, to the point that it is oftenfar from obvious who a given patch should be sent to. As the community hasgrown, it has developed mechanisms for tracking that information centeredon a text file called MAINTAINERS. But now it would appear thatthis scalability mechanism has scalability problems of its own.

Security updates have been issued by Debian (firefox-esr), Fedora (cacti, community-mysql, and pspp), Mageia (varnish), openSUSE (mariadb, nasm, pspp, and rubygem-rubyzip), Oracle (evince, freeradius, golang, java-1.7.0-openjdk, log4j, NetworkManager and libnl3, pki-core, qemu-kvm, and X.org), Red Hat (flash-plugin), and Slackware (curl and mozilla).

The LWN.net Weekly Edition for August 10, 2017 is available.

Device trees have become, in a relatively short time, the preferred way toinform the kernel of the available hardware on systems where that hardwareis not discoverable — most ARM systems, among others. In short, adevice tree is a textual description of a system's hardware that iscompiled to a simple binary format and passed to the kernel by thebootloader. The source format for device trees has been established for along time — longer than Linux has been using it. Perhaps it's time for achange, but a proposal for a newdevice-tree source format has generated a fair amount of controversy in thesmall corner of the community that concerns itself with such things.

Fedora 24 reached its end of life on August 8. There will be no moreupdates, including security updates. Please refer to thispage for information about upgrades.

OSGeo-Live is a live DVD/USB/VM distribution that includes a variety ofopen-source geospatial software. Version 11.0 is "a majorreboot, with a refocus on leading applications and emphasis on quality overquantity. Less mature parts of the projects have been dropped with atargeted focus placed on upgrading and improving documentation."

Security updates have been issued by Mageia (atril, mpg123, perl-SOAP-Lite, and virtualbox), openSUSE (kernel and libzypp, zypper), Oracle (authconfig, bash, curl, gdm and gnome-session, ghostscript, git, glibc, gnutls, gtk-vnc, kernel, libreoffice, libtasn1, mariadb, openldap, openssh, pidgin, postgresql, python, qemu-kvm, samba, tcpdump, tigervnc and fltk, and tomcat), Red Hat (kernel, kernel-rt, openstack-neutron, and qemu-kvm), and SUSE (puppet and tcmu-runner).

It is well understood that old and unmaintained software tends to be abreeding ground for security problems. These problems are never welcome, but theyare particularly worrying when the software in question is a net-facingtool like a web browser. Standalone browsers are (hopefully) reasonablywell maintained, but those are not the only web browsers out there; theycan also be embedded into applications. The effort to do away with oneunmaintained embedded browser is finally approaching its conclusion, butthe change appears to have caught some projects unaware.

Firefox 55.0 has been released. From the releasenotes: "Today's release brings innovative functionality, improvements to core browser performance, and more proof that we’re committed to making Firefox better than ever. New features include support for WebVR, making Firefox the first Windows desktop browser to support VR experiences. Performance changes include significantly faster startup times when restoring lots of tabs and settings that let users take greater control of our new multi-process architecture. We’ve also upgraded the address bar to make finding what you want easier, with search suggestions and the integration of our one-click search feature, and safer, by prioritizing the secure - https - version of sites when possible."

Daniel Vetter describeshow the kernel community scales and why he feels that the GitHub model tends not towork for the largest projects. "Unfortunately github doesn’t supportthis workflow, at least not natively in the github UI. It can of course bedone with just plain git tooling, but then you’re back to patches onmailing lists and pull requests over email, applied manually. In my opinionthat’s the single one reason why the kernel community cannot benefit frommoving to github. There’s also the minor issue of a few top maintainersbeing extremely outspoken against github in general, but that’s a notreally a technical issue. And it’s not just the linux kernel, it’s all hugeprojects on github in general which struggle with scaling, because githubdoesn’t really give them the option to scale to multiple repositories,while sticking to with a monotree."

Security updates have been issued by Fedora (cacti, freerdp, remmina, subversion, supervisor, webkitgtk4, and wireshark), Mageia (gdm, librsvg, php, libgd, and swftools), openSUSE (cacti, cacti-spine), Red Hat (java-1.7.0-openjdk and kernel), SUSE (kernel), and Ubuntu (freerdp, kernel, linux-lts-trusty, and shotwell).

When a small business contemplates getting away from a proprietaryaccounting tool like QuickBooks in favor of free software like GnuCash, thefirst order of business is usually finding a way to liberate thatbusiness's accounting data for input into a new system. Strangely enough,Intuit, the creator of QuickBooks, never quite got around to making thateasy to do. But it turns out that, with a bit of effort, this move can be made. Getting there involveswandering through an undocumented wilderness; this article is at attempt tomake things easier for the next people to come along.

Stable kernels 4.12.5, 4.9.41, and 4.4.80 have been released. All of themcontain important fixes and users should upgrade.

Security updates have been issued by Debian (chromium-browser, kernel, libsndfile, and qemu), Fedora (php-PHPMailer, qpdf, qt5-qtwebengine, qt5-qtwebkit, and ruby), Mageia (evince), openSUSE (icoutils and poppler), Red Hat (log4j), SUSE (kernel), and Ubuntu (openvpn and tiff).

The 4.13-rc4 kernel prepatch is out fortesting."Anyway, nothing really stands out, and while I really hope that we'llsee things calm down further, everything looks pretty much on trackfor a normal release.So go test things out. By now it should really be pretty safe."

Nonvolatile memory offers the promise of fast, byte-addressable storagethat persists over power cycles. Taking advantage of that promiserequires the imposition of some sort of directory structure so that thepersistent data can be found. There are a few approaches to theimplementation of such structures, but the usual answer is to employ afilesystem, since managing access to persistent data is what filesystemswere created to do. But traditional filesystems are not a perfect match tononvolatile memory, so there is a natural interest in new filesystems thatwere designed for this media from the beginning. The recently posted NOVA filesystem is a new entry in this race.

Git v2.14.0 has been released with several notable changes, many updates,and plenty of bug fixes. The release notes (below) contain the details.

Security updates have been issued by Fedora (evince and rt), Mageia (catdoc, freerdp, kernel, qpdf, R-base, spice, sqlite3, and tcpdump), SUSE (kernel and libzypp, zypper), and Ubuntu (linux, linux-aws, linux-gke, linux-raspi2, linux-snapdragon, linux, linux-raspi2, linux-hwe, and linux-lts-xenial).