LWN.net

The LWN.net Weekly Edition for November 29, 2018 is available.

Malware inserted into a popular npmpackage has put some users at risk of losing Bitcoin, which is certainlyworrisome. More concerning, though, is the implications of how the malwaregot into the package—and how the package got distributed. This is not thefirst time we have seen package-distribution channels exploited, nor willit be the last, but the underlying problem requires more than a technicalsolution. It is, fundamentally, a social problem: trust.

Security updates have been issued by Arch Linux (powerdns-recursor and samba), Debian (ghostscript), Fedora (community-mysql, flatpak, gettext, git, php-PHPMailer, php-phpmailer6, and wireshark), Oracle (kernel and NetworkManager), Scientific Linux (ghostscript, kernel, NetworkManager, and sos-collector), SUSE (dpdk, java-1_7_1-ibm, kernel, python-oslo.cache, python-oslo.concurrency, python-oslo.db, python-oslo.log, python-oslo.messaging, python-oslo.middleware, python-oslo.serialization, python-oslo.service, python-oslo.utils, python-oslo.versionedobjects, python-oslo.vmware, python-oslotest, qemu, rubygem-loofah, tiff, tomcat, and util-linux), and Ubuntu (git, openjdk-8, openjdk-lts, samba, systemd, and webkit2gtk).

A recurring topic in filesystem-developer circles is on handlingcase-insensitive file names. Filesystems for other operating systems doso but, by and large, Linux filesystems do not. In the Kernel Summit trackof the 2018 Linux Plumbers Conference (LPC),Gabriel Krisman Bertazi described his plans for making Linux filesystemsencoding-aware as part of an effort to make ext4, and possibly otherfilesystems, interoperable with case-insensitivity in Android, Windows, and macOS.

Greg Kroah-Hartman has released stable kernels 4.19.5, 4.14.84, 4.9.141, 4.4.165, and 3.18.127. They all contain important fixes andusers should upgrade.

Security updates have been issued by Debian (gnuplot and samba), Fedora (flatpak, kernel-headers, kernel-tools, mariadb-connector-c, php-PHPMailer, php-phpmailer6, and xml-security-c), Gentoo (binutils, libav, mupdf, spice-gtk, strongswan, and tablib), Mageia (libpng(12), mariadb, and openssl), Oracle (ghostscript), Red Hat (.NET Core, ghostscript, java-1.7.1-ibm, kernel, kernel-alt, kernel-rt, NetworkManager, rh-nginx112-nginx, rh-nginx114-nginx, and sos-collector), Scientific Linux (389-ds-base, binutils, curl and nss-pem, fuse, git, glibc, glusterfs, GNOME, gnutls, jasper, java-1.7.0-openjdk, java-11-openjdk, kernel, krb5, libcdio, libkdcraw, libmspack, libreoffice, libvirt, openssl, ovmf, python, python-paramiko, samba, setup, sssd, thunderbird, wget, wpa_supplicant, X.org X11, xerces-c, xorg-x11-server, zsh, and zziplib), SUSE (dom4j, glib2, java-1_7_0-ibm, java-1_7_1-ibm, openssh, postgresql94, procps, qemu, and tiff), and Ubuntu (samba).

The kernelci.org project develops andoperates a distributed testing infrastructure for the kernel. It continuously builds,boots, and tests multiple kernel trees on various types of boards. Kevin Hilman and Gustavo Padovan led a session in the Testing& Fuzzing microconference at the 2018 Linux Plumbers Conference (LPC)to describe the project, its goals, and its future.

"Who's on Team Xmas Tree?" asked Dan Williams at the beginning of his talkin the Kernel Summit track of the 2018Linux Plumbers Conference. Hewas referring to a rule for the ordering of local variable declarationswithin functions that is enforced by a minority of kernel subsystemmaintainers — one of many examples of "local customs" that can surprisedevelopers when they submit patches to subsystems where they are notaccustomed to working. Documenting these varying practices is a small partof Williams's project to create a kernel maintainer's manual, but it seemsto be where the effort is likely to start.

Security updates have been issued by Debian (gnuplot5, icecast2, liblivemedia, otrs2, phpbb3, roundcube, squid3, and xml-security-c), Fedora (kio-extras, tmux, and xen), Gentoo (asterisk, chromium, exiv2, ghostscript-gpl, and thunderbird), openSUSE (libwpd, openssl, openssl-1_1, postgresql10, and SDL2_image), Red Hat (chromium-browser, rh-mysql57-mysql, rh-nginx110-nginx, and rh-nginx18-nginx), SUSE (exiv2, libgcrypt, rpm, and tiff), and Ubuntu (firefox and qemu).

Linus has released the 4.20-rc4 kernelprepatch. "Nothing looks particularly odd or scary, although we dohave some known stuff still pending."

Greg Kroah-Hartman has released a number of stable kernels over the lastfew days, 3.18.126 on November 22, and,on November 23: 4.19.4, 4.14.83, and 4.9.139. Two problems were reported for4.9.139, which quickly led to the release of 4.9.140. As usual, these kernels containimportant fixes; users of those series should upgrade.

Security updates have been issued by Arch Linux (flashplugin, lib32-libtiff, and webkit2gtk), Debian (libphp-phpmailer and openjdk-7), Mageia (flash-player-plugin, Ghostscript, and poppler), openSUSE (chromium and virtualbox), and SUSE (java-1_8_0-ibm, libwpd, openssl, openssl-1_1, realtime-kernel, salt, and SDL_image).

Security updates have been issued by Debian (ceph, openssl, and pixman), Fedora (kernel-headers, kernel-tools, libconfuse, python-urllib3, and xen), Mageia (gettext and roundcubemail), openSUSE (GraphicsMagick and libwpd), Oracle (thunderbird), Slackware (openssl), and Ubuntu (libapache2-mod-perl2).

Stable kernels 4.19.3, 4.18.20, 4.14.82, 4.9.138, and 4.4.164 have been released with the usual setof important fixes. This is the last 4.18.y kernel release and users shouldupgrade to 4.19.y.

Security updates have been issued by Arch Linux (libtiff), CentOS (java-1.7.0-openjdk, spice-server, and thunderbird), Debian (jasper, liblivemedia, ruby-i18n, and ruby-rack), Fedora (curl, elfutils, firefox, kde-connect, kio-extras, libarchive, poppler, and webkit2gtk3), openSUSE (chromium, GraphicsMagick, kernel, libmatroska, mkvtoolnix, SDL2_image, and squid), Oracle (qemu), and Red Hat (flash-plugin and kernel).

There has been a great deal of discussion around the kernel project'srecently adopted code of conduct (CoC), but little of that has happened in anopen setting. That changed to an extent when a panel discussion was heldduring the Kernel Summit track at the 2018 Linux Plumbers Conference.Panelists Mishi Choudhary, Olof Johansson, Greg Kroah-Hartman, and ChrisMason took on a number of issues surrounding the CoC in a generallycalm and informative session.

Security updates have been issued by Arch Linux (chromium), Debian (mariadb-10.1, openjpeg2, systemd, and uriparser), Mageia (389-ds-base, apache, and soundtouch), SUSE (libwpd, py26-compat-salt, salt, and SMS3.1), and Ubuntu (systemd).

The closing event at the 2018 Linux Plumbers Conference (LPC) was apanel ofkernel developers. The participants were Laura Abbott, Anna-MariaGleixner, Shuah Khan, Julia Lawall, and Anna Schumaker; moderation wasprovided by Kate Stewart. This fast-moving discussion covered thechallenges of kernel development, hardware vulnerabilities, scaling thekernel, and more.

Security updates have been issued by Arch Linux (grafana and patch), Debian (chromium-browser), Fedora (cabextract, curl, elfutils, firefox, flatpak, glusterfs, kernel, kernel-headers, kernel-tools, kio-extras, libmspack, mariadb, mupdf, poppler, suricata, and wireshark), Mageia (hylafax+, jhead, libmspack/cabextract, nginx, sdl2/mingw-SDL2, and squid), openSUSE (amanda, apache-pdfbox, chromium, ImageMagick, LibreOffice and dependency libraries, libxkbcommon, openssh, systemd, and xorg-x11-server), and SUSE (ImageMagick, openssh, squid, and squid3).

The 4.20-rc3 kernel prepatch is out fortesting. "The changes in rc3 are pretty tiny, which means that thestatistics look slightly different from the usual ones - drivers onlyaccount for less than a third of the patch, for example."

Security updates have been issued by Fedora (lldpad, pdns, and php), Mageia (flash-player-plugin, gdal, mutt, patch, php-pear-CAS, postgresql9.4|6, ruby-rack, and teeworlds), SUSE (kernel-rt, postgresql10, and squid), and Ubuntu (openjdk-7).

Android devices are based on the Linux kernel but, since the beginning,those devices have not run mainline kernels. The amount of out-of-treecode shipped on those devices has been seen as a problem for most of this time, and significant resources have been dedicated to reducing it.At the 2018 Linux PlumbersConference, Sandeep Patil talked about this problem and what is beingdone to address it. The dream of running mainline kernels on Androiddevices has not yet been achieved, but it may be closer than many people think.

Red Hat has announcedthe release of RHEL 8 Beta. "Red Hat Enterprise Linux 8 Beta introduces the concept of Application Streams to deliver userspace packages more simply and with greater flexibility. Userspace components can now update more quickly than core operating system packages and without having to wait for the next major version of the operating system. Multiple versions of the same package, for example, an interpreted language or a database, can also be made available for installation via an application stream. This helps to deliver greater agility and user-customized versions of Red Hat Enterprise Linux without impacting the underlying stability of the platform or specific deployments."

Security updates have been issued by Fedora (kde-connect, mingw-SDL2_image, SDL2_image, and subscription-manager), Red Hat (flash-plugin), SUSE (openssh-openssl1, systemd, and thunderbird), and Ubuntu (kernel, linux, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oem, linux-raspi2, linux, linux-aws, linux-gcp, linux-kvm, linux-raspi2, linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon, linux-azure, linux-hwe, linux-azure, linux-gcp, linux-lts-trusty, linux-lts-xenial, linux-aws, postgresql-10, and python2.7).

The LWN.net Weekly Edition for November 15, 2018 is available.

In the first session of the Testing& Fuzzing microconference at the 2018 Linux Plumbers Conference (LPC), KevinHilman gave a report on the recently held Automated TestingSummit (ATS). Since the summit was an invitation-only gathering of 35people, there were many at LPC who were not at ATS but had a keeninterest in what was discussed. The summit came out of a realization thatthere is a lot of kernel testing going on in various places, but not a lotof collaboration between those efforts, Hilman said.

Device trees have become ubiquitous in recent years as a way ofdescribing the hardware layout of non-discoverable systems, such as manyARM-based devices. The device-tree bindings define how a particularpiece of hardware is described in a device tree. Drivers then implementthose bindings. The device-tree documentation shows how to use the bindings to describe systems: which properties are available and which valuesthey may have. In theory, the bindings, drivers and documentation should beconsistent with each other. In practice, they are often not consistent and,even when they are, using those bindings correctly in actual device treesis not a trivial task. As a result, developers havebeen considering formal validation for device-tree files for years.Recently, Rob Herring proposeda move to a more structured documentation format for device-tree bindingsusing JSON Schema to allow automatedvalidation.

The results of the 2018 election for members of the Linux Foundation'sTechnical Advisory Board have been posted; the members elected this timearound are Chris Mason, Laura Abbott, Olof Johansson, Dan Williams, andKees Cook. Abbott and Cook are new members to the board this time around.(The other TAB members are Ted Ts'o, Greg Kroah-Hartman, Jonathan Corbet,Tim Bird, and Steve Rostedt).

Stable kernels 4.19.2, 4.18.19, 4.14.81, and 4.9.137 have been released. They all contain arelatively large set of important fixes and users should upgrade.

Security updates have been issued by Arch Linux (powerdns and powerdns-recursor), Debian (ceph and spamassassin), Fedora (feh, flatpak, and xen), Red Hat (kernel, kernel-rt, openstack-cinder, python-cryptography, and Red Hat Single Sign-On 7.2.5), and Ubuntu (python2.7, python3.4, python3.5).

Debian supportsmany architectures and, even for those it does not officially support,there are Debian ports that tryto fill in the gap. For most user applications, it is mostly a matter ofgetting GCC up and running for the architecture in question, then buildingall of the different packages that Debian provides. But for packagesthat need to be built with LLVM—applications or libraries that use Rust,for example—that simple recipe becomes more complicated. How much the lackof Rust support for an unofficial architecture should hold back the rest of the distribution was the subject of a somewhatacrimonious discussion recently.

Security updates have been issued by Debian (firmware-nonfree and imagemagick), Fedora (cabextract, icecast, and libmspack), openSUSE (icecast), Red Hat (httpd24), Slackware (libtiff), SUSE (apache-pdfbox, firefox, ImageMagick, and kernel), and Ubuntu (clamav, spamassassin, and systemd).

User-space developers may be accustomed to thinking of system calls as directcalls into the kernel. Indeed, the first edition of The C ProgrammingLanguage described read() and write() as "adirect entry into the operating system". In truth, user-level"system calls" are just functions in the C library like any other. But whathappens when the developers of the C library refuse to provide access to system calls they don't like? The result is anongoing conflict that has recently flared up again; it shows some of thedifficulties that can arise when the system as a whole has no ultimatedesigner and the developers are not talking to each other.

Security updates have been issued by Arch Linux (curl, lib32-curl, lib32-libcurl-compat, lib32-libcurl-gnutls, libcurl-compat, libcurl-gnutls, systemd, and thunderbird), Debian (ansible, ghostscript, qemu, thunderbird, and xen), Fedora (community-mysql, gettext, links, mysql-connector-java, xen, and zchunk), Gentoo (icecast, libde265, okular, pango, and PHProjekt), Mageia (ansible, audiofile, iniparser, libtiff, mercurial, opencc, and python-dulwich), openSUSE (accountsservice, apache2, audiofile, curl, libarchive, ntfs-3g_ntfsprogs, opensc, python, python-base, qemu, soundtouch, and systemd), Oracle (git, java-1.7.0-openjdk, java-11-openjdk, kernel, python-paramiko, thunderbird, and xorg-x11-server), Red Hat (rh-git29-git), Scientific Linux (thunderbird), SUSE (kernel), and Ubuntu (gettext and libmspack).

The 4.20-rc2 kernel prepatch is out fortesting. "Fairly normal week, aside from me traveling".

The4.18.18,4.14.80,4.9.136,4.4.163, and3.18.125stable kernel updates have all been released; each contains a relativelylarge set of important fixes.The 3.18.x updates may be about to come to an end, since it is not clearthat anybody is using them. "And from what I cansee in the 'real world', no one is actually updating devices that relyon 3.18.y to the newer kernel releases. So I think I'm going to stopmaintaining this tree soon unless someone speaks up and says 'I am usingit!''

Since the beginning, one part of the kernel-development task has beenwatching the mainline to see whether one's work had been merged. That isabout to change with the advent of the pull-request trackerbot, which will inform maintainers when one of their pull requests hasmade it into the mainline. Konstantin Ryabitsev, who put this servicetogether, plans to expand it to other trees once things have settled down.

As a general rule, the kernel is supposed to use the least amount of CPUtime possible; any time taken by the kernel is not available for theapplications the user actually wants to run. As a result, not a lot ofthought has gone into optimizing the execution of kernel-side work requiring largeamounts of CPU. But the kernel does occasionally have to take onCPU-intensive tasks, such as the initialization of the large amounts ofmemory found on current systems. The ktasksubsystem posted by Daniel Jordan is an attempt to improve how thekernel handles such jobs.

Security updates have been issued by Debian (nginx), Fedora (icu, java-1.8.0-openjdk-aarch32, libgit2, php-pear-CAS, roundcubemail, and ruby), Gentoo (firefox, libX11, openssl, and python), openSUSE (thunderbird), Oracle (java-11-openjdk, kernel, and spice-server), Red Hat (java-1.8.0-ibm and thunderbird), Scientific Linux (spice-server), SUSE (curl, libepubgen, liblangtag, libmwaw, libnumbertext, libreoffice, libstaroffice, libwps, myspell-dictionaries, xmlsec1, libxkbcommon, openssh, and xorg-x11-server), and Ubuntu (pyopenssl).

It has been nearly 13 years since Jeff Garzik proclaimed that Linux was "proving itssuperiority in the area of crappy wireless (WiFi) support".Happily, the situation has improved somewhat since then, but that doesn'tmean that things can't get better yet. During the Embedded LinuxConference portion of the 2018Open Source Summit Europe, Marcel Holtmann described the work beingdone to create iwd, a new systemfor configuring and managing WiFi connections. If this project has its way, future users will have little roomfor complaint about how WiFi works on Linux systems.

There is a whole new set of PostgreSQL releases out there, the main purposeof which is to include an important security fix."Using a purpose-crafted trigger definition, an attacker can runarbitrary SQL statements with superuser privileges when a superuser runs`pg_upgrade` on the database or during a pg_dump dump/restore cycle.This attack requires a `CREATE` privilege on some non-temporary schemaor a `TRIGGER` privilege on a table. This is exploitable in the defaultPostgreSQL configuration, where all users have `CREATE` privilege on`public` schema." Note that this is the final update for the 9.3series; users on that version should be planning an upgrade in the nearfuture.

Security updates have been issued by CentOS (python-paramiko and thunderbird), Debian (firefox-esr, libdatetime-timezone-perl, and mariadb-10.0), Fedora (curl, NetworkManager, and xorg-x11-server), openSUSE (kernel), Oracle (java-1.7.0-openjdk, python-paramiko, thunderbird, and xorg-x11-server), Red Hat (java-11-openjdk and spice-server), SUSE (firefox, kernel, and SDL_image), and Ubuntu (nginx).

The LWN.net Weekly Edition for November 8, 2018 is available.

A "joke" in the glibc manual—targeting a topic that is, at best,sensitive—has come up for discussion on the glibc-alpha mailing listagain. When we looked at the controversyin May, Richard Stallman had put his foot down and a patch removing thejoke—though opinions of its amusement value vary—was reverted. Shortlyafter that article was published, a "cool down period" wasrequested(and honored), but that time has expired. Other developments inthe GNU project have given some reason to believe that the time is ripe tofinally purge the joke, but that may not work out any better than the lastattempt.

<p>There is always at least a small risk when installing a package for adistribution. By its very nature, package installation is an invasiveprocess; some packages require the ability to make radical changes to thesystem—changes that users surely would not want other packages to takeadvantage of. Packages that are made available by distributions are vettedfor problems of this sort, though, of course, mistakes can be made.Third-party packages are an even bigger potential problem because they lackthis vetting, as was discussed in early October on the debian-devel mailinglist. Solutions in this area are not particularly easy, however.

Security updates have been issued by Arch Linux (ghostscript), Debian (curl), Fedora (curl, thunderbird, and zchunk), openSUSE (thunderbird), Oracle (389-ds-base, binutils, curl and nss-pem, glusterfs, gnutls, jasper, kernel, krb5, libcdio, libkdcraw, libmspack, libvirt, openssl, ovmf, python, samba, setup, sssd, wget, wpa_supplicant, xerces-c, zsh, and zziplib), Red Hat (xerces-c), SUSE (libarchive and systemd), and Ubuntu (ppp and spamassassin).

We looked atthe WireGuard virtual privatenetwork (VPN)back in August and noted that it is built on top of a newcryptographic API being developed for the kernel, which is calledZinc. There has been some controversy about Zinc and why a brand new API was needed when the kernel already has an extensive crypto API. A recenttalk by lead WireGuard developer Jason Donenfeld at Kernel Recipes 2018 would appear to be a serious attempt to reach out, engagewith that question, and explain the what, how, and why of Zinc.

Security updates have been issued by Debian (glusterfs, gthumb, and mysql-5.5), Red Hat (389-ds-base, kernel, and xerces-c), Slackware (mariadb), SUSE (accountsservice, curl, icinga, kernel, and opensc), and Ubuntu (libxkbcommon, openssh, and ruby1.9.1, ruby2.0, ruby2.3, ruby2.5).

At the end of the 4.20 merge window, 12,125 non-mergechangesets had been pulled into the mainline kernel repository; 6,390 camein since last week's summary was written.As is often the case, the latter part of the merge window contained alarger portion of cleanups and fixes, but there were a number of newfeatures in the mix as well.

Stable kernels 4.19.1, 4.18.17, and 4.14.79 have been released. As usual, there areimportant fixes and users should upgrade.