LWN.net

On its face, the netgpupatch set appears to add a useful feature: the ability to copy networkdata directly between a network adapter and a GPU without moving it throughthe host CPU. This patch set has quickly become an example of how not to getwork into the kernel, though; it has no chance of being merged in anythinglike its current form and has created a backlash designed to keep moduleslike it from ever working in mainline kernels. It all comes down to onefundamental mistake: basing kernel work on a proprietary kernel module.

Greg Kroah-Hartman has released the 5.7.12,5.4.55, 4.19.136, 4.14.191, 4.9.232, and 4.4.232 stable kernels. As usual, thesecontain lots of important fixes throughout the tree; users should upgrade.

The X.Org project has announced two security advisories that impact Xserver and libX11. The first advisory for X server is regarding uninitialized memory in AllocatePixmap() that could lead to address space layout randomization bypass. The second, impacting libX11, is a heap corruption caused by integer overflows and signed/unsigned comparisons.

Security updates have been issued by Debian (grub2 and mercurial), Fedora (chromium, firefox, and freerdp), Oracle (firefox and kernel), Red Hat (firefox), Scientific Linux (firefox, grub2, and kernel), and SUSE (ghostscript and targetcli-fb).

Systemd 246 has been released. There is an incredibly long list of newfeatures, many of which have to do with support for encrypted and signeddisk volumes. "Various command line parameters and configuration file settings that configure key or certificate files now optionally take paths to AF_UNIX sockets in the file system. If configured that way a stream connection is made to the socket and the required data read from it. This is a simple and natural extension to the existing regular file logic, and permits other software to provide keys or certificates via simple IPC services, for example when unencrypted storage on disk is not desired."

The Go team has recently publishedseveral draft designs that propose changes to the language, standardlibrary, and tooling: we covered the one on genericsback in June. Last week, the Go team published two draft designs related tofiles: one for a new read-only filesysteminterface, which specifies a minimal interfacefor filesystems, and a second design that proposes a standard way to embedfiles into Go binaries (by building on the filesystem interface).Embedding files into Go binaries is intended to simplify deploymentsby including all of a program's resources in a single binary; thefilesystem interface design was drafted primarily as a building block forthat. There has beena lot of discussion on the draft designs, which has been generallypositive, but there are somesignificant concerns.

Security updates have been issued by Arch Linux (webkit2gtk), CentOS (GNOME, grub2, and kernel), Debian (firefox-esr, grub2, json-c, kdepim-runtime, libapache2-mod-auth-openidc, net-snmp, and xrdp), Gentoo (chromium and firefox), Mageia (podofo), openSUSE (knot and tomcat), Oracle (grub2, kernel, postgresql-jdbc, and python-pillow), Red Hat (firefox, grub2, kernel, and kernel-rt), SUSE (grub2), and Ubuntu (firefox, grub2, grub2-signed, and librsvg).

As reported in the comments on the Grub2 secure-boot vulnerabilities report, the updates for grub2 for RHEL 8 and CentOS 8 are making some systems unbootable. The boot problems are seemingly unrelated to whether the system has secure boot enabled. It may be worth waiting a bit for that to shake out.

The LWN.net Weekly Edition for July 30, 2020 is available.

Last year Sienci Labs finished its Kickstarter campaign for the open-source LongMill Benchtop CNC Router — its second successful open-source CNC machine Kickstarter campaign. CNC routers allow users to mill things (like parts) from raw materials (like a block of aluminum) based on a 3D-model. The LongMill is a significant improvement over the original sold-out Mill One and makes professional-quality machining based entirely on open-source technology a reality. As an owner of a LongMill, I will walk through the various open-source technologies that make this tool a cornerstone of my home workshop.

Several vulnerabilities have been disclosed in the GRUB2 bootloader; theyenable the circumvention of the UEFI secure boot mechanism and thepersistent installation of hostile software. Fixing the problem is not justa matter of getting a new GRUB2 installation, unfortunately."It is important to note that updating the exploitablebinaries does not in fact mitigate the CVE, since an attacker couldbring an old, exploitable, signed copy of a grub binary onto a systemwith whatever kernel they wished to load. In order to mitigate, theUEFI Revocation List (dbx) must be updated on a system. Once the UEFIRevocation List is updated on a system, it will no longer bootbinaries that pre-date these fixes. This includes old install media."

Stable kernels 5.7.11, 5.4.54, 4.19.135, and 4.14.190 have been released. They all containimportant fixes and users should upgrade.

Dart is a BSD-licensed programming language from Google with a mature open-source community supporting the project. It works with multiple architectures, is capable of producing native machine-code binaries, and can also produce JavaScript versions of its applications. Dart version 1.0 was released in 2013, with the most recent version, 2.8, released on June 3 (2.9 is currently in public beta). Among the open-source projects using Dart is the cross-device user-interface (UI) toolkit Flutter. We recently covered the Canonical investment in Flutter to help drive more applications to the Linux desktop, and Dart is central to that story.

Security updates have been issued by Debian (curl, firefox-esr, luajit, and salt), Fedora (clamav, java-1.8.0-openjdk, and java-11-openjdk), Gentoo (claws-mail, dropbear, ffmpeg, libetpan, mujs, mutt, and rsync), openSUSE (qemu), Red Hat (openstack-tripleo-heat-templates), SUSE (freerdp, ldb, rubygem-puma, samba, and webkit2gtk3), and Ubuntu (mysql-5.7, mysql-8.0 and sympa).

Version 5.0 of the GNU nano text editor is out; it contains a number ofimprovements to the editing experience. "With --indicator (or -q or 'set indicator') nano will show a kind of scrollbar on the righthand side of the screen to indicate where in the buffer the viewport is located and how much it covers."

Time, as some have said, is nature's way of keeping everything fromhappening at once. In today's highly concurrent computers, though, timeturns out not to be enough to keep events in order; that task falls to anextensive set of locking primitives and, below those, the formalized viewof memory known as the Linux kernel memory model. It takes a special kindof mind to really understand the memory model, though; kernel developerslacking that particular superpower are likely to make mistakes when workingin areas where the memory model comes into play. Working at that level isincreasingly necessary for performance purposes, though; a recentconversation points out ways in which the kernel could make that kind ofwork easier for ordinary kernel developers.

Firefox 79.0 has been released. This version has improved accessibility forpeople using screen readers. See the releasenotes for more details.

Arduino devices are a favorite among do-it-yourself (DIY) enthusiasts to create, among other things, Internet of Things (IoT) devices. We have previously covered the Espressif ESP8266 family of devices that can be programmed using the Arduino SDK, but the Arduino project itself also provides WiFi-enabled devices such as the Arduino MKR WiFi 1010 board. Recently, the Arduino Security Team raised the problem of security shortcomings of IoT devices in a post, and how the Arduino project is working to make improvements. We will take the opportunity to share some interesting things from that, and also look at the overall state of TLS support in the Arduino and Espressif SDK projects.

As Alex McDonald notes in thissupport request, Google has recently banned the old Usenet groupscomp.lang.forth and comp.lang.lisp from the Google Groups system."Of specific concern is the archive. These are some of the oldestgroups on Usenet, and the depth & breadth of the historical material thathas just disappeared from the internet, on two seminal programminglanguages, is huge and highly damaging. These are the history andcollective memories of two communities that are being expunged, and it'snot great, since there is no other comprehensive archive after Google'spurchase of Dejanews around 20 years ago."Perhaps Google can be convinced to restore the content, but it also seemsthat some of this material could benefit from a more stable archive.

Security updates have been issued by openSUSE (cacti, cacti-spine, go1.13, SUSE Manager Client Tools, and tomcat), Red Hat (postgresql-jdbc and python-pillow), Slackware (mozilla), SUSE (python-Django and python-Pillow), and Ubuntu (clamav, librsvg, libslirp, linux-gke-5.0, linux-oem-osp1, linux-hwe, linux-azure-5.3, linux-gcp-5.3, linux-gke-5.3, linux-hwe, linux-oracle-5.3, and sqlite3).

Version 2.28.0 of the git version control system has been released. "It is smaller than the releases in our recent past, mostly due tothe development cycle was near the shorter end of the spectrum (ourcycles last 8-12 weeks and this was a rare 8-week cycle)."See thisGitHub Blog post for details on the new features in this release.

Security updates have been issued by Debian (e2fsprogs, ffmpeg, milkytracker, mupdf, openjdk-11, and qemu), Fedora (bashtop), Gentoo (ant, arpwatch, awstats, cacti, chromium, curl, dbus, djvu, filezilla, firefox, freexl, fuseiso, fwupd, glib-networking, haml, hylafaxplus, icinga, jhead, lha, libexif, libreswan, netqmail, nss, ntfs3g, ntp, ocaml, okular, ossec-hids, qtgui, qtnetwork, re2c, reportlab, samba, sarg, sqlite, thunderbird, transmission, tre, twisted, webkit-gtk, wireshark, and xen), openSUSE (cacti, cacti-spine, chromium, freerdp, go1.13, kernel, knot, libraw, LibVNCServer, perl-YAML-LibYAML, salt, tomcat, vino, and webkit2gtk3), and SUSE (mailman, rubygem-excon, rust, rust-cbindgen, samba, and tomcat).

The 5.8-rc7 kernel prepatch is out fortesting; Linus is unsure about whether things are slowing down enough ornot. "But it *might* mean that an rc8 is called for. It's not like rc7 is*big* big. We've had bigger rc7's. Both 5.3 and 5.5 had bigger rc7's,but only 5.3 ended up with an rc8.Put another way: it could still go either way. We'll see how thisupcoming week goes."

Mycroft is a free and open-source software project aimed at providing voice-assistant technology, licensed under the Apache 2.0 license. It is an interesting alternative to closed-source commercial offerings such as Amazon Alexa, Google Home, or Apple Siri. Use of voice assistants has become common among consumers, but the privacy concerns surrounding them are far-reaching. There have been multiple instances of law enforcement's interest in the data these devices produce for use against their owners. Mycroft claims to offer a privacy-respecting, open-source alternative, giving users a choice on how much of their personal data is shared and with whom.

Version 3.7 of the Bison parser generator is out. The biggest new featurewould appear to be the generation of "counterexamples" for conflicts —examples of strings that could be parsed in multiple ways. There is alsobetter support for reproducible builds, documentation links in warnings,and more.

Version7.0.0 of the digiKam photo editing and management application is out.This release adds support for a number of new raw formats, support forApple's HEIF format, and a new mosaic plugin. The headline feature,though, appears to be completely reworked face detection: "The newcode, based on recent Deep Neural Network features from the OpenCV library,uses neuronal networks with pre-learned data models dedicated for the FaceManagement. No learning stage is required to perform face detection andrecognition. We have saved coding time, run-time speed, and a improved thesuccess rate which reaches 97% of true positives. Another advantage is thatit is able to detect non-human faces, such as those of dogs."

Security updates have been issued by Debian (qemu), Fedora (java-11-openjdk, mod_authnz_pam, podofo, and python27), openSUSE (cni-plugins, tomcat, and xmlgraphics-batik), Oracle (dbus and thunderbird), SUSE (freerdp, kernel, libraw, perl-YAML-LibYAML, and samba), and Ubuntu (libvncserver and openjdk-lts).

Christian Brauner has posted anovella-length description of the seccomp notifier mechanism and theproblems it is meant to solve."So from the section above it should be clear that seccomp provides afew desirable properties that make it a natural candidate to look at to helpsolve our mknod(2) and mount(2) problem. Since seccomp intercepts syscallsearly in the syscall path it already gives us a hook into the syscall pathof a given task. What is missing though is a way to bring another tasksuch as the LXD container manager into the picture. Somehow we need tomodify seccomp in a way that makes it possible for a container manager tonot just be informed when a task inside the container performs a syscall itwants to be informed about but also how can to make it possible to blockthe task until the container manager instructs the kernel to allow it toproceed."

The PHP project has released PHP 8 Alpha 3, the final alpha release according to the 8.0 release schedule. Feature freeze for the 8.0 release is scheduled for August 4, making this release the last one before features for the latest version of PHP are finalized. PHP 8.0 is scheduled to be released for general availability on November 26.

There are many people in the world who cannot make full use of theircomputers without some sort of accessibility support. Developers, though,have a tendency not to think about accessibility issues themselves; theydon't (usually) need those features and cannot normally even see them. Ina talk at the 2020GUADEC virtual conference, Emmanuele Bassi discussed the need foraccessibility features, their history in GNOME, and his effort to rethinkabout how GNOME supports assistive technology.

Security updates have been issued by Debian (poppler and tomcat8), Fedora (cacti, cacti-spine, java-1.8.0-openjdk, mbedtls, mingw-python3, singularity, and xen), openSUSE (firefox, redis, and singularity), Red Hat (samba), SUSE (java-11-openjdk, qemu, and vino), and Ubuntu (ffmpeg and pillow).

The LWN.net Weekly Edition for July 23, 2020 is available.

SAND Lab at the Universityof Chicago has announcedFawkes, which is a BSD-licensed privacy-protection toolavailable on GitHub."At a high level, Fawkes takes your personal images, and makes tiny,pixel-level changes to them that are invisible to the human eye, in aprocess we call image cloaking. You can then use these "cloaked" photos asyou normally would, sharing them on social media, sending them to friends,printing them or displaying them on digital devices, the same way you wouldany other photo. The difference, however, is that if and when someone triesto use these photos to build a facial recognition model, "cloaked" imageswill teach the model an highly distorted version of what makes you looklike you. The cloak effect is not easily detectable, and will not causeerrors in model training. However, when someone tries to identify you usingan unaltered image of you (e.g. a photo taken in public), and tries toidentify you, they will fail."

The stable kernel trees are quite active, often seeing several releases ina week's time. But they are also meant to be ... well ... stable, so a lotof effort goes into trying to ensure that they do not introduce new bugs orregress the kernel's functionality. One of the stable maintainers, SashaLevin, gave a talk at the virtualOpenSource Summit North America that described the process of ensuring thatthese trees are carefully managed so that they can provide a stable base for their users.

Gnuplot 5.4 has been released, three years after the last major release of the free-softwaregraphing program.In this article we will take a look at five major new capabilities in gnuplot.First, we briefly visit voxel plotting, for visualizing 3D data. Since this isa big subject and the most significant addition to the program, we'll save the detailsfor a subsequent article. Next, we learn about plotting polygons in 3D, another completelynew gnuplot feature. After that, we'll get caught up briefly in spider plots, using themto display some recent COVID-19 infection data. Then we'll see an example of how touse pixmaps, a new feature allowing for the embedding of pictures alongside curves orsurfaces. Finally, we'll look at some more COVID-19 data using the new 3D bar chart.

"Do Not Track" (DNT) is a simple HTTP header that a browser can send tosignal to a web site that the user does not want to be tracked. The DNTheader had a promising start and the support of major browsers almost a decadeago. Most web browsers still support sending it, but in 2020 it is almostuseless because the vast majority of web sites ignore it. Advertisingcompanies, in particular, argued that its legal status was unclear, andthat it was difficult to determine how to interpret the header. There havebeen some relatively recent attempts at legislation to enforce honoring theDNT header, but those efforts do not appear to be going anywhere. Incomparison, the European Union's GeneralData Protection Regulation (GDPR) and the CaliforniaConsumer Privacy Act (CCPA) attempt to solve some of the same problemsas DNT but are legally enforceable.

Stable kernels 5.7.10, 5.4.53, 4.19.134, 4.14.189, 4.9.231, and 4.4.231 have been released. They all containimportant fixes and users should upgrade.

Security updates have been issued by Debian (librsvg and squid), Fedora (mailman, mingw-LibRaw, php-horde-kronolith, and targetcli), openSUSE (openconnect), Red Hat (cloud-init, container-tools:rhel8, dbus, java-1.8.0-openjdk, java-11-openjdk, jbig2dec, kernel, kpatch-patch, mod_auth_openidc:2.3, nodejs:10, openstack-keystone, rh-nodejs10-nodejs, sane-backends, thunderbird, and virt:rhel), SUSE (webkit2gtk3 and xrdp), and Ubuntu (evolution-data-server, linux, linux-aws, linux-aws-hwe, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux, linux-aws, linux-gcp, linux-hwe-5.4, linux-kvm, linux-oracle, linux-raspi-5.4, linux-riscv, linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2, linux-snapdragon, pillow, and python2.7, python3.4, python3.5, python3.6, python3.8).

The memory protection keys feature wasadded to the 4.6 kernel in 2016; it allows user space to group pages into"protection domains" that can have their access restricted independently ofthe normal page protections. There is no equivalent feature for kernelspace; access to memory in the kernel's portion of the address space iscontrolled exclusively by the page protections. That situation maybe aboutto change, though, as a result of the protectionkeys supervisor (PKS) patch set posted by Ira Weiny (with many patcheswritten by Fenghua Yu).

TechRepublic reports that the Linux Foundation has announced the Linux Foundation Public Health initiative (LFPH). Using projects based on the Google Apple Exposure Notification system, the initiative's goal according to LFPH general manager Dan Kohn is "building a global community of leading technology and consulting companies, public health authorities, epidemiologists, and other public health specialists, privacy and security experts, and individual developers." With this announcement is the launch of two open-source projects: COVID Shield and COVID Green.

The Mozilla Hacks blog coverssome recent Firefox changes that will allow code from web sites to useshared memory and high-resolution timers in a (hopefully) safe manner."Together with others in the WHATWG community, we designed a set of headers that meet these requirements.The Cross-Origin-Opener-Policy header allows you to process-isolateyourself from attackers. It also has the desirable effect that attackerscannot have access to your global object if they were to open you in apopup. This prevents XS-Leaks and various navigation attacks. Adopt thisheader even if you have no intention of using shared memory!"

Security updates have been issued by Debian (ksh), openSUSE (ant, chromium, ldb, samba, and LibVNCServer), Red Hat (dbus, kernel, kernel-rt, and NetworkManager), and SUSE (cni-plugins, firefox, openexr, Salt, salt, SUSE Manager Client Tools, and tomcat).

Contact tracing is a way to help prevent the spread of a disease, such asCOVID-19, by identifying an infected person's contacts so that theycan be informed of the infection risk.In the first part of thisseries, we introduced open-source contact-tracing applications developed inresponse to the current pandemic, and described how they work. In thispart, we look into the details of some of them, of both centralized anddecentralized design. These application projects have all released theirsource code, but they differ in the implementation details, licenses used,and whether they accept user requests or patches. We conclude withthe controversies around the tracing applications and the responses to them.

Security updates have been issued by Debian (libopenmpt, nginx, nss, qemu, rails, redis, ruby-sanitize, and tomcat9), Fedora (glibc, libldb, nspr, nss, samba, and webkit2gtk3), openSUSE (cairo, firefox, google-compute-engine, LibVNCServer, mumble, ntp, openconnect, openexr, openldap2, pdns-recursor, python-ipaddress, rubygem-puma, samba, singularity, slirp4netns, thunderbird, xen, and xrdp), and Oracle (.NET Core, .NET Core 3.1, java-1.8.0-openjdk, java-11-openjdk, kernel, and thunderbird).

The 5.8-rc6 kernel prepatch is out fortesting. "Things continue to look very normal, even if this is a big release.rc6 is pretty much par for the course, and nothing in here stands outsize-wise or otherwise."

Back in June, LWN covered a patch setadding a mechanism intended to help systems like Wine emulate Windows system calls on a Linuxsystem. That patch set got a lot of attention and comments, with theresult that its form has changed considerably. Gabriel Krisman Bertazi hasnow posted anew patch set that takes a different approach to solving the same problem.

Security updates have been issued by Fedora (bashtop and python39), openSUSE (openexr), Red Hat (java-1.8.0-openjdk), and Scientific Linux (thunderbird).

Flutter is Google's open-source toolkit to build cross-device (and cross-platform) applications. Based on the Dart programming language released by the company in 2013, Flutter promises developers the ability to write and maintain a single application that runs on all of a user's devices. Flutter applications support deployment on Android, iOS, Web browsers via JavaScript, macOS, and now Canonical and Google have teamed up to support Flutter applications in Linux. Promises of native speed, rapid development, and a growing community make it an interesting technology to take a look at.

Greg Kroah-Hartman has released the 5.7.9,5.4.52, and 4.19.133 stable kernels. As usual, thesecontain lots of important fixes throughout the tree; users should upgrade.

Security updates have been issued by Debian (evolution-data-server and webkit2gtk), Fedora (kernel, snapd, and xen), openSUSE (thunderbird and xen), Oracle (dbus and thunderbird), Red Hat (java-1.8.0-openjdk, java-11-openjdk, jbig2dec, sane-backends, and thunderbird), Scientific Linux (kernel), SUSE (cairo, containerd, docker, docker-runc, golang-github-docker-libnetwork, google-compute-engine, mailman, mercurial, openconnect, openexr, and xrdp), and Ubuntu (libvpx and snapd).