Language Selection

English French German Italian Portuguese Spanish

LWN

Syndicate content
LWN.net is a comprehensive source of news and opinions from and about the Linux community. This is the main LWN.net feed, listing all articles which are posted to the site front page.
Updated: 57 min 38 sec ago

PostgreSQL 11.2, 10.7, 9.6.12, 9.5.16, and 9.4.21 released

Thursday 14th of February 2019 01:39:38 PM
The PostgreSQL project has put out updated releases for all supported versions. "This release changes the behavior in how PostgreSQL interfaces with 'fsync()' and includes fixes for partitioning and over 70 other bugs that were reported over the past three months." The fsync() issue was covered here in April 2018.

[$] LWN.net Weekly Edition for February 14, 2019

Thursday 14th of February 2019 01:11:50 AM
The LWN.net Weekly Edition for February 14, 2019 is available.

[$] io_uring, SCM_RIGHTS, and reference-count cycles

Wednesday 13th of February 2019 04:23:23 PM
The io_uring mechanism that was described here in January has been through a number of revisions since then; those changes have generally been fixing implementation issues rather than changing the user-space API. In particular, this patch set seems to have received more than the usual amount of security-related review, which can only be a good thing. Security concerns became a bit of an obstacle for io_uring, though, when virtual filesystem (VFS) maintainer Al Viro threatened to veto the merging of the whole thing. It turns out that there were some reference-counting issues that required his unique experience to straighten out.

Security updates for Wednesday

Wednesday 13th of February 2019 03:50:07 PM
Security updates have been issued by Arch Linux (aubio, curl, lib32-curl, lib32-libcurl-compat, lib32-libcurl-gnutls, libcurl-gnutls, libu2f-host, python-django, python2-django, rdesktop, and runc), Debian (flatpak), Fedora (flatpak, pdns-recursor, rdesktop, tomcat, and xerces-c27), Mageia (cinnamon, docker, dovecot, golang, java-1.8.0-openjdk, jruby, libarchive, libgd, libtiff, libvncserver, opencontainers-runc, openssh, python-marshmallow, thunderbird, and transfig), openSUSE (python-slixmpp), Oracle (kernel), Red Hat (redhat-virtualization-host), Slackware (lxc), SUSE (curl, firefox, LibVNCServer, nginx, php7, python-numpy, runc, SMS3.2, and thunderbird), and Ubuntu (gvfs, python-django, snapd, and webkit2gtk).

Stable kernel updates

Tuesday 12th of February 2019 08:48:11 PM
Stable kernels 4.20.8, 4.19.21, 4.14.99, and 4.9.156 have been released. They all contain a relatively large number of fixes and users should upgrade.

Plasma 5.15 released

Tuesday 12th of February 2019 06:25:16 PM
KDE has announced the release of Plasma 5.15. "Plasma 5.15 brings a number of changes to the configuration interfaces, including more options for complex network configurations. Many icons have been added or redesigned to make them clearer. Integration with third-party technologies like GTK and Firefox has been improved substantially." This release also features improvements to the Discover software manager. Many other tweaks and improvements are covered in the changelog.

[$] Avoiding the coming IoT dystopia

Tuesday 12th of February 2019 04:48:56 PM

Bradley Kuhn works for the Software Freedom Conservancy (SFC) and part of what that organization does is to think about the problems that software freedom may encounter in the future. SFC worries about what will happen with the four freedoms as things change in the world. One of those changes is already upon us: the Internet of Things (IoT) has become quite popular, but it has many dangers, he said. Copyleft can help; his talk is meant to show how.

CVE-2019-5736: runc container breakout

Tuesday 12th of February 2019 03:48:18 PM
Anybody running containerized workloads with runc (used by Docker, cri-o, containerd, and Kubernetes, among others) will want to make note of a newly disclosed vulnerability known as CVE-2019-5736. "The vulnerability allows a malicious container to (with minimal user interaction) overwrite the host runc binary and thus gain root-level code execution on the host." LXC is also evidently vulnerable to a variant of the exploit.

Security updates for Tuesday

Tuesday 12th of February 2019 03:41:49 PM
Security updates have been issued by Arch Linux (chromium, dovecot, firefox, and spice), Debian (curl, php5, rssh, and wordpress), Fedora (curl, ghostscript, mingw-libconfuse, and radvd), openSUSE (java-11-openjdk and python-urllib3), Red Hat (chromium-browser and kernel), and SUSE (etcd and kernel).

FSF Annual Report now available

Monday 11th of February 2019 09:02:48 PM
The Free Software Foundation has announced that its annual report for fiscal year 2017 is available. "The Annual Report reviews the FSF's activities, accomplishments, and financial picture from October 1, 2016 to September 30, 2017. It is the result of a full external financial audit, along with a focused study of program results. It examines the impact of the FSF's events, programs, and activities, including the annual LibrePlanet conference, the Respects Your Freedom (RYF) hardware certification program, and the fight against Digital Restrictions Management (DRM)."

[$] France enters the Matrix

Monday 11th of February 2019 06:09:45 PM

Matrix is an open platform for secure, decentralized, realtime communication. Matthew Hodgson, the Matrix project leader, came to FOSDEM to describe Matrix and report on its progress. Attendees learned that it was within days of having a 1.0 release and found out how it got there. He also shed some light on what happened when the French reached out to them to see if Matrix could meet the internal messaging requirements of an entire national government.

Security updates for Monday

Monday 11th of February 2019 03:31:52 PM
Security updates have been issued by CentOS (ghostscript, spice, spice-server, and thunderbird), Debian (coturn, freerdp, ghostscript, libreoffice, libu2f-host, mosquitto, and openssh), Fedora (buildbot, java-1.8.0-openjdk, java-11-openjdk, phpMyAdmin, slurm, and spice), openSUSE (python3 and rsyslog), Red Hat (docker and runc), SUSE (avahi, fuse, and LibVNCServer), and Ubuntu (poppler).

PyPy 7.0.0 released

Monday 11th of February 2019 02:25:00 PM
Version 7.0.0 of the PyPy Python interpreter is out. This release supports no less than three upstream Python versions: 2.7, 3.5, and 3.6 (as an alpha release). "All the interpreters are based on much the same codebase, thus the triple release."

Kernel prepatch 5.0-rc6

Monday 11th of February 2019 01:33:18 AM
The 5.0-rc6 kernel prepatch is out. "So while I would have wished for less at this point, nothing in there looks all that odd or scary. I think we're still solidly on track for a normal release."

The CNCF 2018 annual report

Sunday 10th of February 2019 01:36:15 AM
For those wondering what the Cloud Native Computing Foundation is up to, its 2018 annual report [PDF] is now out. "KubeCon + CloudNativeCon has expanded from its start with 500 attendees in 2015 to become one of the largest and most successful open source conferences ever. The KubeCon + CloudNativeCon North America event in Seattle, held December 10-13, 2018, was our biggest yet and was sold out several weeks ahead of time with 8,000 attendees."

LibreOffice 6.2 released

Friday 8th of February 2019 07:53:15 PM
The LibreOffice 6.2 release is out. The headline feature this time around appears to be "NotebookBar": "a radical new approach to the user interface - based on the MUFFIN concept". Other changes include a reworking of the context menus, better change-tracking performance, better interoperability with proprietary file formats, and more.

[$] Blacklisting insecure filesystems in openSUSE

Friday 8th of February 2019 06:27:40 PM
The Linux kernel supports a wide variety of filesystem types, many of which have not seen significant use — or maintenance — in many years. Developers in the openSUSE project have concluded that many of these filesystem types are, at this point, more useful to attackers than to openSUSE users and are proposing to blacklist many of them by default. Such changes can be controversial, but it's probably still fair to say that few people expected the massive discussion that resulted, covering everything from the number of OS/2 users to how openSUSE fits into the distribution marketplace.

Stable kernel 4.4.174 released

Friday 8th of February 2019 05:40:32 PM
Greg Kroah-Hartman has announced the release of the 4.4.174 stable kernel. The patches went out for review on February 7; the kernel contains a backport of a fix for the FragmentSmack denial-of-service vulnerability. "Many thanks to Ben Hutchings for this release, it's pretty much just his work here in doing the backporting of networking fixes to help resolve "FragmentSmack" (i.e. CVE-2018-5391)." As usual, users of the kernel series should upgrade.

The OpenStack Foundation's 2018 annual report

Friday 8th of February 2019 05:20:08 PM
The OpenStack Foundation has issued its 2018 annual report. "2018 was a productive year for the OpenStack community. A total of 1,972 contributors approved more than 65,000 changes and published two major releases of all components, code named Queens and Rocky. The component project teams completed work on themes related to integrating with other OpenStack components, other OpenStack Foundation Open Infrastructure Projects, and projects from adjacent communities. They also worked on stability, performance, and usability improvements. In addition to that component-specific work, the community continued to expand our OpenStack-wide goals process, using a few smaller topics to refine the goal selection process and understand how best to complete initiatives on such a large scale."

GTK+ renamed to GTK

Friday 8th of February 2019 04:14:20 PM
The GTK+ toolkit project has, after extensive deliberation, decided to remove the "+" from its name. "Over the years, we had discussions about removing the '+' from the project name. The 'plus' was added to 'GTK' once it was moved out of the GIMP sources tree and the project gained utilities like GLib and the GTK type system, in order to distinguish it from the previous, in-tree version. Very few people are aware of this history, and it's kind of confusing from the perspective of both newcomers and even expert users; people join the wrong IRC channel, the URLs on wikis are fairly ugly, etc."

More in Tux Machines

Games: Surviving Mars and OpenMW

Kernel and Security: BPF, Mesa, Embedded World, Kernel Address Sanitizer and More

  • Concurrency management in BPF
    In the beginning, programs run on the in-kernel BPF virtual machine had no persistent internal state and no data that was shared with any other part of the system. The arrival of eBPF and, in particular, its maps functionality, has changed that situation, though, since a map can be shared between two or more BPF programs as well as with processes running in user space. That sharing naturally leads to concurrency problems, so the BPF developers have found themselves needing to add primitives to manage concurrency (the "exchange and add" or XADD instruction, for example). The next step is the addition of a spinlock mechanism to protect data structures, which has also led to some wider discussions on what the BPF memory model should look like. A BPF map can be thought of as a sort of array or hash-table data structure. The actual data stored in a map can be of an arbitrary type, including structures. If a complex structure is read from a map while it is being modified, the result may be internally inconsistent, with surprising (and probably unwelcome) results. In an attempt to prevent such problems, Alexei Starovoitov introduced BPF spinlocks in mid-January; after a number of quick review cycles, version 7 of the patch set was applied on February 1. If all goes well, this feature will be included in the 5.1 kernel.
  • Intel Ready To Add Their Experimental "Iris" Gallium3D Driver To Mesa
    For just over the past year Intel open-source driver developers have been developing a new Gallium3D-based OpenGL driver for Linux systems as the eventual replacement to their long-standing "i965 classic" Mesa driver. The Intel developers are now confident enough in the state of this new driver dubbed Iris that they are looking to merge the driver into mainline Mesa proper.  The Iris Gallium3D driver has now matured enough that Kenneth Graunke, the Intel OTC developer who originally started Iris in late 2017, is looking to merge the driver into the mainline code-base of Mesa. The driver isn't yet complete but it's already in good enough shape that he's looking for it to be merged albeit marked experimental.
  • Hallo Nürnberg!
    Collabora is headed to Nuremberg, Germany next week to take part in the 2019 edition of Embedded World, "the leading international fair for embedded systems". Following a successful first attendance in 2018, we are very much looking forward to our second visit! If you are planning on attending, please come say hello in Hall 4, booth 4-280! This year, we will be showcasing a state-of-the-art infrastructure for end-to-end, embedded software production. From the birth of a software platform, to reproducible continuous builds, to automated testing on hardware, get a firsthand look at our platform building expertise and see how we use continuous integration to increase productivity and quality control in embedded Linux.
  • KASAN Spots Another Kernel Vulnerability From Early Linux 2.6 Through 4.20
    The Kernel Address Sanitizer (KASAN) that detects dynamic memory errors within the Linux kernel code has just picked up another win with uncovering a use-after-free vulnerability that's been around since the early Linux 2.6 kernels. KASAN (along with the other sanitizers) have already proven quite valuable in spotting various coding mistakes hopefully before they are exploited in the real-world. The Kernel Address Sanitizer picked up another feather in its hat with being responsible for the CVE-2019-8912 discovery.
  • io_uring, SCM_RIGHTS, and reference-count cycles
    The io_uring mechanism that was described here in January has been through a number of revisions since then; those changes have generally been fixing implementation issues rather than changing the user-space API. In particular, this patch set seems to have received more than the usual amount of security-related review, which can only be a good thing. Security concerns became a bit of an obstacle for io_uring, though, when virtual filesystem (VFS) maintainer Al Viro threatened to veto the merging of the whole thing. It turns out that there were some reference-counting issues that required his unique experience to straighten out. The VFS layer is a complicated beast; it must manage the complexities of the filesystem namespace in a way that provides the highest possible performance while maintaining security and correctness. Achieving that requires making use of almost all of the locking and concurrency-management mechanisms that the kernel offers, plus a couple more implemented internally. It is fair to say that the number of kernel developers who thoroughly understand how it works is extremely small; indeed, sometimes it seems like Viro is the only one with the full picture. In keeping with time-honored kernel tradition, little of this complexity is documented, so when Viro gets a moment to write down how some of it works, it's worth paying attention. In a long "brain dump", Viro described how file reference counts are managed, how reference-count cycles can come about, and what the kernel does to break them. For those with the time to beat their brains against it for a while, Viro's explanation (along with a few corrections) is well worth reading. For the rest of us, a lighter version follows.

Blacklisting insecure filesystems in openSUSE

The Linux kernel supports a wide variety of filesystem types, many of which have not seen significant use — or maintenance — in many years. Developers in the openSUSE project have concluded that many of these filesystem types are, at this point, more useful to attackers than to openSUSE users and are proposing to blacklist many of them by default. Such changes can be controversial, but it's probably still fair to say that few people expected the massive discussion that resulted, covering everything from the number of OS/2 users to how openSUSE fits into the distribution marketplace. On January 30, Martin Wilck started the discussion with a proposal to add a blacklist preventing the automatic loading of a set of kernel modules implementing (mostly) old filesystems. These include filesystems like JFS, Minix, cramfs, AFFS, and F2FS. For most of these, the logic is that the filesystems are essentially unused and the modules implementing them have seen little maintenance in recent decades. But those modules can still be automatically loaded if a user inserts a removable drive containing one of those filesystem types. There are a number of fuzz-testing efforts underway in the kernel community, but it seems relatively unlikely that any of them are targeting, say, FreeVxFS filesystem images. So it is not unreasonable to suspect that there just might be exploitable bugs in those modules. Preventing modules for ancient, unmaintained filesystems from automatically loading may thus protect some users against flash-drive attacks. If there were to be a fight over a proposal like this, one would ordinarily expect it to be concerned with the specific list of unwelcome modules. But there was relatively little of that. One possible exception is F2FS, the presence of which raised some eyebrows since it is under active development, having received 44 changes in the 5.0 development cycle, for example. Interestingly, it turns out that openSUSE stopped shipping F2FS in September. While the filesystem is being actively developed, it seems that, with rare exceptions, nobody is actively backporting fixes, and the filesystem also lacks a mechanism to prevent an old F2FS implementation from being confused by a filesystem created by a newer version. Rather than deal with these issues, openSUSE decided to just drop the filesystem altogether. As it happens, the blacklist proposal looks likely to allow F2FS to return to the distribution since it can be blacklisted by default. Read more

gitgeist: a git-based social network proof of concept

Are you tired of not owning the data or the platform you use for social postings? I know I am. It's hard to say when I "first" used a social network. I've been on email for about 30 years and one of the early ad-hoc forms of social networks were chain emails. Over the years I was asked to join all sorts of "social" things such as IRC, ICQ, Skype, MSN Messenger, etc. and eventually things like Orkut, MySpace, Facebook, etc. I'll readily admit that I'm not the type of person that happily jumps onto every new social bandwagon that appears on the Internet. I often prefer preserving the quietness of my own thoughts. That, though, hasn't stopped me from finding some meaningfulness participating in Twitter, Facebook, LinkedIn and more recently Google+. Twitter was in fact the first social network that I truly embraced. And it would've remained my primary social network had they not killed their own community by culling the swell of independently-developed Twitter clients that existed. That and their increased control of their API effectively made me look for something else. Right around that time Google+ was being introduced and many in the open source community started participating in that, in some ways to find a fresh place where techies can aggregate away from the noise and sometimes over-the-top nature of Facebook. Eventually I took to that too and started using G+ as my primary social network. That is, until Google recently decided to pull the plug on G+. While Google+ might not have represented a success for Google, it had become a good place for sharing information among the technically-inclined. As such, I found it quite useful for learning and hearing about new things in my field. Soon-to-be-former users of G+ have gone in all sorts of directions. Some have adopted a "c'mon guys, get over it, Facebook is the spot" attitude, others have adopted things like Mastodon, others have fallen back to their existing IDs on Twitter, and yet others, like me, are still looking. Read more