All posts by corbet

[$] Ripples from Stack Clash

Post Syndicated from corbet original https://lwn.net/Articles/726580/rss

In one sense, the Stack Clash vulnerability
that was announced on June 19 has not had a huge impact: thus far, at
least, there have been few (if any) stories of active exploits in the
wild. At other levels, though, this would appear to be in important
vulnerability, in that it has raised a number of questions about how the
community handles security issues and what can be expected in the future.
The indications, unfortunately, are not all positive.

[$] daxctl() — getting the other half of persistent-memory performance

Post Syndicated from corbet original https://lwn.net/Articles/726481/rss

Persistent memory promises high-speed, byte-addressable access to storage,
with consequent benefits for all kinds of applications. But realizing those
benefits has turned out to present a number of challenges for the Linux
kernel community. Persistent memory is neither ordinary memory nor
ordinary storage,
so traditional approaches to memory and storage are not always well suited
to this new world. A proposal for a new daxctl() system call,
along with the ensuing discussion, shows how hard it can be to get the most
out of persistent memory.

[$] ProofMode: a camera app for verifiable photography

Post Syndicated from corbet original https://lwn.net/Articles/726142/rss

The default apps on a mobile platform like Android are familiar targets for
replacement, especially for developers concerned about security. But while
messaging and voice apps (which can be replaced by Signal and Ostel, for
instance) may be the best known examples, the non-profit Guardian Project has taken up the
cause of improving the security features of the camera app. Its latest
such project is ProofMode, an app
to let users take photos and videos that can be verified as authentic by
third parties.

Vranken: The OpenVPN post-audit bug bonanza

Post Syndicated from corbet original https://lwn.net/Articles/726157/rss

Guido Vranken describes
his efforts to fuzz-test OpenVPN and the bug reports that resulted.
“Most of this issues were found through fuzzing. I hate admitting it,
but my chops in the arcane art of reviewing code manually, acquired through
grueling practice, are dwarfed by the fuzzer in one fell swoop; the
mortal’s mind can only retain and comprehend so much information at a time,
and for programs that perform long cycles of complex, deeply nested
operations it is simply not feasible to expect a human to perform an
encompassing and reliable verification.”

A Stack Clash disclosure post-mortem

Post Syndicated from corbet original https://lwn.net/Articles/726137/rss

For those who are curious about how the community deals with a serious
vulnerability, Solar Designer’s description of the embargo process around
the “Stack Clash” issue (and his unhappiness with it) is worth
a read. “Qualys first informed the distros list about this upcoming set of issues
on May 3. This initial notification didn’t say Stack Clash nor anything
like that, but merely expressed intent to disclose the issues and
concern that the list’s maximum embargo duration of 14 to 19 days might
not be sufficient in this case. In the resulting discussion, I agreed
to consider extending the embargo beyond list policy should there be
convincing reasons for that. In retrospect, I think I shouldn’t have
agreed to that.”

Raffeiner: My Ubuntu for mobile devices post mortem analysis

Post Syndicated from corbet original https://lwn.net/Articles/726034/rss

Simon Raffeiner describes
in detail the reasons he sees for the failure of the Ubuntu phone
project.
“I understand there weren’t enough developers to fix everything at
once, but instead of deciding to either make a good phone OR a good tablet
with Convergence, we had devices which couldn’t really do anything
right. The whole project also always always had this ‘these are developer
devices, it’s not important to do it fast, we will win in the long run’ air
around it – until the management quite obviously realised that this was all
way too expensive and too much time had already been lost.”

The casync filesystem image distribution tool

Post Syndicated from corbet original https://lwn.net/Articles/726005/rss

Lennart Poettering announces
casync, a tool for distributing system images.
“casync takes inspiration from the popular rsync file synchronization
tool as well as the probably even more popular git revision control
system. It combines the idea of the rsync algorithm with the idea of
git-style content-addressable file systems, and creates a new system for
efficiently storing and delivering file system images, optimized for
high-frequency update cycles over the Internet. Its current focus is on
delivering IoT, container, VM, application, portable service or OS images,
but I hope to extend it later in a generic fashion to become useful for
backups and home directory synchronization as well.”

[$] Attacking the kernel via its command line

Post Syndicated from corbet original https://lwn.net/Articles/725860/rss

The kernel’s command line allows the specification of many operating
parameters at boot time. A silly bug in command-line parsing was reported
by Ilya Matveychikov on May 22; it can be exploited to force a stack
buffer overflow with a controlled payload that can overwrite memory. The
bug itself stems from a bounds-checking error that, while simple, has still
been in the Linux kernel source since version 2.6.20. The subsequent
disclosure post by
Matveychikov in the oss-security list spawned a discussion on what
constitutes a vulnerability, and what is, instead, merely a bug.

Schaller: Fedora Workstation 26 and beyond

Post Syndicated from corbet original https://lwn.net/Articles/725992/rss

Christian Schaller has posted an
extensive look forward at the changes coming to the Fedora desktop.
“Another major project we been working on for a long time in Fleet
Commander. Fleet Commander is a tool to allow you to manage Fedora and RHEL
desktops centrally. This is a tool targeted at for instance Universities or
companies with tens, hundreds or thousands of workstation installation. It
gives you a graphical browser based UI (accessible through Cockpit) to
create configuration profiles and deploy across your organization.”

[$] Preventing stack guard-page hopping

Post Syndicated from corbet original https://lwn.net/Articles/725832/rss

Normally, the -rc6 kernel testing release is not the place where one would
expect to find a 900-line memory-management change. As it happens, though,
such a change was quietly merged immediately prior to the 4.12-rc6 release; indeed, it may have been the
real reason behind 4.12-rc6 coming out some hours later than would have
been expected. This change is important, though, in that it addresses a
newly publicized security threat that, it seems, is being actively
exploited.

[$] User-space access to WMI functions

Post Syndicated from corbet original https://lwn.net/Articles/725725/rss

Windows Management Instrumentation (WMI) is a vaguely defined mechanism for
the control of platform-specific devices; laptop functions like special
buttons, LEDs, and the backlight are often controlled through WMI
interfaces. On Linux, access to WMI functions is restricted to the kernel,
while Windows allows user space to use them as well. A recent proposal to
make WMI functions available to user space in Linux as well spawned a
slow-moving conversation that turned on a couple of interesting questions —
only one of which was anticipated in the proposal itself.

Kernel prepatch 4.12-rc6

Post Syndicated from corbet original https://lwn.net/Articles/725787/rss

The 4.12-rc6 kernel prepatch is out for
testing. “The good news is that rc6 is smaller than rc5 was, and I think we’re
back on track and rc5 really was big just due to random timing. We’ll
see. Next weekend when I’m back home and do rc7, I’ll see how I feel
about things. I’m still hopeful that this would be a normal release
cycle where rc7 is the last rc.”

AIMS Desktop 2017.1 released

Post Syndicated from corbet original https://lwn.net/Articles/725712/rss

The AIMS desktop is a
Debian-derived distribution aimed at mathematical and scientific use. This
project’s first public release, based on Debian 9, is now available.
It is a GNOME-based distribution with a bunch of add-on software.
“It is maintained by AIMS (The African Institute for Mathematical
Sciences), a pan-African network of centres of excellence enabling Africa’s
talented students to become innovators driving the continent’s scientific,
educational and economic self-sufficiency.”

Debian 9 “Stretch” released

Post Syndicated from corbet original https://lwn.net/Articles/725696/rss

The Debian 9 “Stretch” release is now available. “Debian 9 is
dedicated to the project’s founder Ian Murdock, who passed away on 28
December 2015.” There are a lot of changes in this release,
including a switch to MariaDB, the return of Firefox and Thunderbird under
those names, 90% reproducible-build coverage, a rootless X server, and
more.