Recent content on Linux Kernel Monkey Log
As described previously ,
the Linux kernel security team does not identify or mark or announce any sort
of security fixes that are made to the Linux kernel tree. So how, if the Linux
kernel were to become a CVE Numbering Authority (CNA) and responsible for
issuing CVEs, would the identification of security fixes happen in a way that
can be done by a volunteer staff? This post…
Lots of the CVE world seems to focus on “security bugs” but I’ve found that it
is not all that well known exactly how the Linux kernel security process works.
I gave a
 talk about this back in 2023 
and at other conferences since then, attempting to explain how it works, but I
also thought it would be good to explain this all in writing as it is…
With all of the different Linux kernel stable releases happening (at least 1
stable branch and multiple longterm branches are active at any one point in
time), keeping track of what commits are already applied to what branch, and
what branch specific fixes should be applied to, can quickly get to be a very
complex task if you attempt to do this manually. So I’ve created some…
Despite having a stable release model and cadence since December 2003, Linux
kernel version numbers seem to baffle and confuse those that run across them,
causing numerous groups to mistakenly make versioning statements that are flat
out false. So let’s go into how this all works in detail.
It’s been almost 2 full years since Linux became a CNA (Certificate Numbering
Authority) which
meant that we (i.e. the kernel.org community) are now responsible for issuing
all CVEs for the Linux kernel. During this time, we’ve become one of the
largest creators of CVEs by quantity, going from nothing to number 3 in 2024 to
number 1 in 2025. Naturally, this has…
…the one that emulates your real workload. And for me (and probably many of
you reading this), that would be “build a kernel as fast as possible.” And for
that, I recommend the simple kcbench . 
 I kcbench mentioned it a few years ago, when
 writing about a new workstation 
that Level One Techs set up for me, and I’ve been using that as my…
As was
 recently announced ,
the Linux kernel project has been accepted as a CNA as a CVE Numbering
Authority (CNA) for vulnerabilities found in Linux. 
 This is a trend, of more open source projects taking over the haphazard
assignments of CVEs against their project by becoming a CNA so that no other
group can assign CVEs without their involvment. Here’s the
…
Greg is a Fellow at the Linux Foundation and is responsible for the Linux
kernel stable releases. He is also the maintainer of a variety of different
kernel subsystems (USB, char/misc, tty/serial, driver core, staging, etc.) and
has written a few books and articles about Linux kernel development. 
 Wikipedia entry that is usually very out of date 
 reddit AMA in 2020 
…
As was pointed out 
to us stable kernel maintainers last week, the overflow of the .y
release number was going to happen soon, and our proposed solution for
it (use 16 bits instead of 8), turns out to be breaking a
userspace-visable api. 
 As we can’t really break this, I did a release of the 4.4.256 
and 4.9.256 
releases today that contain nothing but a new…
A recent email thread about
 “Why isn’t the 5.10 stable kernel listed as supported for 6 years yet!” 
on the linux-kernel mailing list ended up generating a bunch of direct emails
to me asking what could different companies and individuals due to help out.
What exactly was I looking for here? 
 Instead of having to respond to private emails with the same…
A number of months ago I did an “Ask Me Anything” 
interview on r/linux on
redit. As part of that, a discussion of the hardware I used came up, and
someone said, “I know someone that can get you a new machine” “get that person
a new machine!” or something like that. 
 Fast forward a few months, and a “beefy” AMD Threadwripper…
Given that the main development workflow for most kernel maintainers is
with email, I spend a lot of time in my email client. For the past few
decades I have used ( mutt ),
but every once in a while I look around to see if there is anything else
out there that might work better. 
 One project that looks promising is ( aerc )
which was started by ( Drew DeVault ).
It is…
As everyone seems to like to put kernel trees up on github for random
projects (based on the crazy notifications I get all the time), I
figured it was time to put up a semi-official mirror of all of the
stable kernel releases on github.com 
 It can be found at: https://github.com/gregkh/linux and I will try to
keep it up to date with the real source of all kernel stable…
I get a lot of questions about people asking me about what stable kernel
should they be using for their product/device/laptop/server/etc. all the
time. Especially given the now-extended length of time that some
kernels are being supported by me and others, this isn’t always a very
obvious thing to determine. So this post is an attempt to write down my
opinions on the…
As many people know, last week there was a court hearing in the
Geniatech vs. McHardy case. This was a case brought claiming a license
violation of the Linux kernel in Geniatech devices in the German court
of OLG Cologne. 
 Harald Welte has written up a
 wonderful summary of the hearing ,
I strongly recommend that everyone go read that first. 
 In Harald’s…
Note 
 This post is based on a whitepaper I wrote at the beginning of 2016 to be used
to help many different companies understand the Linux kernel release model and
encourage them to start taking the LTS stable updates more often. I then used
it as a basis of a presentation I gave at the
 Linux Recipes conference in September 2017 
which can be seen here . 
 With…
I keep getting a lot of private emails about my
 previous post 
about the latest status of the Linux kernel patches to resolve both the
Meltdown and Spectre issues. 
 These questions all seem to break down into two different categories,
“What is the state of the Spectre kernel patches?”, and “Is my machine
vunlerable?” 
 State of the kernel…
By now, everyone knows that something “big” just got announced regarding
computer security. Heck, when the
 Daily Mail does a report on it 
, you know something is bad… 
 Anyway, I’m not going to go into the details about the problems being
reported, other than to point you at the wonderfully written
 Project Zero paper on the issues involved here…
By Greg Kroah-Hartman, Chris Mason, Rik van Riel, Shuah Khan, and Grant Likely 
 The Linux kernel ecosystem of developers, companies and users has been
wildly successful by any measure over the last couple decades. Even
today, 26 years after the initial creation of the Linux kernel, the
kernel developer community continues to grow, with more than 500
different companies and…
Based on the recent Linux Kernel Community Enforcement Statement and
 the article describing the background and what it means 
, here are some Questions/Answers to help clear things up. These are
based on questions that came up when the statement was discussed among
the initial round of over 200 different kernel developers. 
 Q: Is this changing the license of the kernel? 
…
As the 4.13 release has now happened , the merge window for
the 4.14 kernel release is now open. I mentioned
 this many weeks ago , but as the word doesn’t seem to have gotten very
far based on various emails I’ve had recently, I figured I need to say it here
as well. 
 So, here it is officially, 4.14 should be the next LTS kernel that I’ll
be supporting…
As I briefly mentioned a few weeks ago on my G+ page, the plan
is for the 4.9 Linux kernel release to be the next “Long Term Supported”
(LTS) kernel. 
 Last year, at the Linux Kernel Summit, we discussed just how to
pick the LTS kernel. Many years ago, we tried to let everyone know
ahead of time what the kernel version would be, but that caused a lot of
problems…
Now that linux.conf.au is over, there has been a bunch of information
running around about the status of kdbus and the integration of
it with systemd . So, here’s a short summary of what’s going on
at the moment. 
 Lennart Poettering gave a talk about
 kdbus at linux.conf.au. The talk can be viewed here ,
and the slides are here . Go read the slides and watch…
Sometimes you don’t have access to vim’s wonderful xxd 
tool, and you need to use it to generate some .c code based on
a binary file.
This happened to me recently when packaging up the EFI signing tools for Gentoo. 
Adding a build requirement of vim for a single autogenerated file was
not an option for some users, so I created a perl version of the
 xxd -i…
Now that The Linux Foundation is a member of the UEFI.org 
group, I’ve been working on the procedures for how to boot a self-signed
Linux kernel on a platform so that you do not have to rely on any
external signing authority. 
 After digging through the documentation out there, it turns out to be
relatively simple in the end, so here’s a recipe for how I did this,…
As I’ve discussed in the past , I will be selecting one
“longterm stable” kernel release every year, and maintain that kernel
release for at least two years. 
 Despite the fact that the 3.10-stable kernel releases are not slowing
down at all, and there are plenty of pending patches already lined up
for the next few releases, I figured it was a good time to let…
While working on the latest statistics for the yearly Linux Foundation
“Who Writes Linux” paper, I noticed the rate-of-change for the 3.10
kernel release that just happened this weekend: 
 
 Every year I think we can’t go faster, and every year I’m wrong. 
 Note, the “number of employers” row is not correct, I haven’t updated
those…
One common Linux kernel driver issue that I see all the time is a driver
author attempting to create a sysfs file in their code by doing
something like: 
 int my_driver_probe (...) 
 { 
 ... 
 retval = device_create_file ( my_device , & my_first_attribute ); 
 if ( retval ) 
 goto error1 ; 
 retval = device_create_file ( my_device , & my_second_attribute );…
Here’s some thoughts about some hardware I was going to use, hardware I
use daily, and hardware I’ll probably use someday in the future. 
 Thunderbolt is dead, long live Thunderbolt. 
 Seriously, it’s dead, use it as a video interconnect and don’t worry
about anything else. 
 Ok, some more explanation is probably in order… 
 Back in October of…