Dirty Cow vulnerability

Bill.Thomson · 2016-10-27T14:26:20.476Z

Dirty Cow (Copy On Write) affects anyone using any variant of Linux, including Android.

Here’s a couple of links with more info:

How Bad Is Dirty COW? - Linux.com

“Dirty COW” is a serious Linux kernel vulnerability that was recently discovered to have been lurking in the code for more than nine years. It is pretty much guaranteed that if you’re using any version of Linux or Android released in the past decade,...

xda-developers – 26 Oct 16

9 Year Old Linux Kernel bug dubbed 'Dirty Cow' can Root every version of Android

Dirty Cow is a newly discovered, but 9-year-old bug that can be exploited to grant root access on all versions of Android.

Jon · 2016-10-27T14:45:25.270Z

more info (from spongebob?!?):

github.com/raspberrypi/linux

CVE-2016-5195: Dirty COW

opened 07:40AM - 21 Oct 16 UTC

closed 11:20AM - 18 May 17 UTC

silberzwiebel

Hi, I'm running raspbian jessie with ``` Linux pi 3.18.0-trunk-rpi #1 PREEMPT …Debian 3.18.5-1~exp1+rpi19 (2015-08-08) armv6l GNU/Linux ``` I'm unsure whether this protects me from the recently discovered security relevant bug CVE-2016-5195 (aka dirty COW, [debian bug](https://security-tracker.debian.org/tracker/CVE-2016-5195), [more information](http://dirtycow.ninja/)), since the debian bug does not list the kernel version I am running. Could you give information what kernel version is not affected? Many thanks, silberzwiebel

pb66 · 2016-10-27T16:17:44.876Z

You can check the kernel version on the admin page of emoncms or using uname -r at the command prompt of other (non-emoncms server) Pi’s. The patch is applied from 4.4.26-v7+.

Although apparently just

sudo apt-get update
sudo apt-get dist-upgrade

will do, the official advice from the foundation is to use

sudo apt-get update
sudo apt-get install raspberrypi-kernel

…AND REBOOT!!

The new kernel will not get loaded until it is restarted.

This assumes a Raspbian OS image, I haven’t looked into any others.

Raspberry Pi – 25 Oct 16

Fix Dirty COW on the Raspberry Pi - Raspberry Pi

Hi gang, Rob from The MagPi here. We have a new issue out on Thursday but before that, here comes a PSA. You may have seen the news recently about a bug in the Linux kernel called Dirty COW – it’s a vulnerability that affects the ‘copy-on-write’...

Estimated reading time: 1 minute

glyn.hudson · 2016-10-27T16:26:11.867Z

I can confirm that just

sudo apt-get update
sudo apt-get dist-upgrade

Will get you 4.4.26-v7+ on our emonPi Jessie image,and it doesn’t break anything!

Jon · 2016-10-27T18:00:29.422Z

to get the current OS version:
~~to get the current Linux version for the emonPi image~~
Log In > go to the Setup menu > click on Administration. Scroll down to Server Information, then look for the Server OS line.

Screen Shot 2016-10-27 at 12.53.16 PM.png2216×1252 186 KB

Paul · 2016-10-27T18:38:35.767Z

Jon:

to get the current Linux version for the emonPi image:

Applies to all current versions of emoncms.

Paul

Jon · 2016-10-27T18:40:52.798Z

Paul:

Applies to all current versions of emoncms.

Darn! I wanted to be special because I have an emonPi ;-).

Paul · 2016-10-27T19:24:04.934Z

It seems that self-builds are more special Jon - they get a more recent update…

Paul

Jon · 2016-10-27T22:00:44.562Z

I was watching the dist-upgrade commands scroll by (kinda like watching paint dry) and I saw rpikernelhack. From searching The Internet it seems OK and are Linux patches for RaspPi.

Is this really OK? I don’t remember seeing this before.

Adding 'diversion of /boot/overlays/dwc2.dtbo to /usr/share/rpikernelhack/overlays/dwc2.dtbo by rpikernelhack'
Adding 'diversion of /boot/overlays/enc28j60.dtbo to /usr/share/rpikernelhack/overlays/enc28j60.dtbo by rpikernelhack'
Adding 'diversion of /boot/overlays/gpio-ir.dtbo to /usr/share/rpikernelhack/overlays/gpio-ir.dtbo by rpikernelhack'
Adding 'diversion of /boot/overlays/gpio-poweroff.dtbo to /usr/share/rpikernelhack/overlays/gpio-poweroff.dtbo by rpikernelhack'
Adding 'diversion of /boot/overlays/hifiberry-amp.dtbo to /usr/share/rpikernelhack/overlays/hifiberry-amp.dtbo by rpikernelhack'

glyn.hudson · 2016-10-27T22:55:15.987Z

raspberrypi.stackexchange.com

What is rpikernelhack?

kernel, apt

asked by MD-7 on 06:45PM - 18 Jul 16 UTC

Nothing to worry about

It’s just the directory name given by the developers who have created a Raspberry Pi specific set of patches to the Linux kernel.

Paul_Cardelli · 2016-10-29T06:01:00.626Z

anything special I need to do when updating the kernal with the root on an external USB Hard drive?

Just saying cause I ended up with a rainbow screen. I’ll check a few things out. Maybe the new kernel.img file was corrupt.

Bill.Thomson · 2016-10-29T11:51:22.976Z

What distro / version are you running?

Paul_Cardelli · 2016-10-29T14:09:19.133Z

I was running the pre built emonSD-03May16, which I had migrated to my external USB HD, and made read-write able.

I tried changing the cmdline.txt to boot from the SD card, but got the same rainbow screen. Maybe I can reflash my SDcard and start over and recover my 15 days of data on my HDD. I’m going to try and test my PI3 with an image I have on my other PI2 for something else.

Bill.Thomson · 2016-10-29T16:04:20.313Z

Paul_Cardelli:

I’m going to try and test my PI3 with an image I have on my other PI2 for something else.

Run sudo apt-get update && sudo apt-get upgrade (provided it’s Raspbian, or a derivative) on the card that you pull from your Pi2. Otherwise, you’ll definitely get the rainbow…

Did you do the apt-get update/upgrade on your HDD? That should have been all that was needed.

Paul_Cardelli · 2016-10-29T16:21:25.086Z

can’t get it to boot from the hard drive or SD card at this point

Bill.Thomson · 2016-10-29T16:23:30.655Z

Is the “rainbow” a small square in the upper right corner of your screen?
Or is it the large one that occupies most of the screen?

Paul_Cardelli · 2016-10-29T17:44:17.581Z

not sure what happened. Looks like I did not move the data folder off the SD card, so I’m in the process of getting that to the HD. I did have to build a new SD card, and copy the old cmdline.txt from the old SD card to get it to boot past the rainbow colors. This seems to be working, and the HD booted with everything but my data folder which was still mounting to the SD card.

So once I get stable again I’ll check my version and make sure it was jsut the SD card giving me grief, and likely due to using one of those cheep Samsung 32GB cards I had laying around. I keep forgetting why I hate them. Probably only good for pictures.