Random Kernel Oops after graphical log in
 

Dear all,

this problem keeps me up for over a week now and I have to admit it is over my head.
I have Linux running on my computer for some years now. Suddently it produces Kernel Oopses in two out of three boots which make the PC unusable. They always appear in different tasks, also the "Comm"-entry is always different. Interestingly this always appears after graphical log in, never when I log in to one of the virtual consoles (ctrl+alt+F1). It is also quite funny that the system is absolutely stable once I get past the (late) booting stage.

What I have tried so far:
- Reinstalled my distribution (Debian Jessie)
- Updated the kernel from the backport repository: linux-image-3.16.0-4-amd64 --> 4.6.0-0.bpo.1-amd64
- installed packages amd64-microcode, firmware-linux, firmware-linux-free, firmware-linux-nonfree
- (also experienced a crash from a (a bit older) Mint Live USB-stick)
- Blacklisted snd_hda_intel (I thought it might have been a conflict between suond and hdmi sound)
- Performed a memtest68+, passed two times (once with, once without SMP)

I was thinking it looks like a hardware issue, because I even newly installed the system. On the other hand, as I said, when getting past the booting everything is working stable. Also it is always the same point in time, shortly after logging into the graphical user interface.
Any ideas? I am quite desperate.

Best, Gerrit





PS: you can get my complete logs here:
https://www.dropbox.com/sh/7i784bfow...sfgZPyk0a?dl=0

It looks to me like a memory corruption issue. It can be caused by many different things. Good that you have eliminated memory - this is one of the first things to test.

I would have the following suggestions to you:
* enable some kernel debugging options if you're ready to recompile your kernel. The kernel has (in Kernel debugging) automatic verification routines for different structures. If it's for example a corruption caused by a driver, it will be easier to find out.
* try to remove some of your hardware and check if the problem is still present: USB devices, unneeded peripherals, maybe you can replace your graphics card and test with another one etc

Thank you for your quick reply.

Weeell... sounds frightening. If you maybe could hold my hand when I am doing this?

But, seriously, sounds like something I can learn a lot from. And maybe I could actually help find a bug :) So I'll start with your second suggestion. Could you maybe point me to a good tutorial for compiling the kernel?

Found it! The bad guy was a very, very, very old TV-card that I actually did not even use nor have ever used. The model is:

Cinergy 400 TV, Terratec

I decided that recompiling the kernel is something I would really like to do at one point in my life but right now is not the right time because I think I have to learn a lot of stuff in advance.
Still, do you think I should file a bug report somewhere? I am not sure what driver caused it but i would guess it was the sound driver. I never filed a bug report so could you point me to where I should do this?

PS: I found this page:
https://www.mythtv.org/wiki/Terratec_Cinergy_400

If you never used the card nor plan to use it then why not move on. If you plan to use it then you just need to install the module for that card. What linux?