# [SOLVED] Kernel panic due to wl (broadcom-sta)

## AaylaSecura

Greetings! I'm having a strange issue - two days ago I installed a few updates (nothing important - xorg-server, sudo and a few others, I can get a list of them later, forgot to do it). The next day when I started the PC and issued startx the system just froze and I had to hard reset it. Afterwards the kernel kept panicking 1-2 seconds after the default runlevel was finished loading. At first I thought it may have been some file corruption due to me not cleanly shutting it down, so I:

 * ran e2fsck -fc <device> - was fine

 * rebuilt all system packages via emerge -e @system

 * removed and reinstalled the kernel sources and rebuilt the kernel image, reinstalled all modules

nothing changed. I then created a minimal runlevel which only had sshd and syslog-ng started and it booted fine. I started each of the other services one by one and the very last one I started, dropbox, printed some PAM related error, which I could not fully read before the kernel panicked. This PAM error was not reproducible, however, the kernel always panics when dropbox is started. I rebuilt dropbox and also reverted all upgrades done two days ago. At this point everything should have been as it was 2 days ago but the problem remained. I wanted to investigate the PAM error a bit more, so I

 * tried su-ing - oddly enough one time it made the kernel panic, another time it did not... su-ing from within a chrooted environment is not a problem

 * tried ssh-ing into the system and although I have UsePAM no in sshd_config it paniced again

I am out of ideas as to how to "debug" this further... Any help greatly appreciated.

P.S. It's ~amd64 system, kernel version is 4.2.5 (4.3.0 does not work with the proprietry nvidia drivers, but I can nevertheless try later to see if it will panic when ssh-ing, starting dropbox, etc)Last edited by AaylaSecura on Wed Nov 04, 2015 12:47 pm; edited 3 times in total

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## Hu

Please post the output from the kernel panic.  You mention that you cannot use 4.3 with the nVidia drivers, which suggests that you are loading out-of-tree proprietary modules.  Please try to reproduce the panic with an untainted kernel.

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## AaylaSecura

 *Hu wrote:*   

> Please post the output from the kernel panic.  You mention that you cannot use 4.3 with the nVidia drivers, which suggests that you are loading out-of-tree proprietary modules.  Please try to reproduce the panic with an untainted kernel.

 

Hi and thanks for replying. I don't really know how to log a kernel panic (otherwise I'd done it)... How do I obtain a full log of it?

The only external modules that I use are the nvidia module which is not loaded until Xorg starts (hence it was not loaded during any of the times the kernel panicked) and wl provided by broadcom-sta. This one is loaded automatically - I'll try to disable it and see what happens.

Edit: would dmesg -w > <some-file> work?

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## AaylaSecura

You were right about the tainted kernel! So I did a few tests and bottom line: ssh-ing from within the system (localhost) works fine but once I load the wl module and ssh into it from another device (or I assume do any network related task, since starting dropbox panics it too) it panics.

For now I've blacklisted the wl module and I can start Xorg just fine. In fact I just re-emerged the latest nvidia drivers for the latest kernel version - that used to fail during configure phase with an "invalid kernel configuration" but now it compiled fine and I am using kernel 4.3 with the latest nvidia drivers. Loading wl ssh-ing still crashes the system under 4.3 as well.

I did dmesg -w > log in the background but the log stops at:

```
[  210.554187] wl: no symbol version for module_layout

[  291.601831] wl: module license 'Mixed/Proprietary' taints kernel.

[  291.601833] Disabling lock debugging due to kernel taint

[  291.604792] systemd-udevd[332]: Network interface NamePolicy= disabled on kernel command line, ignoring.

[  291.628118] systemd-udevd[4035]: Process 'net.sh wlan0 start' failed with exit code 1.

[  291.669604] wlan0: Broadcom BCM43b1 802.11 Hybrid Wireless Controller 6.30.223.271 (r587334)

```

which is the output from loading wl, i.e. not what happens right before the panic.

The question remains, what changed in those two days, broadcom-sta was not updated, so I wouldn't expect re-emerging it to affect the module... At this point I can't have networking...

EDIT: I just synced the tree and saw there is a new revision of broadcom-sta which removes the application of broadcom-sta-6.30.223.271-r1-linux-3.18.patch and now ALL IS FINE. The thing two days ago during those updates, broadcom-sta was also updated and this is what had caused all of this, but I missed the fact it was updated since I did not expect it to be the root of the problem. Thanks for the help.

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