kernel 3.11.0-13 freezes on qemu+kvm VM start

This change was made by a bot.

I'd like to perform a bisect to figure out what commit caused this regression. We need to identify the earliest kernel where the issue started happening as well as the latest kernel that did not have this issue.

Can you test the following kernels and report back? We are looking for the first kernel version that exhibits this bug:

v3.11.4: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.4-saucy/
v3.11.5: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.5-saucy/
v3.11.6: http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11.6-saucy/

You don't have to test every kernel, just up until the kernel that first has this bug.

Thanks in advance!

I've done the test,

crash occurs when running kernel v3.11.5

And the bug does not exist with v3.11.4? If that is the case, I will start a kernel bisect between v3.11.4 and v3.11.5. The bisect will require testing of about 7 - 10 kernels, but it will identify the commit that introduced this regression.

Yup, I did as you suggested, booting with v3.11.4 is OK then booting with v3.11.5 triggers the crash

I started a kernel bisect between v3.11.4 and v3.11.5 The kernel bisect will require testing of about 7-10 test kernels.

I built the first test kernel, up to the following commit:
698dc640e9dc5722d8ce4bf34524986ef5236390

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

Just did the test, that 3.11.4-031104 kernel cashes too

I built the next test kernel, up to the following commit:
a1c008db75b819e29a62ff3fbeffe493bf7ece93

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

kernel 3.11.4-031104-generic_3.11.4-031104.201311151145 crashes too, a bit differently tough.

first time I try to start the VM the system didn't crash but the VM doesn't start, then I had to kill the Virtual Machine Manager since it became unresponsive.

Then I try to restart the VM again and then the whole system freezes

I built the next test kernel, up to the following commit:
f6dbceef21f13dc27e9b51a2ff372072fee962a4

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

kernel 3.11.4-031104-generic_3.11.4-031104.201311181320 is fine, no crash, in fact I'm using it right now

I built the next test kernel, up to the following commit:
120edba7e46f928b7fd13b40ede405bbd6a1b290

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

kernel 3.11.4-031104-generic_3.11.4-031104.201311201241 crashes

I built the next test kernel, up to the following commit:
1bc5d1065ee4ed31bc6632d707118e5d7bafdf57

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

kernel 3.11.4-031104-generic_3.11.4-031104.201311221255 is running fine, I'm using it right now

I built the next test kernel, up to the following commit:
0e308361d7ca0bf8b23fd472b90aae0fb10a1c32

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

kernel 3.11.4-031104-generic_3.11.4-031104.201311251415 is running fine, I'm using it right now

I built the next test kernel, up to the following commit:
6a0cacf7e1ddc3669019f260ab86f11024a73ce3

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not. I will build the next test kernel based on your test results.

Thanks in advance

kernel 3.11.4-031104-generic_3.11.4-031104.201311271213 is running fine

The bisect identified the following as the first bad commit:

commit 120edba7e46f928b7fd13b40ede405bbd6a1b290
Author: Hong Zhiguo <email address hidden>
Date: Sat Sep 14 22:42:28 2013 +0800

bridge: fix NULL pointer deref of br_port_get_rcu

I built a test kernel with that commit reverted.

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not.

kernel 3.11.0-14-generic_3.11.0-14.21~lp1249880Commit120edba7Reverted works fine, VM doesn't crash the system on start

Thanks for testing! I'll send a message upstream to the patch author and request some feedback.

We received a patch from upstream.

I built a Saucy test kernel with the patch applied.

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1249880

Can you test that kernel and report back if it has the bug or not?

Thanks again for all the help testing!

3.11.0-15-generic_3.11.0-15.22~lp1249880Patched doesn't work well.

the moment I start my VM the system become unresponsible. A bit different than with 3.11.0-13 tough, the mouse still moves around, but you can't do anything, the whole desktop is in a frozen state.

on a side note just released kernel 3.11.0-14 freezes the whole computer.

I updated upstream with your testing results.

Could you also give the latest mainline kernel a test, to see if it also exhibits this bug? It can be downloaded from:

http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.13-rc7-trusty/

3.13.0-031300rc7-generic_3.13.0-031300rc7.201401041835 works fine, I don't experienced crashes

However I can't use it as is since it lacks a proper NVidia driver link and I can't use my dual-screen, plus I must start manually my WindowManager since it doesn't start correctly after X loads.

But for booting up the system and running VM it works fine.

Thanks for testing. That means a fix for this bug is in the mainline kernel. I'll check with upstream and see if the fix for this was cc'd to stable.

This bug was nominated against a series that is no longer supported, ie saucy. The bug task representing the saucy nomination is being closed as Won't Fix.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.