Ubuntu
linux package

dom0 kernel panic - xen_blkbk_unmap+0x5c/0x2f0 [xen_blkback]

Bug #1438677 reported by gdm85 on 2015-03-31

This bug affects 1 person

Affects		Status	Importance	Assigned to	Milestone
	linux (Ubuntu)	Triaged	High	Unassigned

Bug Description

Current stable kernel is affected by an issue that happens when releasing grants. It is a communication issue between dom0 and domU and there is a temptative patch upstream (konrad's tree) that might fix the issue:

https://git.kernel.org/cgit/linux/kernel/git/konrad/xen.git/patch/?id=c43cf3ea838541ea9f066f4f1aa7b197cba6276e (also in attachment)

I have not been able to backport this patch on top of current 3.13.0-48 sources.

When this panic is triggered (on a server for example), there is a complete dom0 kernel crash (as documented by attachment log) with data & services loss.

/proc/version_signature: Ubuntu 3.13.0-48.80-generic 3.13.11-ckt16

Tags:

Revision history for this message

gdm85 (gdm85) wrote on 2015-03-31:

xen_crash_xcrpt.log Edit (9.0 KiB, text/plain)

Revision history for this message

gdm85 (gdm85) wrote on 2015-03-31:

xen-blkback: safely unmap grants in case they are still in use Edit (8.9 KiB, text/plain)

NOTE: this patch is not yet merged to the stable tree, so needs some testing

Revision history for this message

Brad Figg (brad-figg) wrote on 2015-03-31: Missing required logs.

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 1438677

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

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