| 2018-10-31 14:20:06 |
bugproxy |
bug |
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added bug |
| 2018-10-31 14:20:08 |
bugproxy |
tags |
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architecture-s39064 bugnameltc-172752 severity-high targetmilestone-inin1810 |
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| 2018-10-31 14:20:09 |
bugproxy |
ubuntu: assignee |
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Skipper Bug Screeners (skipper-screen-team) |
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| 2018-10-31 14:20:14 |
bugproxy |
affects |
ubuntu |
linux (Ubuntu) |
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| 2018-10-31 14:21:36 |
Frank Heimes |
bug task added |
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ubuntu-z-systems |
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| 2018-10-31 14:21:44 |
Frank Heimes |
ubuntu-z-systems: importance |
Undecided |
High |
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| 2018-10-31 14:22:05 |
Frank Heimes |
ubuntu-z-systems: assignee |
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Canonical Kernel Team (canonical-kernel-team) |
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| 2018-10-31 14:22:47 |
Frank Heimes |
ubuntu-z-systems: status |
New |
Triaged |
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| 2018-10-31 17:28:36 |
Joseph Salisbury |
linux (Ubuntu): importance |
Undecided |
High |
|
| 2018-10-31 17:28:40 |
Joseph Salisbury |
linux (Ubuntu): status |
New |
Triaged |
|
| 2018-10-31 17:28:43 |
Joseph Salisbury |
linux (Ubuntu): assignee |
Skipper Bug Screeners (skipper-screen-team) |
Joseph Salisbury (jsalisbury) |
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| 2018-10-31 17:30:31 |
Joseph Salisbury |
nominated for series |
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Ubuntu Cosmic |
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| 2018-10-31 17:30:31 |
Joseph Salisbury |
bug task added |
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linux (Ubuntu Cosmic) |
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| 2018-10-31 17:30:31 |
Joseph Salisbury |
nominated for series |
|
Ubuntu Xenial |
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| 2018-10-31 17:30:31 |
Joseph Salisbury |
bug task added |
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linux (Ubuntu Xenial) |
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| 2018-10-31 17:30:31 |
Joseph Salisbury |
nominated for series |
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Ubuntu Bionic |
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| 2018-10-31 17:30:31 |
Joseph Salisbury |
bug task added |
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linux (Ubuntu Bionic) |
|
| 2018-10-31 17:30:39 |
Joseph Salisbury |
linux (Ubuntu Xenial): status |
New |
Triaged |
|
| 2018-10-31 17:30:42 |
Joseph Salisbury |
linux (Ubuntu Bionic): status |
New |
Triaged |
|
| 2018-10-31 17:30:46 |
Joseph Salisbury |
linux (Ubuntu Cosmic): status |
New |
Triaged |
|
| 2018-10-31 17:30:49 |
Joseph Salisbury |
linux (Ubuntu Xenial): importance |
Undecided |
High |
|
| 2018-10-31 17:30:50 |
Joseph Salisbury |
linux (Ubuntu Bionic): importance |
Undecided |
High |
|
| 2018-10-31 17:30:53 |
Joseph Salisbury |
linux (Ubuntu Cosmic): importance |
Undecided |
High |
|
| 2018-10-31 17:31:43 |
Joseph Salisbury |
linux (Ubuntu Xenial): assignee |
|
Joseph Salisbury (jsalisbury) |
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| 2018-10-31 17:31:46 |
Joseph Salisbury |
linux (Ubuntu Bionic): assignee |
|
Joseph Salisbury (jsalisbury) |
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| 2018-10-31 17:31:49 |
Joseph Salisbury |
linux (Ubuntu Cosmic): assignee |
|
Joseph Salisbury (jsalisbury) |
|
| 2018-10-31 17:36:00 |
Joseph Salisbury |
linux (Ubuntu Cosmic): status |
Triaged |
Fix Released |
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| 2018-10-31 17:43:42 |
Joseph Salisbury |
linux (Ubuntu Xenial): status |
Triaged |
Fix Released |
|
| 2018-10-31 17:43:44 |
Joseph Salisbury |
linux (Ubuntu Bionic): status |
Triaged |
In Progress |
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| 2018-10-31 17:45:48 |
Joseph Salisbury |
linux (Ubuntu): status |
Triaged |
Fix Released |
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| 2018-10-31 19:06:02 |
Frank Heimes |
ubuntu-z-systems: status |
Triaged |
Fix Committed |
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| 2018-11-01 15:24:01 |
Frank Heimes |
description |
Description: kvm: fix deadlock when killed by oom
Symptom: oom killer leaves processes in a deadlock state.
Problem: The problem arises in the rare cases in which
handle_mm_fault does not release the mm_sem.
Solution: Correct the issue by manually relaese the mm_sem
when needed.
Reproduction: Create numerous KVM guests so that the host starts
swapping and memory becomes overcomitted and the oom
killer is triggered.
kernel 4.19
Upstream-ID: 306d6c49ac9ded11114cb53b0925da52f2c2ada1 |
== SRU Justification ==
Description: kvm: fix deadlock when killed by oom
Symptom: oom killer leaves processes in a deadlock state.
Problem: The problem arises in the rare cases in which
handle_mm_fault does not release the mm_sem.
Solution: Correct the issue by manually release the mm_sem when needed.
== Fix ==
306d6c49ac9ded11114cb53b0925da52f2c2ada1 ("s390/kvm: fix deadlock when killed by oom")
== Patch ==
commit 306d6c49ac9ded11114cb53b0925da52f2c2ada1
Author: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Date: Mon Jul 16 10:38:57 2018 +0200
s390/kvm: fix deadlock when killed by oom
When the oom killer kills a userspace process in the page fault handler
while in guest context, the fault handler fails to release the mm_sem
if the FAULT_FLAG_RETRY_NOWAIT option is set. This leads to a deadlock
when tearing down the mm when the process terminates. This bug can only
happen when pfault is enabled, so only KVM clients are affected.
The problem arises in the rare cases in which handle_mm_fault does not
release the mm_sem. This patch fixes the issue by manually releasing
the mm_sem when needed.
Fixes: 24eb3a824c4f3 ("KVM: s390: Add FAULT_FLAG_RETRY_NOWAIT for guest fault")
Cc: <stable@vger.kernel.org> # 3.15+
Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
== Regression Potential ==
Low and minimal, because:
- code change is s390x only
- limited to one single file: /arch/s390/mm/fault.c
- just two additional lines added (if stmt)
- Xenial and Cosmic already have this commit via upstream stable updates.
- Hence patch is just missing in Bionic.
- Test kernel was build for testting.
== Test Case ==
Create numerous KVM guests so that the host starts swapping
and memory becomes overcomitted and the oom killer is triggered.
__________
Description: kvm: fix deadlock when killed by oom
Symptom: oom killer leaves processes in a deadlock state.
Problem: The problem arises in the rare cases in which
handle_mm_fault does not release the mm_sem.
Solution: Correct the issue by manually relaese the mm_sem
when needed.
Reproduction: Create numerous KVM guests so that the host starts
swapping and memory becomes overcomitted and the oom
killer is triggered.
kernel 4.19
Upstream-ID: 306d6c49ac9ded11114cb53b0925da52f2c2ada1 |
|
| 2018-11-08 05:36:29 |
Khaled El Mously |
linux (Ubuntu Bionic): status |
In Progress |
Fix Committed |
|
| 2018-11-15 11:35:08 |
Brad Figg |
tags |
architecture-s39064 bugnameltc-172752 severity-high targetmilestone-inin1810 |
architecture-s39064 bugnameltc-172752 severity-high targetmilestone-inin1810 verification-needed-bionic |
|
| 2018-11-20 18:36:52 |
Frank Heimes |
tags |
architecture-s39064 bugnameltc-172752 severity-high targetmilestone-inin1810 verification-needed-bionic |
architecture-s39064 bugnameltc-172752 severity-high targetmilestone-inin1810 verification-done-bionic |
|
| 2018-12-03 14:01:15 |
Launchpad Janitor |
linux (Ubuntu Bionic): status |
Fix Committed |
Fix Released |
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| 2018-12-03 14:01:15 |
Launchpad Janitor |
cve linked |
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2018-18955 |
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| 2018-12-03 15:54:40 |
Frank Heimes |
ubuntu-z-systems: status |
Fix Committed |
Fix Released |
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| 2019-07-24 20:56:52 |
Brad Figg |
tags |
architecture-s39064 bugnameltc-172752 severity-high targetmilestone-inin1810 verification-done-bionic |
architecture-s39064 bugnameltc-172752 cscc severity-high targetmilestone-inin1810 verification-done-bionic |
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