Bug 1432118 – hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread()

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Bug 1432118 - hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread()

Summary:	hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread()

Status:	CLOSED ERRATA

Aliases:	None

Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	kernel-rt (Show other bugs)
Sub Component:
Version:	7.4
Hardware:	Unspecified Unspecified

Priority	high Severity high
Target Milestone:	rc
Target Release:	---
Assigned To:	John Kacur
QA Contact:	Jiri Kastner
Docs Contact:

URL:
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Keywords:

Depends On:
Blocks:	1353018 1410158
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Reported:	2017-03-14 10:47 EDT by John Kacur
Modified:	2017-08-01 20:25 EDT (History)
CC List:	3 users (show)

See Also:
Fixed In Version:
Doc Type:	If docs needed, set a value
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Story Points:	---
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Environment:
Last Closed:	2017-08-01 15:02:59 EDT
Type:	Bug
Regression:	---
Mount Type:	---
Documentation:	---
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Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread() (2.14 KB, patch) 2017-03-14 11:00 EDT, John Kacur	no flags	Details \| Diff
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2017:2077	normal	SHIPPED_LIVE	Important: kernel-rt security, bug fix, and enhancement update	2017-08-01 14:13:37 EDT

Groups: None (edit)

Description John Kacur 2017-03-14 10:47:22 EDT

do_set_cpus_allowed() is not safe vs ->sched_class change.

crash> bt
PID: 11676  TASK: ffff88026f979da0  CPU: 22  COMMAND: "sync_unplug/22"
 #0 [ffff880274d25bc8] machine_kexec at ffffffff8103b41c
 #1 [ffff880274d25c18] crash_kexec at ffffffff810d881a
 #2 [ffff880274d25cd8] oops_end at ffffffff81525818
 #3 [ffff880274d25cf8] do_invalid_op at ffffffff81003096
 #4 [ffff880274d25d90] invalid_op at ffffffff8152d3de
    [exception RIP: set_cpus_allowed_rt+18]
    RIP: ffffffff8109e012  RSP: ffff880274d25e48  RFLAGS: 00010202
    RAX: ffffffff8109e000  RBX: ffff88026f979da0  RCX: ffff8802770cb6e8
    RDX: 0000000000000000  RSI: ffffffff81add700  RDI: ffff88026f979da0
    RBP: ffff880274d25e78   R8: ffffffff816112e0   R9: 0000000000000001
    R10: 0000000000000001  R11: 0000000000011940  R12: ffff88026f979da0
    R13: ffff8802770cb6d0  R14: ffff880274d25fd8  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #5 [ffff880274d25e60] do_set_cpus_allowed at ffffffff8108e65f
 #6 [ffff880274d25e80] sync_unplug_thread at ffffffff81058c08
 #7 [ffff880274d25ed8] kthread at ffffffff8107cad6
 #8 [ffff880274d25f50] ret_from_fork at ffffffff8152bbbc
crash> task_struct ffff88026f979da0 | grep class
  sched_class = 0xffffffff816111e0 <fair_sched_class+64>,

Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

Comment 2 John Kacur 2017-03-14 11:00 EDT

Created attachment 1262994 [details]
hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread()

Comment 4 John Kacur 2017-04-20 19:51:14 EDT

Fixed with 483aacae4cc1

Comment 7 errata-xmlrpc 2017-08-01 15:02:59 EDT

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2017:2077

Comment 8 errata-xmlrpc 2017-08-01 20:25:36 EDT

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2017:2077

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