Bug 1342874

Summary:	Owner and SElinux context cannot be restored after hot-unplug USB Host device
Product:	Red Hat Enterprise Linux 7	Reporter:	Pei Zhang <pzhang>
Component:	libvirt	Assignee:	Ján Tomko <jtomko>
Status:	CLOSED ERRATA	QA Contact:	Virtualization Bugs <virt-bugs>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	7.3	CC:	dyuan, jtomko, lmen, mzhan, rbalakri, xuzhang
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	libvirt-2.0.0-1.el7	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-11-03 18:46:27 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Pei Zhang 2016-06-06 03:36:46 UTC

Description of problem:
Owner and SElinux context cannot be restore after hot-unplug USB Host device.

Version-Release number of selected component (if applicable):
libvirt-1.3.4-1.el7.x86_64
qemu-kvm-rhev-2.6.0-4.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1.Prepared an USB device 
# lsusb
......
Bus 002 Device 006: ID 0951:1656 Kingston Technology DataTraveler Ultimate G2

# ls -alZ /dev/bus/usb/002/006 -alZ
crw-rw-r--. root root system_u:object_r:usb_device_t:s0 /dev/bus/usb/002/006

2. attach this USB device to a running guest.
# cat hostdev-usb3.xml
<hostdev mode='subsystem' type='usb' managed='yes'>
<source startupPolicy='optional'>
	<vendor id='0x0951'/>
	<product id='0x1656'/>
</source>
</hostdev>

# virsh attach-device r72 hostdev-usb3.xml 
Device attached successfully

check Owner and SElinux label
# ls -alZ /dev/bus/usb/002/006 -alZ
crw-rw-r--. qemu qemu system_u:object_r:svirt_image_t:s0:c270,c634 /dev/bus/usb/002/006

3. detach device 
# virsh detach-device r72 hostdev-usb3.xml 
Device detached successfully

check owner and SElinxu label again.

# ls -alZ /dev/bus/usb/002/006
crw-rw-r--. qemu qemu system_u:object_r:svirt_image_t:s0:c270,c634 /dev/bus/usb/002/006

# virsh destroy r72 
Domain r72 destroyed

# ls -alZ /dev/bus/usb/002/006
crw-rw-r--. qemu qemu system_u:object_r:svirt_image_t:s0:c270,c634 /dev/bus/usb/002/006

Actual results:
As step 3, usb device keep the owner and SElinux context as set to virtual machine.

Expected results:
Libvirt should clean what it modified before. After detach device, usb device should be changed back to original permission and SELinux context.

Additional info:
It cannot be reproduced on RHEL7.2.

Comment 2 Ján Tomko 2016-06-17 13:34:24 UTC

Upstream patch:
https://www.redhat.com/archives/libvir-list/2016-June/msg01166.html

Comment 3 Ján Tomko 2016-06-17 17:46:23 UTC

Pushed as:
commit 22d262c9b019ab43bc9ff7188fc31794902d5287
Author:     Ján Tomko <jtomko>
CommitDate: 2016-06-17 19:43:22 +0200

    qemu: restore non-pci hostdev labels after detach
    
    Commit 409de00 changed the logic to only match PCI devices
    while moving this before Remove*HostDevice calls.
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1342874

git describe: v1.3.5-316-g22d262c

Comment 5 lijuan men 2016-08-24 08:26:02 UTC

verify the bug

version:
libvirt-2.0.0-6.el7.x86_64
qemu-kvm-rhev-2.6.0-22.el7.x86_64

steps:

1.Prepared an USB device 
[root@localhost ~]# lsusb
Bus 002 Device 002: ID 0951:1642 Kingston Technology DT101 G2
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

[root@localhost ~]# ls -alZ /dev/bus/usb/002/002
crw-rw-r--. root root system_u:object_r:usb_device_t:s0 /dev/bus/usb/002/002

2. attach this USB device to a running guest
[root@localhost ~]# cat usb.xml 
<hostdev mode='subsystem' type='usb' managed='yes'>
<source startupPolicy='optional'>
	<vendor id='0x0951'/>
	<product id='0x1642'/>
</source>
</hostdev>

[root@localhost ~]# virsh attach-device bios usb.xml 
Device attached successfully


[root@localhost ~]# ls -alZ /dev/bus/usb/002/002
crw-rw-r--. qemu qemu system_u:object_r:svirt_image_t:s0:c152,c690 /dev/bus/usb/002/002

3. detach device 
[root@localhost ~]# virsh detach-device bios usb.xml 
Device detached successfully

[root@localhost ~]# 
[root@localhost ~]# ls -alZ /dev/bus/usb/002/002
crw-rw-r--. root root system_u:object_r:usb_device_t:s0 /dev/bus/usb/002/002

usb device is changed back to original permission and SELinux context.

Comment 7 errata-xmlrpc 2016-11-03 18:46:27 UTC

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://rhn.redhat.com/errata/RHSA-2016-2577.html