1719083 – VM with "nvdimm" memory will not start successfully when Selinux is enabled

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Bug 1719083 - VM with "nvdimm" memory will not start successfully when Selinux is enabled

Summary: VM with "nvdimm" memory will not start successfully when Selinux is enabled

Keywords:
Status:	CLOSED ERRATA
Alias:	None
Product:	Red Hat Enterprise Linux 8
Classification:	Red Hat
Component:	selinux-policy
Sub Component:
Version:	---
Hardware:	x86_64
OS:	Linux
Priority:	high
Severity:	high
Target Milestone:	rc
Target Release:	8.1
Assignee:	Lukas Vrabec
QA Contact:	Milos Malik
Docs Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+	depends on / blocked

Reported:	2019-06-11 02:57 UTC by jiyan
Modified:	2020-11-14 12:33 UTC (History)
CC List:	13 users (show)
Fixed In Version:	selinux-policy-3.14.3-12.el8
Doc Type:	If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed:	2019-11-05 22:11:44 UTC
Type:	Bug
Target Upstream Version:
Embargoed:
Dependent Products:
Flags:	pm-rhel: mirror+

Attachments	(Terms of Use)

Links
System	ID	Private	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHBA-2019:3547	0	None	None	None	2019-11-05 22:12:01 UTC

Description jiyan 2019-06-11 02:57:46 UTC

Description of problem:
VM with "nvdimm" memory will not start successfully  when Selinux is enabled


Version-Release number of selected component (if applicable):
kernel-4.18.0-80.el8.x86_64
libvirt-5.0.0-9.module+el8.0.1+3240+dc659f51.x86_64
qemu-kvm-3.1.0-27.module+el8.0.1+3253+c5371cb3.x86_64


How reproducible:
100%


Steps to Reproduce:
1. Prepare a shutdown VM with the following conf
# virsh domstate vmq35_801
shut off

# virsh dumpxml vmq35_801
...
  <cpu mode='custom' match='exact' check='partial'>
    ...
    <numa>
      <cell id='0' cpus='0-3' memory='512000' unit='KiB' discard='yes'/>
    </numa>
  </cpu>
...
    <memory model='nvdimm' access='shared'>
      <source>
        <path>/tmp/nvdimm</path>
      </source>
      <target>
        <size unit='KiB'>523264</size>
        <node>0</node>
      </target>
      <address type='dimm' slot='0'/>
    </memory>

# truncate -s 512M /tmp/nvdimm

2. Check selinux and /tmp/nvdimm; then start VM
# getenforce 
Enforcing

# ll -alZ /tmp/nvdimm 
-rw-r--r--. 1 root root system_u:object_r:nfs_t:s0 536870912 Jun 10 22:39 /tmp/nvdimm

# virsh start vmq35_801
error: Failed to start domain vmq35_801
error: internal error: process exited while connecting to monitor: 2019-06-11T02:50:09.651486Z qemu-kvm: -object memory-backend-file,id=memnvdimm0,prealloc=yes,mem-path=/tmp/nvdimm,share=yes,size=536870912,host-nodes=0,policy=bind: unable to map backing store for guest RAM: Permission denied

# cat /var/log/audit/audit.log  |grep nvdimm
type=AVC msg=audit(1560221579.207:2556): avc:  denied  { map } for  pid=22727 comm="qemu-kvm" path="/tmp/nvdimm" dev="0:46" ino=61164750 scontext=system_u:system_r:svirt_t:s0:c86,c380 tcontext=system_u:object_r:nfs_t:s0 tclass=file permissive=0
type=SYSCALL msg=audit(1560221579.207:2556): arch=c000003e syscall=9 success=no exit=-13 a0=7f5d549ff000 a1=20000000 a2=3 a3=11 items=0 ppid=1 pid=22727 auid=4294967295 uid=107 gid=107 euid=107 suid=107 fsuid=107 egid=107 sgid=107 fsgid=107 tty=(none) ses=4294967295 comm="qemu-kvm" exe="/usr/libexec/qemu-kvm" subj=system_u:system_r:svirt_t:s0:c86,c380 key=(null)ARCH=x86_64 SYSCALL=mmap AUID="unset" UID="qemu" GID="qemu" EUID="qemu" SUID="qemu" FSUID="qemu" EGID="qemu" SGID="qemu" FSGID="qemu"

3. Close selinux and then start VM
# setenforce 0

# getenforce 
Permissive

# ll -alZ /tmp/nvdimm 
-rw-r--r--. 1 root root system_u:object_r:nfs_t:s0 536870912 Jun 10 22:39 /tmp/nvdimm

# virsh start vmq35_801
Domain vmq35_801 started

# ll -alZ /tmp/nvdimm 
-rw-r--r--. 1 qemu qemu system_u:object_r:nfs_t:s0 536870912 Jun 10 22:51 /tmp/nvdimm

# cat /var/log/audit/audit.log  |grep nvdimm
type=AVC msg=audit(1560221658.585:2588): avc:  denied  { map } for  pid=22815 comm="qemu-kvm" path="/tmp/nvdimm" dev="0:46" ino=61164750 scontext=system_u:system_r:svirt_t:s0:c280,c457 tcontext=system_u:object_r:nfs_t:s0 tclass=file permissive=1
type=SYSCALL msg=audit(1560221658.585:2588): arch=c000003e syscall=9 success=yes exit=139743207616512 a0=7f18803ff000 a1=20000000 a2=3 a3=11 items=0 ppid=1 pid=22815 auid=4294967295 uid=107 gid=107 euid=107 suid=107 fsuid=107 egid=107 sgid=107 fsgid=107 tty=(none) ses=4294967295 comm="qemu-kvm" exe="/usr/libexec/qemu-kvm" subj=system_u:system_r:svirt_t:s0:c280,c457 key=(null)ARCH=x86_64 SYSCALL=mmap AUID="unset" UID="qemu" GID="qemu" EUID="qemu" SUID="qemu" FSUID="qemu" EGID="qemu" SGID="qemu" FSGID="qemu"

Actual results:
As step-2 and step-3 shows

Expected results:
Vm should start successfully with selinux enabled

Additional info:
In RHEL-7.7, can not reproduce this issue.

# getenforce 
Enforcing

# virsh domstate vmq35_772
shut off

# virsh dumpxml vmq35_772 |grep "<memory" -A10
--
    <memory model='nvdimm' access='shared'>
      <source>
        <path>/tmp/nvdimm</path>
      </source>
      <target>
        <size unit='KiB'>523264</size>
        <node>0</node>
      </target>
      <address type='dimm' slot='0'/>
    </memory>

# ll /tmp/nvdimm -alZ
-rw-r--r--. root root system_u:object_r:nfs_t:s0       /tmp/nvdimm

# virsh start vmq35_772
Domain vmq35_772 started

# ll /tmp/nvdimm -alZ
-rw-r--r--. qemu qemu system_u:object_r:nfs_t:s0       /tmp/nvdimm

Comment 1 Han Han 2019-06-11 04:30:30 UTC

The selinux label type of /tmp/nvdimm is nfs_t. It's very strange. Is your /tmp are mounted nfs?
Could you  please try `setsebool virt_use_nfs 1` and then try it again? This selinux boolean is to allow virt to use nfs.

Comment 2 jiyan 2019-06-11 04:57:54 UTC

Hi hanhan The virt_use_nfs is set to on already.

# getenforce 
Enforcing

# getsebool -a |grep virt_use_nfs
virt_use_nfs --> on

# virsh start vmq35_801
error: Failed to start domain vmq35_801
error: internal error: process exited while connecting to monitor: 2019-06-11T04:54:42.602774Z qemu-kvm: -object memory-backend-file,id=memnvdimm0,prealloc=yes,mem-path=/tmp/nvdimm,share=yes,size=536870912,host-nodes=0,policy=bind: unable to map backing store for guest RAM: Permission denied


And I forgot I mount nfs to /tmp, I have changed the nvdimm file to /mnt, then it can succeed.

# getenforce 
Enforcing

# ll -alZ /mnt/nvdimm 
-rw-r--r--. 1 root root system_u:object_r:default_t:s0 536870912 Jun 11 00:52 /mnt/nvdimm

# virsh dumpxml vmq35_801 |grep mnt
        <path>/mnt/nvdimm</path>

# virsh start vmq35_801
Domain vmq35_801 started

# ll -alZ /mnt/nvdimm 
-rw-r--r--. 1 qemu qemu system_u:object_r:svirt_image_t:s0:c346,c509 536870912 Jun 11 00:55 /mnt/nvdimm

Comment 3 jiyan 2019-06-11 04:58:59 UTC

By the way, for the description in bug, The RHEL-7 also tested on /tmp, which is also used to mount NFS storage. and virt_use_nfs is set to on also.

Comment 23 errata-xmlrpc 2019-11-05 22:11:44 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://access.redhat.com/errata/RHBA-2019:3547

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