Re: libvirt and SELlinux 'access denied' in a VM

Juerg Haefliger <juergh@xxxxxxxxx> · Mon, 24 Mar 2014 11:23:11 +0100

On Sat, Mar 22, 2014 at 11:46 AM, Daniel J Walsh <dwalsh@xxxxxxxxxx> wrote:
>
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> On 03/21/2014 10:36 AM, Juerg Haefliger wrote:
> > Hi,
> >
> > I started a VM using the official F20 cloud image, installed libvirt and
> > its dependencies and tried to create a guest but SELinux won't let me:

> >
> > [root@fedora-20 ~]# virsh create mini.xml error: Failed to create domain
> > from mini.xml error: Input/output error
> >
> > [root@fedora-20 ~]# journalctl | tail Mar 21 14:23:06 fedora-20 systemd[1]:

> > SELinux policy denies access. Mar 21 14:23:06 fedora-20
> > systemd-machined[7210]: Failed to start machine scope: Access denied Mar 21
> > 14:23:06 fedora-20 libvirtd[6856]: Input/output error

> >
> > [root@fedora-20 ~]# cat /var/log/libvirt/qemu/mini.log 2014-03-21
> > 14:23:06.740+0000: starting up LC_ALL=C
> > PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin QEMU_AUDIO_DRV=none

> > /usr/bin/qemu-system-x86_64 -name mini -S -machine
> > pc-i440fx-1.6,accel=tcg,usb=off -m 1024 -realtime mlock=off -smp
> > 1,sockets=1,cores=1,threads=1 -uuid 11111111-2890-2015-1f87-cbfa725b1dd3

> > -nographic -no-user-config -nodefaults -chardev
> > socket,id=charmonitor,path=/var/lib/libvirt/qemu/mini.monitor,server,nowait
> > -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown

> > -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device
> > virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x2 2014-03-21
> > 14:23:06.744+0000: shutting down
> >
> >
> > type=VIRT_MACHINE_ID msg=audit(1395412399.728:281): pid=6856 uid=0

> > auid=4294967295 ses=4294967295
> > subj=system_u:system_r:virtd_t:s0-s0:c0.c1023 msg='virt=qemu vm="mini"
> > uuid=11111111-2890-2015-1f87-cbfa725b1dd3
> > vm-ctx=system_u:system_r:svirt_tcg_t:s0:c728,c986

> > img-ctx=system_u:object_r:svirt_image_t:s0:c728,c986 model=selinux
> > exe="/usr/sbin/libvirtd" hostname=? addr=? terminal=? res=success'
> > type=VIRT_MACHINE_ID msg=audit(1395412399.728:282): pid=6856 uid=0

> > auid=4294967295 ses=4294967295
> > subj=system_u:system_r:virtd_t:s0-s0:c0.c1023 msg='virt=qemu vm="mini"
> > uuid=11111111-2890-2015-1f87-cbfa725b1dd3 vm-ctx=107:107 img-ctx=107:107

> > model=dac exe="/usr/sbin/libvirtd" hostname=? addr=? terminal=?
> > res=success' type=USER_AVC msg=audit(1395412399.788:283): pid=1 uid=0
> > auid=4294967295 ses=4294967295  subj=system_u:system_r:init_t:s0 msg='avc:

> > denied  { start } for auid=-1 uid=-1 gid=-1
> > scontext=system_u:system_r:init_t:s0 tcontext=system_u:system_r:init_t:s0
> > tclass=service exe="/usr/lib/systemd/systemd" sauid=0 hostname=? addr=?

> > terminal=?' type=VIRT_RESOURCE msg=audit(1395412400.015:284): pid=6856
> > uid=0 auid=4294967295 ses=4294967295
> > subj=system_u:system_r:virtd_t:s0-s0:c0.c1023 msg='virt=qemu resrc=mem

> > reason=start vm="mini" uuid=11111111-2890-2015-1f87-cbfa725b1dd3 old-mem=0
> > new-mem=1048576 exe="/usr/sbin/libvirtd" hostname=? addr=? terminal=?
> > res=success' type=VIRT_RESOURCE msg=audit(1395412400.015:285): pid=6856

> > uid=0 auid=4294967295 ses=4294967295
> > subj=system_u:system_r:virtd_t:s0-s0:c0.c1023 msg='virt=qemu resrc=vcpu
> > reason=start vm="mini" uuid=11111111-2890-2015-1f87-cbfa725b1dd3 old-vcpu=0

> > new-vcpu=1 exe="/usr/sbin/libvirtd" hostname=? addr=? terminal=?
> > res=success' type=VIRT_CONTROL msg=audit(1395412400.015:286): pid=6856
> > uid=0 auid=4294967295 ses=4294967295

> > subj=system_u:system_r:virtd_t:s0-s0:c0.c1023 msg='virt=qemu op=start
> > reason=booted vm="mini" uuid=11111111-2890-2015-1f87-cbfa725b1dd3 vm-pid=-1
> > exe="/usr/sbin/libvirtd" hostname=? addr=? terminal=? res=failed'

> >
> > I'm not overly familiar with SELinux. Is this a configuration issue? Am I
> > missing some policy packages or could this be an issue with the cloud
> > image?
> >
> > Works fine when I disable SELinux.

> >
> > Google found this, but it's old and apparently resolved:
> > https://bugzilla.redhat.com/show_bug.cgi?id=860235
> >

> > Thanks ...Juerg
> >
> >
> >
> > _______________________________________________ cloud mailing list
> > cloud@xxxxxxxxxxxxxxxxxxxxxxx

> > https://admin.fedoraproject.org/mailman/listinfo/cloud Fedora Code of
> > Conduct: http://fedoraproject.org/code-of-conduct

> >
>
> There is no SELinux data that you posted.  I don't think your machine is
> mislabeled.  Doing the /.autorelabel dance is a waste of time.
>
> ausearch -m avc,user_avc -ts recent

>
> After you have the problem, to see if SELinux posted any error messages.
>
> If there are no messages then try to turn off dontaudit rules.
>
> semodule -DB
> Run your test
> ausearch -m avc,user_avc -ts recent

>

This is all I get:

time->Mon Mar 24 10:21:18 2014
type=USER_AVC msg=audit(1395656478.686:22577): pid=1 uid=0 auid=4294967295 ses=4294967295  subj=system_u:system_r:init_t:s0 msg='avc:  denied  { start } for auid=-1 uid=-1 gid=-1 scontext=system_u:system_r:init_t:s0 tcontext=system_u:system_r:init_t:s0 tclass=service  exe="/usr/lib/systemd/systemd" sauid=0 hostname=? addr=? terminal=?'

> And look for messages about virt.
>
> This will turn dontaudit rules back on.
> semodule -B
>
>
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