[libvirt] PATCH 3/4: AppArmor updates

[Daniel P. Berrange]

On Thu, Sep 23, 2010 at 11:49:21AM -0500, Jamie Strandboge wrote:
> On Thu, 2010-09-23 at 16:10 +0100, Daniel P. Berrange wrote:
> > On Mon, Aug 16, 2010 at 02:45:02PM -0500, Jamie Strandboge wrote:
> > > Author: Jamie Strandboge <jamie at canonical.com>
> > > Description: AppArmor example profile adjustments:
> > >  - libvirt-qemu: allow guests setgid and setuid so qemu can drop privileges
> > >  - virt-aa-helper:
> > >    + allow access to @{PROC}/[0-9]*/net/psched
> > >    + allow searching /sys/bus/usb/devices/
> > >    + deny access to /dev to suppress confusing, non-fatal profile denials
> > >    + allow access to user-tmp abstraction
> > > Bug-Ubuntu: LP: #579584, LP: #565691
> > > 
> > > diff -Naurp libvirt.orig/examples/apparmor/libvirt-qemu libvirt/examples/apparmor/libvirt-qemu
> > > --- libvirt.orig/examples/apparmor/libvirt-qemu	2010-04-06 16:14:52.000000000 -0500
> > > +++ libvirt/examples/apparmor/libvirt-qemu	2010-08-13 16:46:34.000000000 -0500
> > > @@ -1,4 +1,4 @@
> > > -# Last Modified: Mon Apr  5 15:11:27 2010
> > > +# Last Modified: Fri Aug 13 16:38:32 2010
> > >  
> > >    #include <abstractions/base>
> > >    #include <abstractions/consoles>
> > > @@ -9,6 +9,10 @@
> > >    capability dac_read_search,
> > >    capability chown,
> > >  
> > > +  # needed to drop privileges
> > > +  capability setgid,
> > > +  capability setuid,
> > > +
> > >    network inet stream,
> > >    network inet6 stream,
> > 
> > Does QEMU really need this ? The libvirt QEMU driver will drop
> > privileges from root:root to qemu:qemu after forking, but before
> > the /usr/bin/qemu binary is actually exec'd. 
> 
> Yes. Users were seeing errors like:
> libvir: QEMU error : cannot change to '109' group: Operation not
> permitted
> libvir: QEMU error : cannot change to '104' user: Operation not
> permitted

Hmm, that's a libvirt error rather than a QEMU error. Is the restricted
AppArmour policy taking effect *before* the actual QEMU binary is exec()d ?


Daniel
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