Re: [libvirt] [PATCH 01/10] virt-aa-helper: Ask for no deny rule for readonly disk elements
On Fri, May 19, 2017 at 11:18:18AM +0200, Christian Ehrhardt wrote:
On Fri, May 19, 2017 at 10:03 AM, Guido Günther
<agx(a)sigxcpu.org> wrote:
> But if we aim for a profile replace on blockcommit [1] the would't matter
> since the whole profile would get replaced, wouldn't it?
>
Since this is based on [1][2] looping in Cédric here to share some old
explaiantions.
See especially [1] for some reasoning for 'R' in general.
[1]:
http://libvirt.org/git/?p=libvirt.git;a=commit;h=c726af2d5a2248f0dad01201...
[2]:
http://libvirt.org/git/?p=libvirt.git;a=commit;h=cedd2ab28262db62976b351d...
Let me try to explain why I don't consider this to be a proper fix:
virsh blockcommit is invoked this leads to:
1.) qemuDomainBlockCommit ->
2.) qemuDomainDiskChainElementPrepare ->
3.) qemuSecuritySetImageLabel ->
4.) AppArmorSetSecurityImageLabel (triggers profile reload only) ->
5.) virt-aa-helper does the profile reload ->
6.) failure since the image has an explicit deny rule
The path in question tries to fix this at 5.) by not adding a deny write
rule at all but the place to fix this is 4.) since
AppArmorSetSecurityImageLabel does not take the virStorageSourcePtr src
element into account to create a virDomainDefPtr based on def that marks
the image in question as 'rw' but "only" reloads the profile.
Cheers,
-- Guido