← Back to team overview

group.of.nepali.translators team mailing list archive

[Bug 1546674] Re: virt-aa-helper Apparmor profile missing rules for name resolution

 

Not much that we can do about the conffile prompt indeed. However, I
disagree with the actual patch. This should include
abstractions/nameservice instead, which allows these files plus a lot
more for other name service methods. We really want to avoid having to
SRU a conffile change twice, and this is *definitively* not sufficient
for 16.10 and up (as you e. g. also need to be able to talk to
resolved). Please also fix this in zesty. Thanks!

** Changed in: libvirt (Ubuntu)
       Status: Fix Released => In Progress

-- 
You received this bug notification because you are a member of नेपाली
भाषा समायोजकहरुको समूह, which is subscribed to Xenial.
Matching subscriptions: Ubuntu 16.04 Bugs
https://bugs.launchpad.net/bugs/1546674

Title:
  virt-aa-helper Apparmor profile missing rules for name resolution

Status in libvirt package in Ubuntu:
  In Progress
Status in libvirt source package in Xenial:
  Triaged

Bug description:
  [Impact]

   * Apparmor denies several hostname related accesses by libvirt causing 
     severe slowdowns in some cases.

  [Test Case]

  * Note: while there are various ways to trigger it - many have seen the 
    issue, but often it is unclear when exactly it will trigger or does no 
    more. So some of the repo-cases have proven to be unreliable - thanks 
    Simon for this Repro howto listed here. (simplified as it turned out 
    zvols are not needed according to comment #22)

  1) Sync Xenial cloud-image
  uvt-simplestreams-libvirt sync --source http://cloud-images.ubuntu.com/daily arch=amd64 label=daily release=xenial

  2) Create a test guest with:
  uvt-kvm create --memory 2048 --cpu 4 --password=ubuntu xenial-kernel-test release=xenial arch=amd64 label=daily

  3) strop it and add an extra volume in a way like this snippet
     $ virsh shutdown xenial-kernel-test
     $ virsh edit xenial-kernel-test
      <disk type='file' device='disk'>
        <driver name='qemu' type='raw' cache='none'/>
        <source file='/dev/sda4'/>
        <target dev='vdc' bus='virtio'/>
      </disk>

  4) start the guest
  virsh start xenial-kernel-test

  6) check for apparmor denial messages
  dmesg | tail | grep apparmor

  Without the fix, Apparmor would report denials when accessing
  /etc/nsswitch.conf, /etc/host.conf, /etc/gai.conf,
  /run/resolvconf/resolv.conf and /dev/zdX (where X corresponds to the
  zvol number). Starting the guest should be much slower than usual.

  With the fix in place no related Apparmor denials show up.

  [Regression Potential]

   * The fix is rather small and "only" opens up apparmor confinement a bit. 
     That makes us assume that the potential for regression should be 
     minimal.

  ###############

  Original description:

  With libvirt-bin 1.3.1, starting a QEMU guest results in those AA
  denials:

  Feb 17 12:06:23 simon-laptop kernel: [15734.513696] audit: type=1400 audit(1455728783.639:73): apparmor="DENIED" operation="open" profile="/usr/lib/libvirt/virt-aa-helper" name="/etc/nsswitch.conf" pid=23156 comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
  Feb 17 12:06:23 simon-laptop kernel: [15734.513718] audit: type=1400 audit(1455728783.639:74): apparmor="DENIED" operation="open" profile="/usr/lib/libvirt/virt-aa-helper" name="/etc/host.conf" pid=23156 comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
  Feb 17 12:06:23 simon-laptop kernel: [15734.513734] audit: type=1400 audit(1455728783.639:75): apparmor="DENIED" operation="open" profile="/usr/lib/libvirt/virt-aa-helper" name="/run/resolvconf/resolv.conf" pid=23156 comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
  Feb 17 12:06:23 simon-laptop kernel: [15734.513885] audit: type=1400 audit(1455728783.639:76): apparmor="DENIED" operation="open" profile="/usr/lib/libvirt/virt-aa-helper" name="/run/resolvconf/resolv.conf" pid=23156 comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0

  virt-aa-helper's AA profile hasn't changed recently so it seems like
  the helper is doing more in this release.

  Additional information:

  $ lsb_release -rd
  Description:	Ubuntu Xenial Xerus (development branch)
  Release:	16.04

  $ apt-cache policy apparmor libvirt-bin
  apparmor:
    Installed: 2.10-3ubuntu1
    Candidate: 2.10-3ubuntu1
    Version table:
   *** 2.10-3ubuntu1 500
          500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages
          100 /var/lib/dpkg/status
  libvirt-bin:
    Installed: 1.3.1-1ubuntu1
    Candidate: 1.3.1-1ubuntu1
    Version table:
   *** 1.3.1-1ubuntu1 500
          500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages
          100 /var/lib/dpkg/status

  ProblemType: Bug
  DistroRelease: Ubuntu 16.04
  Package: libvirt-bin 1.3.1-1ubuntu1
  ProcVersionSignature: Ubuntu 4.4.0-5.20-generic 4.4.1
  Uname: Linux 4.4.0-5-generic x86_64
  NonfreeKernelModules: zfs zunicode zcommon znvpair zavl
  ApportVersion: 2.20-0ubuntu3
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Wed Feb 17 13:08:04 2016
  KernLog:

  SourcePackage: libvirt
  UpgradeStatus: No upgrade log present (probably fresh install)
  modified.conffile..etc.libvirt.qemu.conf: [inaccessible: [Errno 13] Permission denied: '/etc/libvirt/qemu.conf']
  modified.conffile..etc.libvirt.qemu.networks.default.xml: [deleted]

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1546674/+subscriptions