** Description changed: - Reproducing steps: + [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) Create a zvol - zfs create -V 8G zlxd/xenial-kernel-test + 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) Copy the qcow2 data to the zvol - qemu-img convert -O raw \ - /var/lib/uvtool/libvirt/images/xenial-kernel-test.qcow \ - /dev/zvol/zlxd/xenial-kernel-test - - 5) Update the guest definition to use the zvol - <disk type='file' device='disk'> - <driver name='qemu' type='raw' cache='none'/> - <source file='/dev/zvol/zlxd/xenial-kernel-test'/> - <target dev='vda' bus='virtio'/> - </disk> - - 6) boot the guest + 4) start the guest virsh start xenial-kernel-test - 7) check for apparmor denial messages + 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, the only Apparmor denial would be about reading - the /dev/zdx device (see LP: #1641618). This causes no visible problem - nor slowdown. + 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]
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1546674 Title: virt-aa-helper Apparmor profile missing rules for name resolution To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1546674/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
