On 10/15/2012 03:03 AM, Guannan Ren wrote:
BZ:https://bugzilla.redhat.com/show_bug.cgi?id=851981 When using macvtap, a character device gets first created by kernel with name /dev/tapN, its selinux context is: system_u:object_r:device_t:s0
Shortly, when udev gets notification when new file is created in /dev, it will then jump in and relabel this file back to the expected default context: system_u:object_r:tun_tap_device_t:s0
There is a time gap happened. Sometimes, it will have migration failed, AVC error message: type=AVC msg=audit(1349858424.233:42507): avc: denied { read write } for pid=19926 comm="qemu-kvm" path="/dev/tap33" dev=devtmpfs ino=131524 scontext=unconfined_u:system_r:svirt_t:s0:c598,c908 tcontext=system_u:object_r:device_t:s0 tclass=chr_file
This patch will label the tapfd device before qemu process starts: system_u:object_r:tun_tap_device_t:MCS(MCS from seclabel->label) ---
This patch is breaking things for me - with it applied, I'm now seeing /dev/net/tun with a label of :MCS that matches the most recently started guest, which prevents other tun clients (like openvpn) from creating their own tapfd. I haven't yet looked closely to see where in this patch you are labeling the wrong file, but it needs to be fixed. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org