[libvirt] Implementation deficiency in virInitctlSetRunLevel

Hello, list. I was pointed here by maintainer of libvirt package in Debian, Guido Günther. For the sake of completeness, the original bug report can be viewed at this link: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=732394 To sum up the bug report, current implementation of virInitctlSetRunLevel function (src/util/virinitctl.c) lacks any sanity checks before writing to container's /dev/initctl. In the absence of such checks, libvirtd can be easily tricked to write runlevel check request to an arbitrary main hosts' file (including hosts' /run/initctl, as described in the bug report). All it takes is one symlink in place of containers' /dev/initctl. I've checked current libvirtd's git, and it seems to me that the problem is still here. Attached to this letter is a patch which tries to mitigate the issue by checking whenever container's /dev/initctl is a pipe actually. Sincerely yours, Reco PS I'm not subscribed to this list, in case of further questions please CC me.