On Fri, May 08, 2009 at 12:43:19PM +0900, Ryota Ozaki wrote:
Hi Serge,
On Fri, May 8, 2009 at 11:04 AM, Serge E. Hallyn <serue@us.ibm.com> wrote:
Quoting Ryota Ozaki (ozaki.ryota@gmail.com):
Hi Serge,
On Fri, May 8, 2009 at 9:12 AM, Serge E. Hallyn <serue@us.ibm.com> wrote:
Quoting Ryota Ozaki (ozaki.ryota@gmail.com):
Hi,
...
+ for (i = 0 ; i < ARRAY_CARDINALITY(caps) ; i++) { + if (prctl(PR_CAPBSET_DROP, caps[i].id, 0, 0, 0)) { + lxcError(NULL, NULL, VIR_ERR_INTERNAL_ERROR, + "%s", _("failed to drop %s"), caps[i].name); + return -1;
Ideally you should also drop it from pI.
If not drop it, a user in a container could set CAP_SYS_BOOT fI bit of /bin/reboot on and then the user could gain CAP_SYS_BOOT back through the fI. Is this understanding right?
Yup.
Of course most tasks run with pI empty, so it seems unlikely that it would be a problem, but unless the libcap dependecy becomes a problem, it seems worth making sure that doesn't happen.
Oh, I slightly misread your suggestions, sorry. You are suggesting making sure requires dropping a capability in both bounding set AND pI of a process and to do so we need an additional package (libcap2 or somewhat) because prctl(2) doesn't have the function to drop pI, aren't you?
um, I hope my patch is sufficient as a first step, but ok, I'll try to implement the function to drop pI as well and confirm whether it is feasible for libvirt.
The patch I have just posted should take care of this issue with pI http://www.redhat.com/archives/libvir-list/2009-June/msg00413.html Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|