Created attachment 516007 [details]
Patch to fix the problem
Description of problem:
After doing some testing, I found that dbus needs to drop supplemental groups when switching uids.
Version-Release number of selected component (if applicable):
cat /proc/<pid>/status | grep Groups
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
Can you give me a link for WHY this is useful? That would help me to put it in the upstream git.
The bottom line is this: not dropping supplemental groups allows processes to retain some group privileges. When started by init, dbus does not have these. However, if an admin does an update and restarts dbus, then it will inherit the supplemental groups from the admin's login. On RHEL, root and disk and a few others are retained.
So, if there is another bug in dbus, then the CVE will have to assess the CVSS impact differently because of these elevated permissions. So, a modify user's homedir bug becomes complete system compromise bug. I filed bugs on several other daemons, so this is not unique to dbus.
Ok, so this will be irrelevant for RHEL 7 where systemd fixes that long standing Unix misfeature of admin shell settings propagating into init scripts and then into daemons.
Still worth fixing before then though. I'll push it upstream now.
(Note I had to write a commit message for you; please submit 'git format-patch' patches against upstream for future changes)
So for RHEL...does security team want this out combined with the next update? Or how do you want it in?
Red Hat Enterprise Linux 6 is in the Production 3 Phase. During the Production 3 Phase, Critical impact Security Advisories (RHSAs) and selected Urgent Priority Bug Fix Advisories (RHBAs) may be released as they become available.
The official life cycle policy can be reviewed here:
This issue does not meet the inclusion criteria for the Production 3 Phase and will be marked as CLOSED/WONTFIX. If this remains a critical requirement, please contact Red Hat Customer Support to request a re-evaluation of the issue, citing a clear business justification. Note that a strong business justification will be required for re-evaluation. Red Hat Customer Support can be contacted via the Red Hat Customer Portal at the following URL: