Messages in this thread | | | From | Andy Lutomirski <> | Date | Mon, 31 Aug 2015 12:09:53 -0700 | Subject | Re: kdbus_proc_permission (Re: [GIT PULL] kdbus updates for Greg) |
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On Mon, Aug 31, 2015 at 9:22 AM, David Herrmann <dh.herrmann@gmail.com> wrote: > Hi > > On Mon, Aug 31, 2015 at 5:37 PM, Andy Lutomirski <luto@amacapital.net> wrote: >> On Mon, Aug 24, 2015 at 2:52 AM, David Herrmann <dh.herrmann@gmail.com> wrote: >>> On Mon, Aug 10, 2015 at 4:42 AM, Andy Lutomirski <luto@amacapital.net> wrote: >>>> I haven't checked the context in which it's used, but in order for >>>> kdbus_proc_permission to do what it claims to do, it appears to be >>>> missing calls to security_inode_permission and >>>> security_file_permission. >>> >>> Both are expected to be added by lsm patches (both hooks you mentioned >>> are empty if no lsm is selected). >> >> Will that mean that existing MAC policies stop being fully enforced >> (in effect) if kdbus is installed? > > It means kdbus messages carry information about the sender, which LSMs > might prevent you to read via /proc. Just like you can send dbus > messages to a peer, which LSM-enhanced dbus-daemon might not allow.
It's a security-sensitive function that doesn't do what the name and description suggest. Whether that's an active problem or not is unknown, but it's certainly a maintainability problem.
> If > you use LSMs, we clearly advise you to wait for kdbus to gain LSM > support. We explicitly support legacy dbus1-compat for exactly such > reasons.
This is not an acceptable attitude for security.
There are so many things wrong with your statement that I'll limit myself to one of them: Fedora 23/Rawhide, which is the *reference* platform, uses SELinux.
--Andy
> > Thanks > David
-- Andy Lutomirski AMA Capital Management, LLC
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