Re: kdbus_proc_permission (Re: [GIT PULL] kdbus updates for Greg)
From: Josh Boyer
Date: Tue Sep 01 2015 - 13:13:32 EST
On Mon, Aug 31, 2015 at 3:09 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
> On Mon, Aug 31, 2015 at 9:22 AM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote:
>> On Mon, Aug 31, 2015 at 5:37 PM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>>> On Mon, Aug 24, 2015 at 2:52 AM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote:
>>>> On Mon, Aug 10, 2015 at 4:42 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> 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
>>>> 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.
>> you use LSMs, we clearly advise you to wait for kdbus to gain LSM
>> support. We explicitly support legacy dbus1-compat for exactly such
> 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.
Clarification: Fedora Rawhide only. The kdbus code is not included in
the F23 kernel.
Your point otherwise stands. I just don't want Phoronix or someone
else getting confused and thinking Fedora 23 will ship with kdbus. It
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