On 2014-10-30 15:47, Greg Kroah-Hartman wrote: > On Thu, Oct 30, 2014 at 11:44:39AM +0100, Karol Lewandowski wrote: >> [ Sorry for breaking thread and resend - gmane rejected my original message >> due to too long list of recipients... ] >> >> On 2014-10-30 00:40, Greg Kroah-Hartman wrote: >> >>> There is a 1815 line documentation file in this series, so we aren't >>> trying to not provide this type of information here at all. But yes, >>> more background, about why this can't be done in userspace (zero copy, >>> less context switches, proper credential passing, timestamping, availble >>> at early-boot, LSM hooks for security models to tie into >> >> While you're at it... I did some work on proof-of-concept LSM patches for >> kdbus some time ago, see [1][2]. Currently, these are completely of date. >> >> [1] https://github.com/lmctl/linux/commits/kdbus-lsm-v4.for-systemd-v212 >> [2] https://github.com/lmctl/kdbus/commit/aa0885489d19be92fa41c6f0a71df28763228a40 >> >> May I ask if you guys have your own plan for LSM or maybe it would be >> worth to resurrect [1]? > > The core calls are already mediated by LSM today, right? We don't want > anyone to be parsing the data stream through an LSM, that idea got > rejected a long time ago as something that is really not a good idea. Parsing data is out of question, of course, but this is not what we were proposing. > Other than that, I don't know exactly what your patches do, or why they > are needed, care to go into details? Patches in question were supposed to add few hooks for kdbus-specific operations that doesn't seem to have compatible semantics with hooks currently available in LSM. kdbus' bus introduces quite a few new concepts that we wanted to be able to limit based on MAC label/context, eg. - check flags at HELO stage (say disallow fd passing), - restrict ability to acquire name to certain subjects (for system bus), - disallow creation of new buses, - limit scope of broadcasts, - etc. Please take a look at hook list - I think most of names are self-explanatory: https://github.com/lmctl/linux/blob/a9fe4c33b6e5ab25a243e0590df406aabb6add12/include/linux/security.h#L1874 kdbus modifications were pretty light - with most visible change being addition of opaque security pointer to kdbus_bus and similar structs. Thanks! -- Karol Lewandowski, Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
