From mboxrd@z Thu Jan 1 00:00:00 1970 From: peter.moody@gmail.com (Peter Moody) Date: Tue, 21 Mar 2017 09:06:53 -0700 Subject: out of tree lsm's In-Reply-To: <04d6fd0a-bb59-b3c0-258c-b5826e7277a0@schaufler-ca.com> References: <201703210718.CJE73456.MVHOFFQFLSJOOt@I-love.SAKURA.ne.jp> <201703211941.CBC26593.FtOLFQFJSOMOHV@I-love.SAKURA.ne.jp> <04d6fd0a-bb59-b3c0-258c-b5826e7277a0@schaufler-ca.com> Message-ID: To: linux-security-module@vger.kernel.org List-Id: linux-security-module.vger.kernel.org On Tue, Mar 21, 2017 at 8:36 AM, Casey Schaufler wrote: > On 3/21/2017 3:41 AM, Tetsuo Handa wrote: >> Tetsuo Handa wrote: >>> Casey Schaufler wrote: >>>>> right. sorry for the imprecise language; by site-specific I meant a "small" lsm. >>>>> >>>>> I would love to have the ability write a small lsm that I can build as >>>>> a module and load at boot eg. via initrd. >>>>> >>>>> AIUI, adding even a new "small" lsm requires kconfig patches, building >>>>> a new kernel, etc. I know there are objections to dynamically loadable >>>>> lsms and I was trying to find a compromise that made them easier to >>>>> work with. >>>> The stacking design criteria I'm working with >>>> include not doing anything that would prevent >>>> dynamic module loading. I do not plan to implement >>>> dynamic loading. Tetsuo has been a strong >>>> advocate of loadable modules. I would expect to >>>> see a proposal from him shortly after the >>>> general stacking lands, assuming it does. >>> But currently __lsm_ro_after_init which is planned to go to 4.12 is preventing >>> dynamic modules from loading. We need a legitimate interface for loadable modules like >>> http://lkml.kernel.org/r/201702152342.GBH04183.FOFJFHQOLMOtVS at I-love.SAKURA.ne.jp . >>> Requiring rodata=0 kernel command line option to allow dynamic modules is silly. >>> >> I think we need something like below change when allowing loadable modules. > > I believe that a simpler approach would be to > add a separate list of dynamic hooks to supliment > the list of static hooks. If SELinux unloading is > desired the SELinux hooks would be put on the > dynamic list which would not be "hardened" with > _ro_after_init, where the rest of the static modules > would be. FWIW, I don't know if that would solve the case I was initially asking about since the out-of-tree lsm I was hoping to be able to access all of the standard security hooks with an out-of-tree module. -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html