On Tue, 28 Nov 2017 13:39:58 -0800 Kees Cook <keesc...@chromium.org> wrote:
> On Tue, Nov 28, 2017 at 1:16 PM, Luis R. Rodriguez <mcg...@kernel.org> wrote: > > And *all* auto-loading uses aliases? What's the difference between > > auto-loading > > and direct-loading? > > The difference is the process privileges. Unprivilged autoloading > (e.g. int n_hdlc = N_HDLC; ioctl(fd, > TIOCSETD, &n_hdlc)), triggers a privileged call to finit_module() > under CAP_SYS_MODULE. If you have CAP_SYS_DAC you can rename any module to ppp.ko and ask the network manager (which has the right permissions) to init a ppp connection. Capabilities alone are simply not enough to do any kind of useful protection on a current system and the Linux capability model is broken architecturally and not fixable because fixing it would break lots of real systems. I really don't care what the module loading rules end up with and whether we add CAP_SYS_YET_ANOTHER_MEANINGLESS_FLAG but what is actually needed is to properly incorporate it into securiy ruiles for whatever LSM you are using. Alan
