On Thu, Nov 17, 2022 at 05:10:07PM -0500, Paul Moore wrote: > On Thu, Nov 17, 2022 at 4:40 AM Joel Granados <j.granados@xxxxxxxxxxx> wrote: > > On Wed, Nov 16, 2022 at 02:21:14PM -0500, Paul Moore wrote: > > ... > > > > * As we discussed previously, the real problem is the fact that we are > > > missing the necessary context in the LSM hook to separate the > > > different types of command targets. With traditional ioctls we can > > > look at the ioctl number and determine both the type of > > > device/subsystem/etc. as well as the operation being requested; there > > > is no such information available with the io_uring command > > > passthrough. In this sense, the io_uring command passthrough is > > > actually worse than traditional ioctls from an access control > > > perspective. Until we have an easy(ish)[1] way to determine the > > > io_uring command target type, changes like the one suggested here are > > > going to be doomed as each target type is free to define their own > > > io_uring commands. > > > > The only thing that comes immediately to mind is that we can have > > io_uring users define a function that is then passed to the LSM > > infrastructure. This function will have all the logic to give relative > > context to LSM. It would be general enough to fit all the possible commands > > and the logic would be implemented in the "drivers" side so there is no > > need for LSM folks to know all io_uring users. > > Passing a function pointer to the LSM to fetch, what will likely be > just a constant value, seems kinda ugly, but I guess we only have ugly > options at this point. I am not sure if this helps yet, but queued on modules-next we now have an improvement in speed of about 1500x for kallsyms_lookup_name(), and so symbol lookups are now fast. Makes me wonder if a type of special export could be drawn up for specific calls which follow a structure and so the respective lsm could be inferred by a prefix instead of placing the calls in-place. Then it would not mattter where a call is used, so long as it would follow a specific pattern / structure with all the crap you need on it. Luis
