On Thu, 2022-02-17 at 15:59 -0500, Stefan Berger wrote: > > > >> Move the ima_lsm_policy_notifier into the ima_namespace. Each IMA > >> namespace can now register its own LSM policy change notifier callback. > >> The policy change notifier for the init_ima_ns still remains in init_ima() > >> and therefore handle the registration of the callback for all other > >> namespaces in init_ima_namespace(). > >> > >> Suppress the kernel warning 'rule for LSM <label> is undefined` for all > >> other IMA namespaces than the init_ima_ns. > > Instead of ignoring the warnings totally, perhaps use either the > > "ratelimited" or "once" function options for non init_ima_ns. It would > > be nice if these functions could be namespace aware, so that each > > affected IMA namespace would contain at least one warning. > > The problem is that any user can now repeatedly create user namespaces > and with that IMA namespaces and cause the kernel log to fill up with > these messages and also flood the audit log -- I guess one could > describe it as an unwanted side-effect. I am afraid that for as long as > the kernel log is not namespaced it's probably best to just turn them > off for non-init_ima_ns. There are functions - pr_warn_once() or pr_warn_ratelimited() - that limit the number of kernel messages. In addition to the number of potential kernel messages, there's also the issue of being able to differentiate between init_ima_ns and other IMA namespaces. I think that is more of a concern than rate limiting. -- thanks, Mimi
