On Thu, Oct 20, 2016 at 7:58 AM, Stephen Smalley <s...@tycho.nsa.gov> wrote: > On 10/20/2016 02:52 AM, Cong Wang wrote: >> A kernel warning inside __local_bh_enable_ip() was reported by people >> running SELinux, this is caused due to some SELinux functions >> (indirectly) call peernet2id() with IRQ disabled in process context, >> when we re-enable BH with IRQ disabled kernel complains. Shut up this >> warning by saving IRQ context in peernet2id(), BH is still implicitly >> disabled. > > Not sure this suffices; kill_fasync() -> send_sigio() -> > send_sigio_to_task() -> sigio_perm() -> security_file_send_sigiotask() > -> selinux_file_send_sigiotask() -> ... -> audit_log() -> ... -> > peernet2id()
Oh, this is a new one. kill_fasync() is called in IRQ handler, so we actually do multicast in IRQ context.... It makes no sense, netlink multicast could be very expensive if we have many listeners. I am Cc'ing Richard who added that multicast in audit_log_end(). It seems not easy to just move the multicast to a workqueue, since the skb is copied from audit_buffer which is freed immediately after that, probably need another queue like audit_skb_queue.
