From: Sean Tranchetti <stran...@codeaurora.org> Date: Fri, 26 Jun 2020 18:31:03 -0600
> @@ -328,6 +325,10 @@ int genl_register_family(struct genl_family *family) > if (err) > return err; > > + /* Acquire netlink table lock before any GENL-specific locks to ensure > + * sync with any netlink operations making calls into the GENL code. > + */ > + netlink_table_grab(); > genl_lock_all(); This locking sequence is illegal, and if you tested this change with the proper lock debugging options enabled you wouldn't have been able to even boot a machine without it OOPS'ing. This code was essentially not tested as far as I am concerned. netlink_table_grab() takes an atomic lock (write_lock_irq), so it creates an atomic section. But then we immediately call genl_lock_all() which takes multiple sleepable locks (a semaphore and a mutex). You'll have to find another way to fix this bug and I would like to ask that you do so in a way that keeps all of these code paths sleepable and does not do any GFP_ATOMIC conversions. Thank you.
