Commit 0a5b4128 authored by Sami Tolvanen's avatar Sami Tolvanen Committed by Kees Cook
Browse files

kthread: use WARN_ON_FUNCTION_MISMATCH 



With CONFIG_CFI_CLANG, a callback function passed to
__kthread_queue_delayed_work from a module points to a jump table
entry defined in the module instead of the one used in the core
kernel, which breaks function address equality in this check:

  WARN_ON_ONCE(timer->function != ktead_delayed_work_timer_fn);

Use WARN_ON_FUNCTION_MISMATCH() instead to disable the warning
when CFI and modules are both enabled.

Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Tested-by: default avatarNathan Chancellor <nathan@kernel.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-7-samitolvanen@google.com
parent 98173112

kernel/kthread.c

+2 −1
Original line number Diff line number Diff line
@@ -963,7 +963,8 @@ static void __kthread_queue_delayed_work(struct kthread_worker *worker, 
	struct timer_list *timer = &dwork->timer;

	struct kthread_work *work = &dwork->work;



	WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn);

	WARN_ON_FUNCTION_MISMATCH(timer->function,

				  kthread_delayed_work_timer_fn);



	/*

	 * If @delay is 0, queue @dwork->work immediately.  This is for