Commit afa3d8b6 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'rcu/fixes-for-6.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux 

Pull RCU fix from Joel Fernandes:
 "We recently got a report of a crash [1] with misuse of call_rcu().

  Instead of crashing the kernel, a warning and graceful return is
  better:

   - rcu: Return early if callback is not specified (Uladzislau Rezki)"

Link: https://lore.kernel.org/all/aEnVuzK7VhGSizWj@pc636/ [1]

* tag 'rcu/fixes-for-6.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux:
  rcu: Return early if callback is not specified
parents 7c7f9dd1 33b6a1f1

kernel/rcu/tree.c

+4 −0
Original line number Diff line number Diff line
@@ -3072,6 +3072,10 @@ __call_rcu_common(struct rcu_head *head, rcu_callback_t func, bool lazy_in) 
	/* Misaligned rcu_head! */

	WARN_ON_ONCE((unsigned long)head & (sizeof(void *) - 1));



	/* Avoid NULL dereference if callback is NULL. */

	if (WARN_ON_ONCE(!func))

		return;



	if (debug_rcu_head_queue(head)) {

		/*

		 * Probable double call_rcu(), so leak the callback.