Commit 5e351ad1 authored Dec 06, 2017 by Peter Zijlstra Committed by Ingo Molnar Dec 06, 2017

locking/lockdep: Fix possible NULL deref



We can't invalidate xhlocks when we've not yet allocated any.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: f52be570 ("locking/lockdep: Untangle xhlock history save/restore from task independence")
Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 328b4ed9

kernel/locking/lockdep.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -4790,6 +4790,7 @@ void lockdep_invariant_state(bool force)
		* Verify the former, enforce the latter.
		*/
		WARN_ON_ONCE(!force && current->lockdep_depth);
		if (current->xhlocks)
		invalidate_xhlock(&xhlock(current->xhlock_idx));
		}