kmemleak: Check for NULL pointer returned by create_object()

This patch adds NULL pointer checking in the early_alloc() function.
Reported-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NPekka Enberg <penberg@cs.helsinki.fi>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/kmemleak.c

@@ -834,11 +834,14 @@ static void early_alloc(struct early_log *log)
 	rcu_read_lock();
 	object = create_object((unsigned long)log->ptr, log->size,
 			       log->min_count, GFP_ATOMIC);
+	if (!object)
+		goto out;
 	spin_lock_irqsave(&object->lock, flags);
 	for (i = 0; i < log->trace_len; i++)
 		object->trace[i] = log->trace[i];
 	object->trace_len = log->trace_len;
 	spin_unlock_irqrestore(&object->lock, flags);
+out:
 	rcu_read_unlock();
 }