Commit 214c783d authored by Walter Wu's avatar Walter Wu Committed by Linus Torvalds
Browse files

lib/test_kasan.c: add workqueue test case 

Adds a test to verify workqueue stack recording and print it in
KASAN report.

The KASAN report was as follows(cleaned up slightly):

 BUG: KASAN: use-after-free in kasan_workqueue_uaf

 Freed by task 54:
  kasan_save_stack+0x24/0x50
  kasan_set_track+0x24/0x38
  kasan_set_free_info+0x20/0x40
  __kasan_slab_free+0x10c/0x170
  kasan_slab_free+0x10/0x18
  kfree+0x98/0x270
  kasan_workqueue_work+0xc/0x18

 Last potentially related work creation:
  kasan_save_stack+0x24/0x50
  kasan_record_wq_stack+0xa8/0xb8
  insert_work+0x48/0x288
  __queue_work+0x3e8/0xc40
  queue_work_on+0xf4/0x118
  kasan_workqueue_uaf+0xfc/0x190

Link: https://lkml.kernel.org/r/20201203022748.30681-1-walter-zh.wu@mediatek.com


Signed-off-by: default avatarWalter Wu <walter-zh.wu@mediatek.com>
Acked-by: default avatarMarco Elver <elver@google.com>
Reviewed-by: default avatarDmitry Vyukov <dvyukov@google.com>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ef133461

lib/test_kasan_module.c

+29 −0
Original line number Diff line number Diff line
@@ -91,6 +91,34 @@ static noinline void __init kasan_rcu_uaf(void) 
	call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim);

}



static noinline void __init kasan_workqueue_work(struct work_struct *work)

{

	kfree(work);

}



static noinline void __init kasan_workqueue_uaf(void)

{

	struct workqueue_struct *workqueue;

	struct work_struct *work;



	workqueue = create_workqueue("kasan_wq_test");

	if (!workqueue) {

		pr_err("Allocation failed\n");

		return;

	}

	work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);

	if (!work) {

		pr_err("Allocation failed\n");

		return;

	}



	INIT_WORK(work, kasan_workqueue_work);

	queue_work(workqueue, work);

	destroy_workqueue(workqueue);



	pr_info("use-after-free on workqueue\n");

	((volatile struct work_struct *)work)->data;

}



static int __init test_kasan_module_init(void)

{
@@ -102,6 +130,7 @@ static int __init test_kasan_module_init(void) 


	copy_user_test();

	kasan_rcu_uaf();

	kasan_workqueue_uaf();



	kasan_restore_multi_shot(multishot);

	return -EAGAIN;