Commit 214c783d authored Dec 14, 2020 by Walter Wu Committed by Linus Torvalds Dec 15, 2020

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: Walter Wu <walter-zh.wu@mediatek.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Andrey 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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;

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