Commit 2e3c18d0 authored Jan 30, 2019 by Tetsuo Handa Committed by Jens Axboe Jan 30, 2019

block: pass no-op callback to INIT_WORK().

syzbot is hitting flush_work() warning caused by commit 4d43d395
("workqueue: Try to catch flush_work() without INIT_WORK().") [1].
Although that commit did not expect INIT_WORK(NULL) case, calling
flush_work() without setting a valid callback should be avoided anyway.
Fix this problem by setting a no-op callback instead of NULL.

[1] https://syzkaller.appspot.com/bug?id=e390366bc48bc82a7c668326e0663be3b91cbd29



Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-and-tested-by: syzbot <syzbot+ba2a929dcf8e704c180e@syzkaller.appspotmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 3ca17a24

block/blk-core.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -462,6 +462,10 @@ static void blk_rq_timed_out_timer(struct timer_list *t)
		kblockd_schedule_work(&q->timeout_work);
		}

		static void blk_timeout_work(struct work_struct *work)
		{
		}

		/**
		* blk_alloc_queue_node - allocate a request queue
		* @gfp_mask: memory allocation flags
		@@ -505,7 +509,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
		timer_setup(&q->backing_dev_info->laptop_mode_wb_timer,
		laptop_mode_timer_fn, 0);
		timer_setup(&q->timeout, blk_rq_timed_out_timer, 0);
		INIT_WORK(&q->timeout_work, NULL);
		INIT_WORK(&q->timeout_work, blk_timeout_work);
		INIT_LIST_HEAD(&q->icq_list);
		#ifdef CONFIG_BLK_CGROUP
		INIT_LIST_HEAD(&q->blkg_list);

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