Re: [syzbot] [io-uring?] KASAN: slab-use-after-free Read in io_waitid_wait

[syzbot]

> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git

want either no args or 2 args (repo, branch), got 5

>
> diff --git a/io_uring/waitid.c b/io_uring/waitid.c
> index 26c118f3918d..f25110fb1b12 100644
> --- a/io_uring/waitid.c
> +++ b/io_uring/waitid.c
> @@ -230,13 +230,14 @@ static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode,
>  	if (!pid_child_should_wake(wo, p))
>  		return 0;
>  
> +	list_del_init(&wait->entry);
> +
>  	/* cancel is in progress */
>  	if (atomic_fetch_inc(&iw->refs) & IO_WAITID_REF_MASK)
>  		return 1;
>  
>  	req->io_task_work.func = io_waitid_cb;
>  	io_req_task_work_add(req);
> -	list_del_init(&wait->entry);
>  	return 1;
>  }
>  
>
> -- 
> Jens Axboe