io_uring: fix a use after free in io_async_task_func()

The "apoll" variable is freed and then used on the next line.  We need
to move the free down a few lines.

Fixes: 0be0b0e33b ("io_uring: simplify io_async_task_func()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Dan Carpenter 2020-07-08 21:47:11 +03:00 committed by Jens Axboe
parent b2edc0a77f
commit aa340845ae

View File

@ -4655,12 +4655,13 @@ static void io_async_task_func(struct callback_head *cb)
/* restore ->work in case we need to retry again */
if (req->flags & REQ_F_WORK_INITIALIZED)
memcpy(&req->work, &apoll->work, sizeof(req->work));
kfree(apoll);
if (!READ_ONCE(apoll->poll.canceled))
__io_req_task_submit(req);
else
__io_req_task_cancel(req, -ECANCELED);
kfree(apoll);
}
static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,