On Tue, 7 Mar 2023 at 17:44, Zheng Wang <zyytlz.wz@xxxxxxx> wrote:
>
> In r592_probe, dev->detect_timer was bound with r592_detect_timer.
> In r592_irq function, the timer function will be invoked by mod_timer.
>
> If we remove the module which will call hantro_release to make cleanup,
> there may be a unfinished work. The possible sequence is as follows,
> which will cause a typical UAF bug.
>
> Fix it by canceling the work before cleanup in r592_remove.
>
> CPU0 CPU1
>
> |r592_detect_timer
> r592_remove |
> memstick_free_host|
> put_device; |
> kfree(host); |
> |
> | queue_work
> | &host->media_checker //use
>
> Signed-off-by: Zheng Wang <zyytlz.wz@xxxxxxx>
Applied for next, thanks!
Kind regards
Uffe
> ---
> drivers/memstick/host/r592.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/memstick/host/r592.c b/drivers/memstick/host/r592.c
> index 1d35d147552d..2bfa7eaae80a 100644
> --- a/drivers/memstick/host/r592.c
> +++ b/drivers/memstick/host/r592.c
> @@ -829,7 +829,7 @@ static void r592_remove(struct pci_dev *pdev)
> /* Stop the processing thread.
> That ensures that we won't take any more requests */
> kthread_stop(dev->io_thread);
> -
> + del_timer_sync(&dev->detect_timer);
> r592_enable_device(dev, false);
>
> while (!error && dev->req) {
> --
> 2.25.1
>
