| Message ID | 20240513021948.133039-1-congei42@163.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1] usb: cdns3: cdns3-gadget: fix use-after-free bug in cdns3_gadget_exit due to race | expand |
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index fd1beb10bba7..0f2e143bd17a 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -3252,6 +3252,9 @@ static void cdns3_gadget_exit(struct cdns *cdns) pm_runtime_mark_last_busy(cdns->dev); pm_runtime_put_autosuspend(cdns->dev); + cancel_work_sync(&priv_dev->pending_status_wq); + cancel_work_sync(&priv_dev->aligned_buf_wq); + usb_del_gadget(&priv_dev->gadget); devm_free_irq(cdns->dev, cdns->dev_irq, priv_dev);
This bug exists in drivers/usb/cdns3/cdns3-gadget.c. Function __cdns3_gadget_init will call cdns3_gadget_start to do futher jobs during the initialization proccess of cdns3 gadget. In cdns3_gadget_start, &priv_dev->pending_status_wq is bound with cdns3_pending_setup_status_handler. Then this work will be added to system_freezable_wq in cdns3_gadget_ep0_queue. Here is the code. queue_work(system_freezable_wq, &priv_dev->pending_status_wq); If we call cdns3_gadget_exit to remove the device and make cleanup, there are some unfinished works. This function will call cdns3_free_all_eps to free all the endpoints. However, if cdns3_pending_setup_status_handler is scheduled to run after the free job, it will cause use-after-free error as cdns3_pending_setup_status_handler will use the endpoint in the following code. request->complete(&priv_dev->eps[0]->endpoint, request); The possible execution flow that may lead to this issue is as follows: CPU0 CPU1 | __cdns3_gadget_init | cdns3_gadget_start cdns3_gadget_exit | cdns3_free_all_eps | devm_kfree (free) | | cdns3_pending_setup_status_handler | &priv_dev->eps[0]->endpoint (use) Fix it by cleaning the work in cdns3_gadget_exit. Signed-off-by: Sicong Huang <congei42@163.com> --- drivers/usb/cdns3/cdns3-gadget.c | 3 +++ 1 file changed, 3 insertions(+)