| Message ID | 20230316180940.1601515-1-zyytlz.wz@163.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] usbip: vudc: Fix use after free bug in vudc_remove due to race condition | expand |
diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c index 2bc428f2e261..33d0991755bb 100644 --- a/drivers/usb/usbip/vudc_dev.c +++ b/drivers/usb/usbip/vudc_dev.c @@ -633,6 +633,7 @@ int vudc_remove(struct platform_device *pdev) { struct vudc *udc = platform_get_drvdata(pdev); + timer_shutdown_sync(&udc->timer); usb_del_gadget_udc(&udc->gadget); cleanup_vudc_hw(udc); kfree(udc);
In vudc_probe, it calls init_vudc_hw, which bound &udc->timer with v_timer. When it calls usbip_sockfd_store, it will call v_start_timer to start the timer work. When we call vudc_remove to remove the driver, theremay be a sequence as follows: Fix it by shutdown the timer work before cleanup in vudc_remove. Note that removing a driver is a root-only operation, and should never happen. CPU0 CPU1 |v_timer vudc_remove | kfree(udc); | //free shost | |udc->gadget |//use This bug was found by static analysis. Fixes: b6a0ca111867 ("usbip: vudc: Add UDC specific ops") Signed-off-by: Zheng Wang <zyytlz.wz@163.com> --- v2: - add more details about how the bug was found suggested by Shuah --- drivers/usb/usbip/vudc_dev.c | 1 + 1 file changed, 1 insertion(+)