Messages in this thread Patch in this message | | | From | Zheng Wang <> | Subject | [PATCH RESEND] usbip: vudc: Fix use after free bug in vudc_remove due to race condition | Date | Fri, 17 Mar 2023 01:48:18 +0800 |
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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
Fixes: b6a0ca111867 ("usbip: vudc: Add UDC specific ops") Signed-off-by: Zheng Wang <zyytlz.wz@163.com> --- drivers/usb/usbip/vudc_dev.c | 1 + 1 file changed, 1 insertion(+)
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); -- 2.25.1
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