Messages in this thread | | | Date | Thu, 16 Mar 2023 11:59:18 -0600 | Subject | Re: [PATCH RESEND] usbip: vudc: Fix use after free bug in vudc_remove due to race condition | From | Shuah Khan <> |
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On 3/16/23 11:48, Zheng Wang wrote: > 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. >
Send me v2 for this patch with adding details on how you found this problem to this commit log.
> 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);
thanks, -- Shuah
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