On 10/18/18 9:19 AM, Shuah Khan (Samsung OSG) wrote: > In rmmod path, usbip_vudc does platform_device_put() twice once from > platform_device_unregister() and then from put_vudc_device(). > > The second put results in: > > BUG kmalloc-2048 (Not tainted): Poison overwritten error or > BUG: KASAN: use-after-free in kobject_put+0x1e/0x230 if KASAN is > enabled. > > [ 169.042156] calling init+0x0/0x1000 [usbip_vudc] @ 1697 > [ 169.042396] > ============================================================================= > [ 169.043678] probe of usbip-vudc.0 returned 1 after 350 usecs > [ 169.044508] BUG kmalloc-2048 (Not tainted): Poison overwritten > [ 169.044509] > ----------------------------------------------------------------------------- > ... > [ 169.057849] INFO: Freed in device_release+0x2b/0x80 age=4223 cpu=3 pid=1693 > [ 169.057852] kobject_put+0x86/0x1b0 > [ 169.057853] 0xffffffffc0c30a96 > [ 169.057855] __x64_sys_delete_module+0x157/0x240 > > Fix it to call platform_device_del() instead and let put_vudc_device() do > the platform_device_put(). > > Reported-by: Randy Dunlap <[email protected]> > Signed-off-by: Shuah Khan (Samsung OSG) <[email protected]> > Cc: <[email protected]>
and Tested-by: Randy Dunlap <[email protected]> Thanks. > --- > drivers/usb/usbip/vudc_main.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/usbip/vudc_main.c b/drivers/usb/usbip/vudc_main.c > index 3fc22037a82f..390733e6937e 100644 > --- a/drivers/usb/usbip/vudc_main.c > +++ b/drivers/usb/usbip/vudc_main.c > @@ -73,6 +73,10 @@ static int __init init(void) > cleanup: > list_for_each_entry_safe(udc_dev, udc_dev2, &vudc_devices, dev_entry) { > list_del(&udc_dev->dev_entry); > + /* > + * Just do platform_device_del() here, put_vudc_device() > + * calls the platform_device_put() > + */ > platform_device_del(udc_dev->pdev); > put_vudc_device(udc_dev); > } > @@ -89,7 +93,11 @@ static void __exit cleanup(void) > > list_for_each_entry_safe(udc_dev, udc_dev2, &vudc_devices, dev_entry) { > list_del(&udc_dev->dev_entry); > - platform_device_unregister(udc_dev->pdev); > + /* > + * Just do platform_device_del() here, put_vudc_device() > + * calls the platform_device_put() > + */ > + platform_device_del(udc_dev->pdev); > put_vudc_device(udc_dev); > } > platform_driver_unregister(&vudc_driver); > -- ~Randy
