On Tue, 31 Jan 2017, Guenter Roeck wrote: > When unloading the r8152 driver using the 'unbind' sysfs attribute > in a system with KASAN enabled, the following error message is seen > on a regular basis. ... > The two-byte allocation in conjunction with code analysis suggests that > the interrupt buffer has been overwritten. Added instrumentation in the > driver shows that the interrupt handler is called after RTL8152_UNPLUG > was set, and that this event is associated with the error message above. > This suggests that there are situations where the interrupt buffer is used > after it has been freed. > > To avoid the problem, allocate the interrupt buffer as part of struct > r8152. > > Cc: Hayes Wang <hayeswang@xxxxxxxxxxx> > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> > --- > The problem is seen in chromeos-4.4, but there is not reason to believe > that it does not occur with the upstream kernel. It is still seen in > chromeos-4.4 after all patches from upstream and linux-next have been > applied to the driver. > > While relatively simple, I am not really convinced that this is the best > (or even an acceptable) solution for this problem. I am open to suggestions > for a better fix. The proper approach is to keep the allocation as it is, but _before_ deallocating the buffer, make sure that the interrupt buffer won't be accessed any more. This may involve calling usb_kill_urb(), or synchronize_irq(), or something similar. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
