[Jaunty] SRU: Fix radio-maestro probe failures causing a kernel oops

[Tim Gardner]

Colin Ian King wrote:
> SRU Justification:
> 
> Impact: A failed radio-maestro probe always generates a kernel oops.
> 
> Probe failures in maestro_probe cause a double call to
> video_device_release():
> 
>  a) indirectly when calling video_unregister_device()
> via dev->release(dev) in device_release()
>  b) explicity in the error handling at label errfr1
> 
> The second call causes the oops. This bug was introduced
> with commit aa5e90af7d78d1711f8f4275ce3638817c0023dc when the
> release method was added to struct video_device maestro_radio
> but the error handling was not updated to take this into
> consideration.
> 
> The fix: Correct the error handling path to avoid the
> double release.
> 
> Test case: Without this fix, the kernel generates an oops when a probe
> fails. With the fix, there is no oops.  Tested by user GertjanVD.
> 
> 
> 

ACK

-- 
Tim Gardner tim.gardner at canonical.com