Messages in this thread | | | Date | Mon, 3 Oct 2011 12:37:57 -0400 | From | Konrad Rzeszutek Wilk <> | Subject | Re: [Xen-devel] [PATCH 9/9] xen/p2m/debugfs: Fix potential pointer exception. |
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On Fri, Sep 30, 2011 at 09:18:17AM +0100, Ian Campbell wrote: > On Thu, 2011-09-29 at 20:52 +0100, Konrad Rzeszutek Wilk wrote: > > We could be referencing the last + 1 element of level_name[] > > array which would cause a pointer exception. > > If we end up accessing it does that not mean something, i.e. should it > not be a real string here and not NULL? Otherwise isn't it a bug in the > lookup code that we end up looking there?
Yup. I altereted it per your recommendation to be "error".
> > I think this lookup correspond to the initialisation of lvl=4 and > falling through the subsequent list of checks without matching one. In > which case I think level_name[4] should be "unknown" or even "error".
Picked "error" > > I don't think you can hit type_name[4] in the same way, type and > prev_type are always one of the TYPE_* defines, which have values 0..3 > inclusive. You could make this more obvious and defend against future > changes breaking this with: > ... type_name[] = { > [TYPE_IDENTITY] = "identity", > [TYPE_MISSING] = "missing" > ... > };
Oooh, pretty. OK, queued another patch with that.
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