[Intel-gfx] [PATCH] drm/i915: Fix null pointer dereference in ring cleanup code

[Chris Wilson]

On Fri, Oct 31, 2014 at 02:52:40PM +0000, Damien Lespiau wrote:
> On Fri, Oct 31, 2014 at 12:00:26PM +0000, John.C.Harrison at Intel.com wrote:
> > From: John Harrison <John.C.Harrison at Intel.com>
> > 
> > If a ring failed to initialise for any reason then the error path would try to
> > clean up all rings including those that had not yet been allocated. The ring
> > clean up code did a check that the ring was valid before starting its work.
> > Unfortunately, that was after it had already dereferenced the ring to obtain a
> > dev_private pointer.
> > 
> > Signed-off-by: John Harrison <John.C.Harrison at Intel.com>
> 
> This looks good to me.

Really? These functions(!!!) are only called under controlled conditions...
I would have been happy to see this follow my suggestion I made to fix
this bug months ago.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre