[Intel-gfx] [PATCH] drm/i915/gvt: don't dereference 'workload' before null checking it

Chris Wilson chris at chris-wilson.co.uk
Wed Mar 21 19:23:24 UTC 2018

Quoting Colin Ian King (2018-03-21 19:18:28)
> On 21/03/18 19:09, Joe Perches wrote:
> > On Wed, 2018-03-21 at 19:06 +0000, Colin King wrote:
> >> From: Colin Ian King <colin.king at canonical.com>
> >>
> >> The pointer workload is dereferenced before it is null checked, hence
> >> there is a potential for a null pointer dereference on workload. Fix
> >> this by only dereferencing workload after it is null checked.
> >>
> >> Detected by CoverityScan, CID#1466017 ("Dereference before null check")
> > 
> > Maybe true, but is it possible for workload to be null?
> > Maybe the null test should be removed instead.
> From what I understand from the static analysis, there may be a
> potential for workload to be null, I couldn't rule it out so I went with
> the more paranoid stance of keeping the null check in.

Not sr_oa_regs() problem if workload is NULL, that's the callers. I
reviewed the identical patch yesterday, and we ended up with removing
the NULL checks, just keeping the workload->id != RCS.

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