Re: [PATCH] drm/i915: check before removing mm notifier

[Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>]

On 21/02/2024 11:52, Nirmoy Das wrote:
> Merged it to drm-intel-gt-next with s/check/Check

Shouldn't this have had:

Fixes: ed29c2691188 ("drm/i915: Fix userptr so we do not have to worry about obj->mm.lock, v7.")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.13+

?

Regards,

Tvrtko
 
> On 2/19/2024 1:50 PM, Nirmoy Das wrote:
> > Error in mmu_interval_notifier_insert() can leave a NULL
> > notifier.mm pointer. Catch that and return early.
> >
> > Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
> > Cc: Shawn Lee <shawn.c.lee@xxxxxxxxx>
> > Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
> > ---
> >   drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c 
> > b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> > index 0e21ce9d3e5a..61abfb505766 100644
> > --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> > +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
> > @@ -349,6 +349,9 @@ i915_gem_userptr_release(struct 
> > drm_i915_gem_object *obj)
> >   {
> >       GEM_WARN_ON(obj->userptr.page_ref);
> > +    if (!obj->userptr.notifier.mm)
> > +        return;
> > +
> >       mmu_interval_notifier_remove(&obj->userptr.notifier);
> >       obj->userptr.notifier.mm = NULL;
> >   }