[PATCH 3/4] drm/panthor: Reset the FW VM to NULL on unplug

[Liviu Dudau]

On Fri, May 03, 2024 at 10:22:13AM +0100, Steven Price wrote:
> On 02/05/2024 19:38, Boris Brezillon wrote:
> > This way get NULL derefs instead of use-after-free if the FW VM is
> > referenced after the device has been unplugged.
> > 
> > Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> 
> Reviewed-by: Steven Price <steven.price at arm.com>

Acked-by: Liviu Dudau <liviu.dudau at arm.com>

> 
> > ---
> >  drivers/gpu/drm/panthor/panthor_fw.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
> > index b41685304a83..93165961a6b5 100644
> > --- a/drivers/gpu/drm/panthor/panthor_fw.c
> > +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> > @@ -1141,6 +1141,7 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
> >  	 * state to keep the active_refcnt balanced.
> >  	 */
> >  	panthor_vm_put(ptdev->fw->vm);
> > +	ptdev->fw->vm = NULL;
> >  
> >  	panthor_gpu_power_off(ptdev, L2, ptdev->gpu_info.l2_present, 20000);
> >  }
> 

-- 
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