Re: [patch] drm/vmwgfx: fix a NULL dereference

[Daniel Vetter]

On Thu, Jan 28, 2016 at 12:06:46PM +0300, Dan Carpenter wrote:
> We dereference "eaction->event" inside the call to drm_send_event_locked()
> so should hold off on setting it to NULL until afterward.
> 
> Fixes: fb740cf2492c ("drm: Create drm_send_event helpers")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

Oh dear that's embarassing. Thanks for the patch, applied.
-Daniel

> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
> index e0edf14..37c305b 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fence.c
> @@ -880,8 +880,8 @@ static void vmw_event_fence_action_seq_passed(struct vmw_fence_action *action)
>  	}
>  
>  	list_del_init(&eaction->fpriv_head);
> -	eaction->event = NULL;
>  	drm_send_event_locked(dev, eaction->event);
> +	eaction->event = NULL;
>  	spin_unlock_irqrestore(&dev->event_lock, irq_flags);
>  }
>  

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch