Re: [PATCH] drm/i915: Return NULL on error in active_instance

[Maarten Lankhorst <maarten.lankhorst@linux.intel.com>]

Hi,

On 6/24/26 11:09, Joonas Lahtinen wrote:
> Avoid returning &node->base when node is NULL due to OOM
> during GFP_ATOMIC allocation.
> 
> Discovered using AI-assisted static analysis confirmed by
> Intel Product Security.
> 
> Reported-by: Martin Hodo <martin.hodo@intel.com>
> Fixes: bfaae47db3c0 ("drm/i915: make lockdep slightly happier about execbuf.")
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Simona Vetter <simona.vetter@ffwll.ch>
> Cc: <stable@vger.kernel.org> # v5.13+
> Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> ---
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

>  drivers/gpu/drm/i915/i915_active.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
> index 5cb7a72774a0..aa77def0bc0d 100644
> --- a/drivers/gpu/drm/i915/i915_active.c
> +++ b/drivers/gpu/drm/i915/i915_active.c
> @@ -318,7 +318,7 @@ active_instance(struct i915_active *ref, u64 idx)
>  	 */
>  	node = kmem_cache_alloc(slab_cache, GFP_ATOMIC);
>  	if (!node)
> -		goto out;
> +		goto err;
>  
>  	__i915_active_fence_init(&node->base, NULL, node_retire);
>  	node->ref = ref;
> @@ -332,6 +332,11 @@ active_instance(struct i915_active *ref, u64 idx)
>  	spin_unlock_irq(&ref->tree_lock);
>  
>  	return &node->base;
> +
> +err:
> +	spin_unlock_irq(&ref->tree_lock);
> +
> +	return NULL;
>  }
>  
>  void __i915_active_init(struct i915_active *ref,