Re: [PATCH 1/3] drm/nouveau: prime: fix refcount underflow

[Christian König <christian.koenig@xxxxxxx>]

Am 18.07.24 um 18:58 schrieb Danilo Krummrich:
> Calling nouveau_bo_ref() on a nouveau_bo without initializing it (and
> hence the backing ttm_bo) leads to a refcount underflow.
>
> Instead of calling nouveau_bo_ref() in the unwind path of
> drm_gem_object_init(), clean things up manually.
>
> Fixes: ab9ccb96a6e6 ("drm/nouveau: use prime helpers")
> Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>

Thanks for looking into this, feel free to add Reviewed-by: Christian 
König <christian.koenig@xxxxxxx> to this patch.

But since especially patch #3 is not something I can fully judge 
correctness on I can only give an acked-by to the other two.

Regards,
Christian.

> ---
>   drivers/gpu/drm/nouveau/nouveau_prime.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c
> index b58ab595faf8..cd95446d6851 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_prime.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
> @@ -64,7 +64,8 @@ struct drm_gem_object *nouveau_gem_prime_import_sg_table(struct drm_device *dev,
>   	 * to the caller, instead of a normal nouveau_bo ttm reference. */
>   	ret = drm_gem_object_init(dev, &nvbo->bo.base, size);
>   	if (ret) {
> -		nouveau_bo_ref(NULL, &nvbo);
> +		drm_gem_object_release(&nvbo->bo.base);
> +		kfree(nvbo);
>   		obj = ERR_PTR(-ENOMEM);
>   		goto unlock;
>   	}