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

[Christian König]

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 <d...@kernel.org>

Thanks for looking into this, feel free to add Reviewed-by: Christian 
König <christian.koe...@amd.com> 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;
        }