[PATCH v2] drm: Fix object leak in DRM_IOCTL_GEM_CHANGE_HANDLE

[Karol Wachowski]

Add missing drm_gem_object_put() call when drm_gem_object_lookup()
successfully returns an object. This fixes a GEM object reference
leak that can prevent driver modules from unloading when using
prime buffers.

Fixes: 53096728b891 ("drm: Add DRM prime interface to reassign GEM handle")
Signed-off-by: Karol Wachowski <karol.wachow...@linux.intel.com>
---
Changes between v1 and v2:
 - move setting ret value under if branch as suggested in review
 - add Cc: stable 6.18+
---
 drivers/gpu/drm/drm_gem.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index ca1956608261..bcc08a6aebf8 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1010,8 +1010,10 @@ int drm_gem_change_handle_ioctl(struct drm_device *dev, 
void *data,
        if (!obj)
                return -ENOENT;
 
-       if (args->handle == args->new_handle)
-               return 0;
+       if (args->handle == args->new_handle) {
+               ret = 0;
+               goto out;
+       }
 
        mutex_lock(&file_priv->prime.lock);
 
@@ -1043,6 +1045,8 @@ int drm_gem_change_handle_ioctl(struct drm_device *dev, 
void *data,
 
 out_unlock:
        mutex_unlock(&file_priv->prime.lock);
+out:
+       drm_gem_object_put(obj);
 
        return ret;
 }
-- 
2.43.0