[PATCH v2] drm/nouveau: Fix memory leaks in debugfs and hwmon init error paths

[liupeng]

In nouveau_debugfs_init(), if nvif_object_ctor() fails, the previously
allocated drm->debugfs is leaked because the function returns the
error code directly.

In nouveau_hwmon_init(), if hwmon_device_register_with_info() fails,
the allocated hwmon structure is leaked because the function returns
the error code directly.

Fix both by freeing the allocated memory and clearing the pointer on
the error paths.

Fixes: b126a200e9db ("drm/nouveau/debugfs: we need a ctrl object for debugfs")
Fixes: b9ed919f1c8f ("drm/nouveau/drm/pm: remove everything except the hwmon 
interfaces to THERM")
Cc: sta...@vger.kernel.org
Signed-off-by: liupeng <liupen...@kylinos.cn>
---
Changes in v2:
- Add Fixes: tags for the commits that introduced the leaks
- Add Cc: sta...@vger.kernel.org for stable backporting

 drivers/gpu/drm/nouveau/nouveau_debugfs.c | 15 ++++++++++++---
 drivers/gpu/drm/nouveau/nouveau_hwmon.c   |  2 ++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_debugfs.c 
b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
index 47d5579c568d..88223931f382 100644
--- a/drivers/gpu/drm/nouveau/nouveau_debugfs.c
+++ b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
@@ -295,13 +295,22 @@ nouveau_drm_debugfs_init(struct drm_minor *minor)
 int
 nouveau_debugfs_init(struct nouveau_drm *drm)
 {
+       int ret;
+
        drm->debugfs = kzalloc_obj(*drm->debugfs);
        if (!drm->debugfs)
                return -ENOMEM;
 
-       return nvif_object_ctor(&drm->client.device.object, "debugfsCtrl", 0,
-                               NVIF_CLASS_CONTROL, NULL, 0,
-                               &drm->debugfs->ctrl);
+       ret = nvif_object_ctor(&drm->client.device.object, "debugfsCtrl", 0,
+                              NVIF_CLASS_CONTROL, NULL, 0,
+                              &drm->debugfs->ctrl);
+       if (ret) {
+               kfree(drm->debugfs);
+               drm->debugfs = NULL;
+               return ret;
+       }
+
+       return 0;
 }
 
 void
diff --git a/drivers/gpu/drm/nouveau/nouveau_hwmon.c 
b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
index 726397ab035d..ffbe7f542ab0 100644
--- a/drivers/gpu/drm/nouveau/nouveau_hwmon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_hwmon.c
@@ -697,6 +697,8 @@ nouveau_hwmon_init(struct drm_device *dev)
        if (IS_ERR(hwmon_dev)) {
                ret = PTR_ERR(hwmon_dev);
                NV_ERROR(drm, "Unable to register hwmon device: %d\n", ret);
+               drm->hwmon = NULL;
+               kfree(hwmon);
                return ret;
        }
 
-- 
2.53.0