[PATCH] media: vim2m: fix reference leak on failed device registration

[Guangshuo Li]

When platform_device_register() fails in vim2m_init(), the embedded
struct device in vim2m_pdev has already been initialized by
device_initialize(), but the failure path returns the error without
dropping the device reference for the current platform device:

  vim2m_init()
    -> platform_device_register(&vim2m_pdev)
       -> device_initialize(&vim2m_pdev.dev)
       -> setup_pdev_dma_masks(&vim2m_pdev)
       -> platform_device_add(&vim2m_pdev)

This leads to a reference leak when platform_device_register() fails.
Fix this by calling platform_device_put() before returning the error.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fixes: 1f923a42033ad ("[media] mem2mem_testdev: rename to vim2m")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Guangshuo Li <lgs201920130244@xxxxxxxxx>
---
 drivers/media/test-drivers/vim2m.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/test-drivers/vim2m.c b/drivers/media/test-drivers/vim2m.c
index bb2dd11eef0e..80dc7edcbb5e 100644
--- a/drivers/media/test-drivers/vim2m.c
+++ b/drivers/media/test-drivers/vim2m.c
@@ -1601,8 +1601,10 @@ static int __init vim2m_init(void)
 	int ret;
 
 	ret = platform_device_register(&vim2m_pdev);
-	if (ret)
+	if (ret) {
+		platform_device_put(&vim2m_pdev);
 		return ret;
+	}
 
 	ret = platform_driver_register(&vim2m_pdrv);
 	if (ret)
-- 
2.43.0