[PATCH v1] bus: mhi: ep: Fix device refcount leak on create failure

[Yuho Choi <dbgh9129@gmail.com>]

mhi_ep_create_device() takes one device reference for the UL channel and
another for the DL channel after allocating the transfer device. These
references are normally released by mhi_ep_destroy_device() before the
device itself is removed.

If dev_set_name() or device_add() fails, the error path currently drops
only one reference. The remaining channel references keep the device
from being released and leave the channels associated with a device that
was never registered.

Route both failures through a common unwind path that drops the DL
channel reference, the UL channel reference, and the initial reference
from device_initialize().

Fixes: 297c77a0f273 ("bus: mhi: ep: Add support for creating and destroying MHI EP devices")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
---
 drivers/bus/mhi/ep/main.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 0277e1ab1198..34d3662eb091 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1338,15 +1338,19 @@ static int mhi_ep_create_device(struct mhi_ep_cntrl *mhi_cntrl, u32 ch_id)
 	ret = dev_set_name(&mhi_dev->dev, "%s_%s",
 		     dev_name(&mhi_cntrl->mhi_dev->dev),
 		     mhi_dev->name);
-	if (ret) {
-		put_device(&mhi_dev->dev);
-		return ret;
-	}
+	if (ret)
+		goto err_put_channels;
 
 	ret = device_add(&mhi_dev->dev);
 	if (ret)
-		put_device(&mhi_dev->dev);
+		goto err_put_channels;
+
+	return 0;
 
+err_put_channels:
+	put_device(&mhi_dev->dev); /* DL channel reference */
+	put_device(&mhi_dev->dev); /* UL channel reference */
+	put_device(&mhi_dev->dev); /* device_initialize() reference */
 	return ret;
 }
 
-- 
2.43.0