driver_find_device_by_of_node() calls driver_find_device(), which calls
get_device(). get_device() increments the device's reference count,
so driver_find_device_by_of_node() returns a device
with its reference count incremented.
We need to release this reference after usage to avoid a reference leak.

Add put_device(dev) after dev_get_drvdata() to fix the reference leak.

Found via static analysis.

Fixes: f36e789a1f8d ("mfd: altera-sysmgr: Add SOCFPGA System Manager")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/mfd/altera-sysmgr.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/mfd/altera-sysmgr.c b/drivers/mfd/altera-sysmgr.c
index fb5f988e61f3..cb66b2fff536 100644
--- a/drivers/mfd/altera-sysmgr.c
+++ b/drivers/mfd/altera-sysmgr.c
@@ -116,6 +116,7 @@ struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
 		return ERR_PTR(-EPROBE_DEFER);
 
 	sysmgr = dev_get_drvdata(dev);
+	put_device(dev);
 
 	return sysmgr->regmap;
 }
-- 
2.39.5 (Apple Git-154)

On Tue, 28 Oct 2025, Miaoqian Lin wrote:

> driver_find_device_by_of_node() calls driver_find_device(), which calls
> get_device(). get_device() increments the device's reference count,
> so driver_find_device_by_of_node() returns a device
> with its reference count incremented.
> We need to release this reference after usage to avoid a reference leak.
> 
> Add put_device(dev) after dev_get_drvdata() to fix the reference leak.
> 
> Found via static analysis.
> 
> Fixes: f36e789a1f8d ("mfd: altera-sysmgr: Add SOCFPGA System Manager")
> Cc: stable@vger.kernel.org
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>

Looks like Johan beat you to it.

-- 
Lee Jones [李琼斯]