[PATCH] memory: emif: fix device_node reference leak on np_ddr

[PATCH] memory: emif: fix device_node reference leak on np_ddr

[Miles Krause]

of_get_memory_device_details() takes a reference on the DDR device
node via of_parse_phandle() and stores it in emif->np_ddr for later
use, but drops that reference without calling of_node_put() on two
error paths: the devm_kzalloc() allocation-failure check and the
is_dev_data_valid() check. Both return NULL immediately, leaking the
node reference each time either failure triggers.

The same reference is also never released on the success path: it is
kept for the life of the bound device (compared against a later
instance's np_ddr in the duplicate-DDR-geometry check) but
emif_remove() never calls of_node_put() on it, leaking it every time
an EMIF device unbinds. of_node_put() on a NULL pointer is a no-op, so
this is also safe for the non-DT get_device_details() path, where
np_ddr is left NULL by devm_kzalloc().

Fixes: e6b42eb6a66c ("memory: emif: add device tree support to emif driver")
Signed-off-by: Miles Krause <mileskrause5200@gmail.com>
---
 drivers/memory/emif.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c
index 2fadad0666b1..44ccc2561835 100644
--- a/drivers/memory/emif.c
+++ b/drivers/memory/emif.c
@@ -922,6 +922,7 @@ static struct emif_data *of_get_memory_device_details(
 	if (!emif || !pd || !dev_info) {
 		dev_err(dev, "%s: Out of memory!!\n",
 			__func__);
+		of_node_put(np_ddr);
 		goto error;
 	}
 
@@ -946,6 +947,7 @@ static struct emif_data *of_get_memory_device_details(
 			pd->device_info->io_width, pd->phy_type, pd->ip_rev,
 			emif->dev)) {
 		dev_err(dev, "%s: invalid device data!!\n", __func__);
+		of_node_put(np_ddr);
 		goto error;
 	}
 	/*
@@ -1140,6 +1142,7 @@ static void emif_remove(struct platform_device *pdev)
 	struct emif_data *emif = platform_get_drvdata(pdev);
 
 	emif_debugfs_exit(emif);
+	of_node_put(emif->np_ddr);
 }
 
 static void emif_shutdown(struct platform_device *pdev)

---
base-commit: 50d05c7c76c96b90462f24debacca971d2e86713
change-id: 20260909-master-1313e6bbb1fc

Best regards,
-- 
Miles Krause <mileskrause5200@gmail.com>