[PATCH 1/5] misc: eeprom: digsy_mtc: fix reference leak on failed device registration

[Vastargazing <vebohr@gmail.com>]

When platform_device_register() fails in digsy_mtc_eeprom_devices_init(),
the embedded struct device has already been initialized by
device_initialize() inside platform_device_register(). The failure path
cleans up the software node but returns the error without dropping the
device reference:

  digsy_mtc_eeprom_devices_init()
    -> platform_device_register(&digsy_mtc_eeprom)
       -> device_initialize(&digsy_mtc_eeprom.dev)   /* kref = 1 */
       -> platform_device_add(&digsy_mtc_eeprom)     /* fails */
    <- returns error, kref still 1, reference leaked

Per platform_device_register() kernel-doc:

  NOTE: _Never_ directly free @pdev after calling this function, even if
  it returned an error! Always use platform_device_put() to give up the
  reference initialised in this function instead.

Fix this by calling platform_device_put() in the error branch before
removing the software node.

Fixes: 469dded18391 ("misc/eeprom: add eeprom access driver for digsy_mtc board")
Cc: stable@vger.kernel.org
Assisted-by: GitHub Copilot (Claude Sonnet 4.5)
Signed-off-by: Vastargazing <vebohr@gmail.com>
---
 drivers/misc/eeprom/digsy_mtc_eeprom.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/eeprom/digsy_mtc_eeprom.c b/drivers/misc/eeprom/digsy_mtc_eeprom.c
index ee58f7ce5bfa..4ca3e567c49d 100644
--- a/drivers/misc/eeprom/digsy_mtc_eeprom.c
+++ b/drivers/misc/eeprom/digsy_mtc_eeprom.c
@@ -89,8 +89,10 @@ static int __init digsy_mtc_eeprom_devices_init(void)
 		return ret;
 
 	ret = platform_device_register(&digsy_mtc_eeprom);
-	if (ret)
+	if (ret) {
+		platform_device_put(&digsy_mtc_eeprom);
 		device_remove_software_node(&digsy_mtc_eeprom.dev);
+	}
 
 	return ret;
 }
-- 
2.51.0