[PATCH v1] rtc: m41t80: clean up watchdog on probe failure

[Yuho Choi <dbgh9129@gmail.com>]

m41t80_probe() registers the watchdog misc device and reboot notifier
before registering the RTC device. If RTC device registration fails,
probe returns without calling m41t80_remove(), leaving the watchdog misc
device and reboot notifier registered.

Both watchdog paths use the global save_client pointer, which can
outlive the failed probe and point at driver state that has been
released by devres.

Unregister the watchdog misc device and reboot notifier before returning
from the RTC registration failure path.

Fixes: 10d0c768cc6d ("rtc: m41t80: fix race conditions")
Signed-off-by: Yuho Choi <dbgh9129@gmail.com>
---
 drivers/rtc/rtc-m41t80.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index b26afef37d9c..f4a30320c6ed 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -1009,9 +1009,17 @@ static int m41t80_probe(struct i2c_client *client)
 
 	rc = devm_rtc_register_device(m41t80_data->rtc);
 	if (rc)
-		return rc;
+		goto err_wdt;
 
 	return 0;
+err_wdt:
+#ifdef CONFIG_RTC_DRV_M41T80_WDT
+	if (m41t80_data->features & M41T80_FEATURE_HT) {
+		misc_deregister(&wdt_dev);
+		unregister_reboot_notifier(&wdt_notifier);
+	}
+#endif
+	return rc;
 }
 
 static void m41t80_remove(struct i2c_client *client)
-- 
2.43.0