linux-kernel - [PATCH] rtc: Fix error handling in devm_rtc_allocate

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Message-Id: <20251109060817.5620-1-make24@iscas.ac.cn>
Date: Sun,  9 Nov 2025 14:08:17 +0800
From: Ma Ke <make24@...as.ac.cn>
To: alexandre.belloni@...tlin.com
Cc: linux-rtc@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	akpm@...ux-foundation.org,
	Ma Ke <make24@...as.ac.cn>,
	stable@...r.kernel.org
Subject: [PATCH] rtc: Fix error handling in devm_rtc_allocate_device

In rtc_allocate_device(), device_initialize() sets the reference count
to 1. In rtc_allocate_device(), when devm_add_action_or_reset() or
dev_set_name() fails after successful device initialization via
device_initialize(), rtc_allocate_device() returns an error without
properly calling put_device() and releasing the reference count.

Add proper error handling that calls put_device() in all error paths
after device_initialize(), ensuring proper resource cleanup.

Found by code review.

Cc: stable@...r.kernel.org
Fixes: 3068a254d551 ("rtc: introduce new registration method")
Signed-off-by: Ma Ke <make24@...as.ac.cn>
---
 drivers/rtc/class.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index b1a2be1f9e3b..db5f33a22b14 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -379,13 +379,17 @@ struct rtc_device *devm_rtc_allocate_device(struct device *dev)
 	rtc->dev.parent = dev;
 	err = devm_add_action_or_reset(dev, devm_rtc_release_device, rtc);
 	if (err)
-		return ERR_PTR(err);
+		goto err_put_device;
 
 	err = dev_set_name(&rtc->dev, "rtc%d", id);
 	if (err)
-		return ERR_PTR(err);
+		goto err_put_device;
 
 	return rtc;
+
+err_put_device:
+	put_device(&rtc->dev);
+	return ERR_PTR(err);
 }
 EXPORT_SYMBOL_GPL(devm_rtc_allocate_device);
 
-- 
2.17.1