linux-kernel - [PATCH AUTOSEL 5.4 025/266] rtc: mc13xxx: fix a double-unlock issue

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Date:   Wed, 17 Jun 2020 21:12:30 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Qiushi Wu <wu000273@....edu>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Sasha Levin <sashal@...nel.org>, linux-rtc@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 025/266] rtc: mc13xxx: fix a double-unlock issue

From: Qiushi Wu <wu000273@....edu>

[ Upstream commit 8816cd726a4fee197af2d851cbe25991ae19ea14 ]

In function mc13xxx_rtc_probe, the mc13xxx_unlock() is called
before rtc_register_device(). But in the error path of
rtc_register_device(), the mc13xxx_unlock() is called again,
which causes a double-unlock problem. Thus add a call of the
function “mc13xxx_lock” in an if branch for the completion
of the exception handling.

Fixes: e4ae7023e182a ("rtc: mc13xxx: set range")
Signed-off-by: Qiushi Wu <wu000273@....edu>
Link: https://lore.kernel.org/r/20200503182235.1652-1-wu000273@umn.edu
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/rtc/rtc-mc13xxx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-mc13xxx.c b/drivers/rtc/rtc-mc13xxx.c
index afce2c0b4bd6..d6802e6191cb 100644
--- a/drivers/rtc/rtc-mc13xxx.c
+++ b/drivers/rtc/rtc-mc13xxx.c
@@ -308,8 +308,10 @@ static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
 	mc13xxx_unlock(mc13xxx);
 
 	ret = rtc_register_device(priv->rtc);
-	if (ret)
+	if (ret) {
+		mc13xxx_lock(mc13xxx);
 		goto err_irq_request;
+	}
 
 	return 0;
 
-- 
2.25.1