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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Hulk Robot <hulkci@huawei.com>,
        Qinglang Miao <miaoqinglang@huawei.com>,
        Wolfram Sang <wsa@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 562/677] i2c: stm32f7: fix reference leak when pm_runtime_get_sync fails
Date:   Wed, 12 May 2021 16:50:08 +0200
Message-Id: <20210512144856.063131627@linuxfoundation.org>
In-Reply-To: <20210512144837.204217980@linuxfoundation.org>
References: <20210512144837.204217980@linuxfoundation.org>
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From: Qinglang Miao <miaoqinglang@huawei.com>

[ Upstream commit 2c662660ce2bd3b09dae21a9a9ac9395e1e6c00b ]

The PM reference count is not expected to be incremented on
return in these stm32f7_i2c_xx serious functions.

However, pm_runtime_get_sync will increment the PM reference
count even failed. Forgetting to putting operation will result
in a reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced.

Fixes: ea6dd25deeb5 ("i2c: stm32f7: add PM_SLEEP suspend/resume support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/i2c/busses/i2c-stm32f7.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index c62c815b88eb..318abfa7926b 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1652,7 +1652,7 @@ static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
 	i2c_dev->msg_id = 0;
 	f7_msg->smbus = false;
 
-	ret = pm_runtime_get_sync(i2c_dev->dev);
+	ret = pm_runtime_resume_and_get(i2c_dev->dev);
 	if (ret < 0)
 		return ret;
 
@@ -1698,7 +1698,7 @@ static int stm32f7_i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 	f7_msg->read_write = read_write;
 	f7_msg->smbus = true;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
 		return ret;
 
@@ -1799,7 +1799,7 @@ static int stm32f7_i2c_reg_slave(struct i2c_client *slave)
 	if (ret)
 		return ret;
 
-	ret = pm_runtime_get_sync(dev);
+	ret = pm_runtime_resume_and_get(dev);
 	if (ret < 0)
 		return ret;
 
@@ -1880,7 +1880,7 @@ static int stm32f7_i2c_unreg_slave(struct i2c_client *slave)
 
 	WARN_ON(!i2c_dev->slave[id]);
 
-	ret = pm_runtime_get_sync(i2c_dev->dev);
+	ret = pm_runtime_resume_and_get(i2c_dev->dev);
 	if (ret < 0)
 		return ret;
 
@@ -2273,7 +2273,7 @@ static int stm32f7_i2c_regs_backup(struct stm32f7_i2c_dev *i2c_dev)
 	int ret;
 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
 
-	ret = pm_runtime_get_sync(i2c_dev->dev);
+	ret = pm_runtime_resume_and_get(i2c_dev->dev);
 	if (ret < 0)
 		return ret;
 
@@ -2295,7 +2295,7 @@ static int stm32f7_i2c_regs_restore(struct stm32f7_i2c_dev *i2c_dev)
 	int ret;
 	struct stm32f7_i2c_regs *backup_regs = &i2c_dev->backup_regs;
 
-	ret = pm_runtime_get_sync(i2c_dev->dev);
+	ret = pm_runtime_resume_and_get(i2c_dev->dev);
 	if (ret < 0)
 		return ret;
 
-- 
2.30.2