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From:   Qinglang Miao <miaoqinglang@huawei.com>
To:     =?UTF-8?q?=C5=81ukasz=20Stelmach?= <l.stelmach@samsung.com>,
        "Krzysztof Kozlowski" <krzk@kernel.org>
CC:     <linux-samsung-soc@vger.kernel.org>,
        <linux-crypto@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>,
        Qinglang Miao <miaoqinglang@huawei.com>
Subject: [PATCH] hwrng: exynos - fix reference leak in exynos_trng_probe
Date:   Fri, 27 Nov 2020 17:44:46 +0800
Message-ID: <20201127094446.121277-1-miaoqinglang@huawei.com>
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Precedence: bulk

pm_runtime_get_sync will increment pm usage counter even it
failed. Forgetting to putting operation will result in a
reference leak here.

A new function pm_runtime_resume_and_get is introduced in
[0] to keep usage counter balanced. So We fix the reference
leak by replacing it with new funtion.

[0] dd8088d5a896 ("PM: runtime: Add  pm_runtime_resume_and_get to deal with usage counter")

Fixes: 6cd225cc5d8a ("hwrng: exynos - add Samsung Exynos True RNG driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
---
 drivers/char/hw_random/exynos-trng.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c
index 8e1fe3f8d..666246bc8 100644
--- a/drivers/char/hw_random/exynos-trng.c
+++ b/drivers/char/hw_random/exynos-trng.c
@@ -132,7 +132,7 @@ static int exynos_trng_probe(struct platform_device *pdev)
 		return PTR_ERR(trng->mem);
 
 	pm_runtime_enable(&pdev->dev);
-	ret = pm_runtime_get_sync(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Could not get runtime PM.\n");
 		goto err_pm_get;
-- 
2.23.0