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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, Miaoqian Lin <linmq006@gmail.com>,
        Lukasz Luba <lukasz.luba@arm.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Subject: [PATCH 5.18 171/181] memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings
Date:   Mon, 27 Jun 2022 13:22:24 +0200
Message-Id: <20220627111949.644119087@linuxfoundation.org>
In-Reply-To: <20220627111944.553492442@linuxfoundation.org>
References: <20220627111944.553492442@linuxfoundation.org>
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From: Miaoqian Lin <linmq006@gmail.com>

commit 1332661e09304b7b8e84e5edc11811ba08d12abe upstream.

of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
This function doesn't call of_node_put() in some error paths.
To unify the structure, Add put_node label and goto it on errors.

Fixes: 6e7674c3c6df ("memory: Add DMC driver for Exynos5422")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20220602041721.64348-1-linmq006@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/memory/samsung/exynos5422-dmc.c |   29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

--- a/drivers/memory/samsung/exynos5422-dmc.c
+++ b/drivers/memory/samsung/exynos5422-dmc.c
@@ -1187,33 +1187,39 @@ static int of_get_dram_timings(struct ex
 
 	dmc->timing_row = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
 					     sizeof(u32), GFP_KERNEL);
-	if (!dmc->timing_row)
-		return -ENOMEM;
+	if (!dmc->timing_row) {
+		ret = -ENOMEM;
+		goto put_node;
+	}
 
 	dmc->timing_data = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
 					      sizeof(u32), GFP_KERNEL);
-	if (!dmc->timing_data)
-		return -ENOMEM;
+	if (!dmc->timing_data) {
+		ret = -ENOMEM;
+		goto put_node;
+	}
 
 	dmc->timing_power = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
 					       sizeof(u32), GFP_KERNEL);
-	if (!dmc->timing_power)
-		return -ENOMEM;
+	if (!dmc->timing_power) {
+		ret = -ENOMEM;
+		goto put_node;
+	}
 
 	dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dmc->dev,
 						 DDR_TYPE_LPDDR3,
 						 &dmc->timings_arr_size);
 	if (!dmc->timings) {
-		of_node_put(np_ddr);
 		dev_warn(dmc->dev, "could not get timings from DT\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto put_node;
 	}
 
 	dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dmc->dev);
 	if (!dmc->min_tck) {
-		of_node_put(np_ddr);
 		dev_warn(dmc->dev, "could not get tck from DT\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto put_node;
 	}
 
 	/* Sorted array of OPPs with frequency ascending */
@@ -1227,13 +1233,14 @@ static int of_get_dram_timings(struct ex
 					     clk_period_ps);
 	}
 
-	of_node_put(np_ddr);
 
 	/* Take the highest frequency's timings as 'bypass' */
 	dmc->bypass_timing_row = dmc->timing_row[idx - 1];
 	dmc->bypass_timing_data = dmc->timing_data[idx - 1];
 	dmc->bypass_timing_power = dmc->timing_power[idx - 1];
 
+put_node:
+	of_node_put(np_ddr);
 	return ret;
 }