2022-06-02 04:40:23

by Miaoqian Lin

Subject: [PATCH] memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings

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 <[email protected]>
---
drivers/memory/samsung/exynos5422-dmc.c | 29 +++++++++++++++----------
1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
index 4733e7898ffe..c491cd549644 100644
--- 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 exynos5_dmc *dmc)

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 exynos5_dmc *dmc)
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;
}

--
2.25.1

2022-06-02 13:09:08

by Lukasz Luba

Subject: Re: [PATCH] memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings

On 6/2/22 05:17, Miaoqian Lin wrote:
> 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 <[email protected]>

Thanks for the patch, LGTM.

Reviewed-by: Lukasz Luba <[email protected]>

2022-06-06 09:40:50

by Krzysztof Kozlowski

Subject: Re: [PATCH] memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings

On Thu, 2 Jun 2022 08:17:21 +0400, Miaoqian Lin wrote:
> 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.
>
>

Applied, thanks!

[1/1] memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings
https://git.kernel.org/krzk/linux-mem-ctrl/c/1332661e09304b7b8e84e5edc11811ba08d12abe

Best regards,
--
Krzysztof Kozlowski <[email protected]>