[PATCH 4.14 133/193] cpufreq: kirkwood: fix possible object reference leak

From: Greg Kroah-Hartman
Date: Wed May 29 2019 - 23:56:20 EST


[ Upstream commit 7c468966f05ac9c17bb5948275283d34e6fe0660 ]

The call to of_get_child_by_name returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./drivers/cpufreq/kirkwood-cpufreq.c:127:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 118, but without a corresponding object release within this function.
./drivers/cpufreq/kirkwood-cpufreq.c:133:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 118, but without a corresponding object release within this function.

and also do some cleanup:
- of_node_put(np);
- np = NULL;
...
of_node_put(np);

Signed-off-by: Wen Yang <wen.yang99@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/cpufreq/kirkwood-cpufreq.c | 19 +++++++++++--------
1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
index c2dd43f3f5d8a..8d63a6dc8383c 100644
--- a/drivers/cpufreq/kirkwood-cpufreq.c
+++ b/drivers/cpufreq/kirkwood-cpufreq.c
@@ -124,13 +124,14 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
priv.cpu_clk = of_clk_get_by_name(np, "cpu_clk");
if (IS_ERR(priv.cpu_clk)) {
dev_err(priv.dev, "Unable to get cpuclk\n");
- return PTR_ERR(priv.cpu_clk);
+ err = PTR_ERR(priv.cpu_clk);
+ goto out_node;
}

err = clk_prepare_enable(priv.cpu_clk);
if (err) {
dev_err(priv.dev, "Unable to prepare cpuclk\n");
- return err;
+ goto out_node;
}

kirkwood_freq_table[0].frequency = clk_get_rate(priv.cpu_clk) / 1000;
@@ -161,20 +162,22 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
goto out_ddr;
}

- of_node_put(np);
- np = NULL;
-
err = cpufreq_register_driver(&kirkwood_cpufreq_driver);
- if (!err)
- return 0;
+ if (err) {
+ dev_err(priv.dev, "Failed to register cpufreq driver\n");
+ goto out_powersave;
+ }

- dev_err(priv.dev, "Failed to register cpufreq driver\n");
+ of_node_put(np);
+ return 0;

+out_powersave:
clk_disable_unprepare(priv.powersave_clk);
out_ddr:
clk_disable_unprepare(priv.ddr_clk);
out_cpu:
clk_disable_unprepare(priv.cpu_clk);
+out_node:
of_node_put(np);

return err;
--
2.20.1