[PATCH] cpufreq: s5pv210: fix refcount leak

[PATCH] cpufreq: s5pv210: fix refcount leak

[Shuhao Fu]

In function `s5pv210_cpu_init`, a possible refcount inconsistency has
been identified, causing a resource leak.

Why it is a bug:
1. For every clk_get, there should be a matching clk_put on every
successive error handling path.
2. After calling `clk_get(dmc1_clk)`, variable `dmc1_clk` will not be
freed even if any error happens.

How it is fixed: For every failed path, an extra goto label is added to
ensure `dmc1_clk` will be freed regardlessly.

Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
---
 drivers/cpufreq/s5pv210-cpufreq.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
index 4215621de..ba8a1c964 100644
--- a/drivers/cpufreq/s5pv210-cpufreq.c
+++ b/drivers/cpufreq/s5pv210-cpufreq.c
@@ -518,7 +518,7 @@ static int s5pv210_cpu_init(struct cpufreq_policy *policy)
 
 	if (policy->cpu != 0) {
 		ret = -EINVAL;
-		goto out_dmc1;
+		goto out;
 	}
 
 	/*
@@ -530,7 +530,7 @@ static int s5pv210_cpu_init(struct cpufreq_policy *policy)
 	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
 		pr_err("CPUFreq doesn't support this memory type\n");
 		ret = -EINVAL;
-		goto out_dmc1;
+		goto out;
 	}
 
 	/* Find current refresh counter and frequency each DMC */
@@ -544,6 +544,8 @@ static int s5pv210_cpu_init(struct cpufreq_policy *policy)
 	cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
 	return 0;
 
+out:
+	clk_put(dmc1_clk);
 out_dmc1:
 	clk_put(dmc0_clk);
 out_dmc0:
-- 
2.39.5

Re: [PATCH] cpufreq: s5pv210: fix refcount leak

[Viresh Kumar]

On 06-10-25, 03:31, Shuhao Fu wrote:
> In function `s5pv210_cpu_init`, a possible refcount inconsistency has
> been identified, causing a resource leak.
> 
> Why it is a bug:
> 1. For every clk_get, there should be a matching clk_put on every
> successive error handling path.
> 2. After calling `clk_get(dmc1_clk)`, variable `dmc1_clk` will not be
> freed even if any error happens.
> 
> How it is fixed: For every failed path, an extra goto label is added to
> ensure `dmc1_clk` will be freed regardlessly.
> 
> Signed-off-by: Shuhao Fu <sfual@cse.ust.hk>
> ---
>  drivers/cpufreq/s5pv210-cpufreq.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/s5pv210-cpufreq.c b/drivers/cpufreq/s5pv210-cpufreq.c
> index 4215621de..ba8a1c964 100644
> --- a/drivers/cpufreq/s5pv210-cpufreq.c
> +++ b/drivers/cpufreq/s5pv210-cpufreq.c
> @@ -518,7 +518,7 @@ static int s5pv210_cpu_init(struct cpufreq_policy *policy)
>  
>  	if (policy->cpu != 0) {
>  		ret = -EINVAL;
> -		goto out_dmc1;
> +		goto out;
>  	}
>  
>  	/*
> @@ -530,7 +530,7 @@ static int s5pv210_cpu_init(struct cpufreq_policy *policy)
>  	if ((mem_type != LPDDR) && (mem_type != LPDDR2)) {
>  		pr_err("CPUFreq doesn't support this memory type\n");
>  		ret = -EINVAL;
> -		goto out_dmc1;
> +		goto out;
>  	}
>  
>  	/* Find current refresh counter and frequency each DMC */
> @@ -544,6 +544,8 @@ static int s5pv210_cpu_init(struct cpufreq_policy *policy)
>  	cpufreq_generic_init(policy, s5pv210_freq_table, 40000);
>  	return 0;
>  
> +out:
> +	clk_put(dmc1_clk);
>  out_dmc1:
>  	clk_put(dmc0_clk);
>  out_dmc0:

Applied. Thanks.

-- 
viresh