[PATCH] mfd: syscon: free the allocated name field of struct regmap_config

[PATCH] mfd: syscon: free the allocated name field of struct regmap_config

[Meng.Li]

From: Limeng <Meng.Li@windriver.com>

The commit 529a1101212a("mfd: syscon: Don't free allocated name
for regmap_config") doesn't free the allocated name field of struct
regmap_config, but introduce a memory leak. There is another
commit 94cc89eb8fa5("regmap: debugfs: Fix handling of name string
for debugfs init delays") fixing this debugfs init issue from root
cause. With this fixing, the name field in struct regmap_debugfs_node
is removed. When initialize debugfs for syscon driver, the name
field of struct regmap_config is not used anymore. So, the allocated
name field of struct regmap_config is need to be freed directly after
regmap initialization to avoid memory leak.

Fixes: 529a1101212a("mfd: syscon: Don't free allocated name for regmap_config")
Cc: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Meng Li <Meng.Li@windriver.com>
---
 drivers/mfd/syscon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index ca465794ea9c..df5cebb372a5 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -108,6 +108,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
 	syscon_config.max_register = resource_size(&res) - reg_io_width;
 
 	regmap = regmap_init_mmio(NULL, base, &syscon_config);
+	kfree(syscon_config.name);
 	if (IS_ERR(regmap)) {
 		pr_err("regmap init failed\n");
 		ret = PTR_ERR(regmap);
@@ -144,7 +145,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
 	regmap_exit(regmap);
 err_regmap:
 	iounmap(base);
-	kfree(syscon_config.name);
 err_map:
 	kfree(syscon);
 	return ERR_PTR(ret);
-- 
2.17.1

Re: [PATCH] mfd: syscon: free the allocated name field of struct regmap_config

[Lee Jones]

On Wed, 07 Apr 2021, Meng.Li@windriver.com wrote:

> From: Limeng <Meng.Li@windriver.com>
> 
> The commit 529a1101212a("mfd: syscon: Don't free allocated name
> for regmap_config") doesn't free the allocated name field of struct
> regmap_config, but introduce a memory leak. There is another
> commit 94cc89eb8fa5("regmap: debugfs: Fix handling of name string
> for debugfs init delays") fixing this debugfs init issue from root
> cause. With this fixing, the name field in struct regmap_debugfs_node
> is removed. When initialize debugfs for syscon driver, the name
> field of struct regmap_config is not used anymore. So, the allocated
> name field of struct regmap_config is need to be freed directly after
> regmap initialization to avoid memory leak.
> 
> Fixes: 529a1101212a("mfd: syscon: Don't free allocated name for regmap_config")
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: stable@vger.kernel.org
> Signed-off-by: Meng Li <Meng.Li@windriver.com>
> ---
>  drivers/mfd/syscon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
> index ca465794ea9c..df5cebb372a5 100644
> --- a/drivers/mfd/syscon.c
> +++ b/drivers/mfd/syscon.c
> @@ -108,6 +108,7 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
>  	syscon_config.max_register = resource_size(&res) - reg_io_width;
>  
>  	regmap = regmap_init_mmio(NULL, base, &syscon_config);
> +	kfree(syscon_config.name);
>  	if (IS_ERR(regmap)) {
>  		pr_err("regmap init failed\n");
>  		ret = PTR_ERR(regmap);
> @@ -144,7 +145,6 @@ static struct syscon *of_syscon_register(struct device_node *np, bool check_clk)
>  	regmap_exit(regmap);
>  err_regmap:
>  	iounmap(base);
> -	kfree(syscon_config.name);
>  err_map:
>  	kfree(syscon);
>  	return ERR_PTR(ret);

Would anyone like to have a look at or test this before I merge it?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH] mfd: syscon: free the allocated name field of struct regmap_config

[Lee Jones]

On Wed, 07 Apr 2021, Meng.Li@windriver.com wrote:

> From: Limeng <Meng.Li@windriver.com>
> 
> The commit 529a1101212a("mfd: syscon: Don't free allocated name
> for regmap_config") doesn't free the allocated name field of struct
> regmap_config, but introduce a memory leak. There is another
> commit 94cc89eb8fa5("regmap: debugfs: Fix handling of name string
> for debugfs init delays") fixing this debugfs init issue from root
> cause. With this fixing, the name field in struct regmap_debugfs_node
> is removed. When initialize debugfs for syscon driver, the name
> field of struct regmap_config is not used anymore. So, the allocated
> name field of struct regmap_config is need to be freed directly after
> regmap initialization to avoid memory leak.
> 
> Fixes: 529a1101212a("mfd: syscon: Don't free allocated name for regmap_config")
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: stable@vger.kernel.org
> Signed-off-by: Meng Li <Meng.Li@windriver.com>
> ---
>  drivers/mfd/syscon.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog