mm/damon/sysfs-schemes: use strscpy() to instead of strncpy()

[PATCH linux-next] mm/damon/sysfs-schemes: use strscpy() to instead of strncpy()

Posted by yang.yang29@zte.com.cn 2 years, 8 months ago

From: Xu Panda <xu.panda@zte.com.cn>

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.

Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
---
 mm/damon/sysfs-schemes.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
index f0dabe3e2dc0..86edca66aab1 100644
--- a/mm/damon/sysfs-schemes.c
+++ b/mm/damon/sysfs-schemes.c
@@ -353,8 +353,7 @@ static ssize_t memcg_path_store(struct kobject *kobj,
 	if (!path)
 		return -ENOMEM;

-	strncpy(path, buf, count);
-	path[count] = '\0';
+	strscpy(path, buf, count + 1);
 	filter->memcg_path = path;
 	return count;
 }
-- 
2.15.2

Re: [PATCH linux-next] mm/damon/sysfs-schemes: use strscpy() to instead of strncpy()

Posted by SeongJae Park 2 years, 8 months ago

Hello Xu,


Thank you for this patch.

On Mon, 9 Jan 2023 19:46:55 +0800 (CST) <yang.yang29@zte.com.cn> wrote:

> From: Xu Panda <xu.panda@zte.com.cn>
> 
> The implementation of strscpy() is more robust and safer.
> That's now the recommended way to copy NUL-terminated strings.
> 
> Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
> Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>

Reviewed-by: SeongJae Park <sj@kernel.org>

Thanks,
SJ

> ---
>  mm/damon/sysfs-schemes.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c
> index f0dabe3e2dc0..86edca66aab1 100644
> --- a/mm/damon/sysfs-schemes.c
> +++ b/mm/damon/sysfs-schemes.c
> @@ -353,8 +353,7 @@ static ssize_t memcg_path_store(struct kobject *kobj,
>  	if (!path)
>  		return -ENOMEM;
> 
> -	strncpy(path, buf, count);
> -	path[count] = '\0';
> +	strscpy(path, buf, count + 1);
>  	filter->memcg_path = path;
>  	return count;
>  }
> -- 
> 2.15.2