Re: [PATCH] mm/huge_memory: fix memory leak when kobject_init_and_add() fails

[David Hildenbrand (Arm)]

On 6/9/26 15:12, ranxiaokai627@xxxxxxx wrote:
> From: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
> 
> As documented in the comments for kobject_init_and_add():
> 
> "If this function returns an error, kobject_put() must be called to
> properly clean up the memory associated with the object.  This is the
> same type of error handling after a call to kobject_add() and kobject
> lifetime rules are the same here."
> 
> This is because kobject_init_and_add() may have already allocated memory
> internally for the kobject name (kobj->name), and leaving the refcount
> at 1 prevents its release callback from being triggered.
> 
> Fixes: 3485b88390b0a ("mm: thp: introduce multi-size THP sysfs interface")
> Signed-off-by: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx>
> ---
>  mm/huge_memory.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 653f2dc03403..601750dbe79f 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -790,11 +790,8 @@ static struct thpsize *thpsize_create(int order, struct kobject *parent)
>  
>  	ret = kobject_init_and_add(&thpsize->kobj, &thpsize_ktype, parent,
>  				   "hugepages-%lukB", size);
> -	if (ret) {
> -		kfree(thpsize);
> -		goto err;
> -	}
> -
> +	if (ret)
> +		goto err_put;
>  
>  	ret = sysfs_add_group(&thpsize->kobj, &any_ctrl_attr_grp);
>  	if (ret)

This looks a lot like:

https://lore.kernel.org/all/20260411062152.2092967-1-lgs201920130244@xxxxxxxxx/

-- 
Cheers,

David