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

[Lance Yang <lance.yang@linux.dev>]

On 2026/6/9 21:19, David Hildenbrand (Arm) wrote:
> On 6/9/26 15:12, ranxiaokai627@163.com wrote:
>> From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
>>
>> 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@zte.com.cn>
>> ---
>>   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@gmail.com/

Right, the same issue :) There is a v2:

https://lore.kernel.org/linux-mm/20260412175428.2613383-1-lgs201920130244@gmail.com/

Still pending, though ...