Re: [PATCH v2] mm: huge_memory: Fix kobject cleanup in thpsize_create error

["Zi Yan" <ziy@nvidia.com>]

On Mon Jul 13, 2026 at 1:41 AM EDT, Hongling Zeng wrote:
> When kobject_init_and_add() fails, the kobject API requires calling
> kobject_put() to properly clean up the memory, not direct kfree().
>
> According to the kobject API documentation, kobject_init_and_add()
> calls kobject_init() internally. If the subsequent kobject_add()
> fails, the kobject has still been initialized and must be cleaned up
> via the reference count mechanism (kobject_put), not direct kfree().
>
> Direct kfree() leaves the kobject's internal state (including the
> reference count and kset membership) uncleaned, which can cause:
>  - Memory leaks of kobject internal structures
>  - Potential use-after-free if there are pending references
>  - Inconsistent state with the rest of the error handling code
>
> This fix matches the pattern used elsewhere in the kernel and in the
> same function (err_put label) which correctly uses kobject_put().
>
> Fixes: 3485b88390b0 ("mm: thp: introduce multi-size THP sysfs interface")
> Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
> Suggested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>
> ---
>  Change in v2:
>  - Use goto err_put instead of kobject_put() + goto err for consistency
>  - Add suggested
> ---
>  mm/huge_memory.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>

LGTM.

Acked-by: Zi Yan <ziy@nvidia.com>



-- 
Best Regards,
Yan, Zi