Re: [PATCH v2] kobject: Restore old behaviour of kobject_del(NULL)

[Qu Wenruo <wqu@suse.com>]

On 2020/8/3 下午4:27, Andy Shevchenko wrote:
> The commit 079ad2fb4bf9 ("kobject: Avoid premature parent object freeing in
> kobject_cleanup()") inadvertently dropped a possibility to call kobject_del()
> with NULL pointer. Restore the old behaviour.
> 
> Fixes: 079ad2fb4bf9 ("kobject: Avoid premature parent object freeing in kobject_cleanup()")
> Reported-by: Qu Wenruo <quwenruo.btrfs@gmx.com>

Sorry, I should use my suse mailbox for that.

> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> ---
> v2: replaced ?: with plain conditional (Greg)
>  lib/kobject.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/kobject.c b/lib/kobject.c
> index 3afb939f2a1c..9dce68c378e6 100644
> --- a/lib/kobject.c
> +++ b/lib/kobject.c
> @@ -637,8 +637,12 @@ static void __kobject_del(struct kobject *kobj)
>   */
>  void kobject_del(struct kobject *kobj)
>  {
> -	struct kobject *parent = kobj->parent;
> +	struct kobject *parent;
> +
> +	if (!kobj)
> +		return;
>  
> +	parent = kobj->parent;
>  	__kobject_del(kobj);
>  	kobject_put(parent);
>  }
>