linux-kernel - Re: [PATCH v1] kobject: Restore old behaviour of kobject

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Mon, 3 Aug 2020 10:13:07 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     linux-kernel@...r.kernel.org,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Qu Wenruo <quwenruo.btrfs@....com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Subject: Re: [PATCH v1] kobject: Restore old behaviour of kobject_del(NULL)

On Mon, Aug 03, 2020 at 10:38:59AM +0300, 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@....com>
> Cc: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>  lib/kobject.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/kobject.c b/lib/kobject.c
> index 3afb939f2a1c..f5f5273031d2 100644
> --- a/lib/kobject.c
> +++ b/lib/kobject.c
> @@ -637,7 +637,7 @@ static void __kobject_del(struct kobject *kobj)
>   */
>  void kobject_del(struct kobject *kobj)
>  {
> -	struct kobject *parent = kobj->parent;
> +	struct kobject *parent = kobj ? kobj->parent : NULL;

I _HATE_ "? :" logic, and it obscures the logic in this function, just
add a simple:
	if (!kobj)
		return;

to this function please.

thanks,

greg k-h