Re: [PATCH 1/3] kobject : kobject_set_name_vargs leak fix

[Dave Young]

On Mon, May 11, 2009 at 2:16 PM, Dave Young <hidave.darkstar@xxxxxxxxx> wrote:
> kobject_set_name_vargs will leak the old_name when return -ENOMEM,
> move the kfree(old_name) before the return path.

Hi, greg

I rethought about this problem, does such issue exist really? I means
that kobject->name != NULL scenario.

there's following comments of this function:

 * This sets the name of the kobject.  If you have already added the
 * kobject to the system, you must call kobject_rename() in order to
 * change the name of the kobject

So what if something like :

if (kobject->name) {
 WARN(1, KERN_WARNING, "there's name for kobject already!");
 return -EINVAL;
}

if (!fmt)
 return 0;

>
> Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx>
> ---
> lib/kobject.c | Â Â2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff -uprN linux.old/lib/kobject.c linux.new/lib/kobject.c
> --- linux.old/lib/kobject.c   2009-05-11 13:59:01.000000000 +0800
> +++ linux.new/lib/kobject.c   2009-05-11 13:59:34.000000000 +0800
> @@ -221,6 +221,7 @@ int kobject_set_name_vargs(struct kobjec
> Â Â Â Âif (kobj->name && !fmt)
> Â Â Â Â Â Â Â Âreturn 0;
>
> + Â Â Â kfree(old_name);
> Â Â Â Âkobj->name = kvasprintf(GFP_KERNEL, fmt, vargs);
> Â Â Â Âif (!kobj->name)
> Â Â Â Â Â Â Â Âreturn -ENOMEM;
> @@ -229,7 +230,6 @@ int kobject_set_name_vargs(struct kobjec
> Â Â Â Âwhile ((s = strchr(kobj->name, '/')))
> Â Â Â Â Â Â Â Âs[0] = '!';
>
> - Â Â Â kfree(old_name);
> Â Â Â Âreturn 0;
> Â}
>



-- 
Regards
dave
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