linux-kernel - Re: [PATCH] kobject_set_name

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Message-ID: <m18wjeqven.fsf@fess.ebiederm.org>
Date:	Fri, 26 Jun 2009 19:10:08 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Sergey Senozhatsky <sergey.senozhatsky@...l.by>
Cc:	Greg KH <gregkh@...e.de>, Kay Sievers <kay.sievers@...y.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kobject_set_name_vargs memory leak

Sergey Senozhatsky <sergey.senozhatsky@...l.by> writes:

> On (06/26/09 07:49), Greg KH wrote:
>> We've been through this before (search lkml archives).  If kvasprintf
>> fails, then we don't want to free old_name, as the caller might want to
>> do something with it.
>> 
>> Or something along those lines, I can't remember the exact reasoning
>> this early in the morning.
>> 
>> Kay, do you remember?
>>
> I found.
> http://lkml.org/lkml/2009/5/11/11
>
>>kobject with name set before should not come into this function,
>>kobject_rename should be used instead.
>
> It's just would be safer to kfree or restore I guess.

Yes.  There does seem to be a good point in there that the code should be:
BUG_ON(kobj->name);

And otherwise simply not handle old_name at all.

Eric
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