From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760637AbZENMif (ORCPT ); Thu, 14 May 2009 08:38:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753859AbZENMi0 (ORCPT ); Thu, 14 May 2009 08:38:26 -0400 Received: from wf-out-1314.google.com ([209.85.200.175]:43003 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753289AbZENMiZ convert rfc822-to-8bit (ORCPT ); Thu, 14 May 2009 08:38:25 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=QMFWyoz1GrkMHJM1Ac45dVfBuHQE/4gX8Qtx43urNzURmWuUaYuQE8GoZtc58uZLNj cmWnKj3BuQpY2R1ysudqt+ierX1CMQGhxOlyqcHsQf1xv4kk4i2/1DspgsUeL3JGDoyA tSD2o+VcvpNmbVy8HVa82kxho0nQ0UzAbuZ3Q= MIME-Version: 1.0 In-Reply-To: References: Date: Thu, 14 May 2009 20:38:26 +0800 Message-ID: Subject: Re: [PATCH 1/3] kobject : kobject_set_name_vargs leak fix From: Ming Lei To: Dave Young Cc: Greg KH , Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2009/5/14 Dave Young : > On Mon, May 11, 2009 at 2:16 PM, Dave Young 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 >> --- >> lib/kobject.c |    2 +- >> 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 >>        if (kobj->name && !fmt) >>                return 0; >> >> +       kfree(old_name); >>        kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); >>        if (!kobj->name) >>                return -ENOMEM; IMO, Greg means it is better that the fix should be : if (!kobj->name) { kobj->name = old_name; return -ENOMEM; } Right? >> @@ -229,7 +230,6 @@ int kobject_set_name_vargs(struct kobjec >>        while ((s = strchr(kobj->name, '/'))) >>                s[0] = '!'; >> >> -       kfree(old_name); >>        return 0; >>  } >> > > > > -- > Regards > dave > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html > Please read the FAQ at  http://www.tux.org/lkml/ > -- Lei Ming