From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id E7D5BA6A for ; Mon, 2 Mar 2015 17:47:26 +0100 (CET) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP; 02 Mar 2015 08:46:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,676,1418112000"; d="scan'208";a="685638849" Received: from orsmsx108.amr.corp.intel.com ([10.22.240.6]) by fmsmga002.fm.intel.com with ESMTP; 02 Mar 2015 08:47:24 -0800 Received: from orsmsx111.amr.corp.intel.com (10.22.240.12) by ORSMSX108.amr.corp.intel.com (10.22.240.6) with Microsoft SMTP Server (TLS) id 14.3.195.1; Mon, 2 Mar 2015 08:47:24 -0800 Received: from fmsmsx116.amr.corp.intel.com (10.18.116.20) by ORSMSX111.amr.corp.intel.com (10.22.240.12) with Microsoft SMTP Server (TLS) id 14.3.195.1; Mon, 2 Mar 2015 08:47:24 -0800 Received: from fmsmsx113.amr.corp.intel.com ([169.254.13.112]) by fmsmsx116.amr.corp.intel.com ([169.254.2.201]) with mapi id 14.03.0195.001; Mon, 2 Mar 2015 08:47:23 -0800 From: "Wiles, Keith" To: "Wodkowski, PawelX" , David Marchand Thread-Topic: [dpdk-dev] [PATCH] eal: prevent dereferencing NULL pointer in rte_eal_devargs_add() Thread-Index: AQHQVPbIh6JtGzjqXUi57tQiLG/hv50JzhiA//+6nQA= Date: Mon, 2 Mar 2015 16:47:23 +0000 Message-ID: References: <1425294562-26015-1-git-send-email-pawelx.wodkowski@intel.com> <54F479EF.4010706@intel.com> In-Reply-To: <54F479EF.4010706@intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.255.66.73] Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH] eal: prevent dereferencing NULL pointer in rte_eal_devargs_add() X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Mar 2015 16:47:27 -0000 On 3/2/15, 8:55 AM, "Wodkowski, PawelX" wrote: >On 2015-03-02 15:40, Wiles, Keith wrote: >> >> >> On 3/2/15, 6:23 AM, "David Marchand" wrote: >> >>> Hello Pawel, >>> >>> On Mon, Mar 2, 2015 at 12:09 PM, Pawel Wodkowski >>> >>> wrote: >>> >>>> On failure devargs->args should not be accesed if devargs is NULL. >>>> >>> >>> accessed. >>> >>> >>>> >>>> Signed-off-by: Pawel Wodkowski >>>> --- >>>> lib/librte_eal/common/eal_common_devargs.c | 7 ++++--- >>>> 1 file changed, 4 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/lib/librte_eal/common/eal_common_devargs.c >>>> b/lib/librte_eal/common/eal_common_devargs.c >>>> index 9b110f7..615945e 100644 >>>> --- a/lib/librte_eal/common/eal_common_devargs.c >>>> +++ b/lib/librte_eal/common/eal_common_devargs.c >>>> @@ -124,12 +124,13 @@ rte_eal_devargs_add(enum rte_devtype devtype, >>>> const >>>> char *devargs_str) >>>> return 0; >>>> >>>> fail: >>>> - if (devargs->args) >>>> - free(devargs->args); >>>> if (buf) >>>> free(buf); >>>> - if (devargs) >>>> + if (devargs) { >>>> + free(devargs->args); >> >> Do you not still need to check for args being NULL before calling free? > >No, there is no need for that. The same for buf. This NOP check is >common practice in DPDK. I woul be good to clean this in whole library >in separate patch set. > >I recommend to read free() doc before doing another 'if (foo !=3D NULL) >free(foo)' > >http://pubs.opengroup.org/onlinepubs/009695399/functions/free.html OK, did not realize this was changed. Do we know if all of the OSes DPDK is built supports this free style? I know that VxWorks did not support this free() method and I did port DPDK to that OS, but it is not a supported platform for DPDK. If some OS does not support passing NULL (and is supported by DPDK) to free, then we need to abstract the free into a macro to allow those systems to work correctly. I would expect using a macro for free would also help if all frees were reworked to not test for NULL. ++Keith > >--=20 >Pawel