From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id A4BBB201 for ; Fri, 17 Feb 2017 16:13:29 +0100 (CET) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga105.jf.intel.com with ESMTP; 17 Feb 2017 07:13:28 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,172,1484035200"; d="scan'208";a="48178457" Received: from bricha3-mobl3.ger.corp.intel.com ([10.237.221.61]) by orsmga002.jf.intel.com with SMTP; 17 Feb 2017 07:13:26 -0800 Received: by (sSMTP sendmail emulation); Fri, 17 Feb 2017 15:13:26 +0000 Date: Fri, 17 Feb 2017 15:13:26 +0000 From: Bruce Richardson To: "Wiles, Keith" Cc: "dev@dpdk.org" Message-ID: <20170217151325.GA116880@bricha3-MOBL3.ger.corp.intel.com> References: <20170217144426.47823-1-keith.wiles@intel.com> <20170217150245.GB8652@bricha3-MOBL3.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Research and =?iso-8859-1?Q?De=ACvel?= =?iso-8859-1?Q?opment?= Ireland Ltd. User-Agent: Mutt/1.7.2 (2016-11-26) Subject: Re: [dpdk-dev] [PATCH] net/tap: fix coverity warning on strncpy X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2017 15:13:30 -0000 On Fri, Feb 17, 2017 at 03:05:40PM +0000, Wiles, Keith wrote: > > > On Feb 17, 2017, at 9:02 AM, Richardson, Bruce wrote: > > > > On Fri, Feb 17, 2017 at 08:44:26AM -0600, Keith Wiles wrote: > >> Calling strncpy with a maximum size argument of 16 bytes on destination > >> array "ifr.ifr_ifrn.ifrn_name" of size 16 bytes might leave the > >> destination string unterminated. > >> > >> Signed-off-by: Keith Wiles > >> --- > >> drivers/net/tap/rte_eth_tap.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c > >> index efc4426..f9938d7 100644 > >> --- a/drivers/net/tap/rte_eth_tap.c > >> +++ b/drivers/net/tap/rte_eth_tap.c > >> @@ -297,7 +297,7 @@ tap_link_set_flags(struct pmd_internals *pmd, short flags, int add) > >> return -1; > >> } > >> memset(&ifr, 0, sizeof(ifr)); > >> - strncpy(ifr.ifr_name, pmd->name, IFNAMSIZ); > >> + strncpy(ifr.ifr_name, pmd->name, IFNAMSIZ-1); > > This is why I always prefer to use snprintf for copying strings, you > > can't avoid null terminating. > > Normally I use snprintf to not sure why I reverted to strncpy. Maybe leftover from a previous driver I used as the template. > Is there a case to be made that DPDK should provide a strlcpy function in the linuxapp EAL? [Assuming we don't want a dependency on libbsd?] I find strncpy a horribly-error prone function to use - worse than strcpy, since it gives a false sense of safety. /Bruce