Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751387AbdH1RMn (ORCPT ); Mon, 28 Aug 2017 13:12:43 -0400 Received: from smtp01.smtpout.orange.fr ([80.12.242.123]:25445 "EHLO smtp.smtpout.orange.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751270AbdH1RMm (ORCPT ); Mon, 28 Aug 2017 13:12:42 -0400 X-ME-Helo: [192.168.1.10] X-ME-Date: Mon, 28 Aug 2017 19:12:36 +0200 X-ME-IP: 86.196.182.67 Subject: Re: [PATCH] igb: check memory allocation failure To: "Waskiewicz Jr, Peter" , "Kirsher, Jeffrey T" Cc: "intel-wired-lan@lists.osuosl.org" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" Newsgroups: gmane.linux.kernel,gmane.linux.network,gmane.linux.kernel.janitors References: <20170827063951.5975-1-christophe.jaillet@wanadoo.fr> From: Christophe JAILLET Message-ID: <95a0bc80-8b41-d74f-8059-ae7181493120@wanadoo.fr> Date: Mon, 28 Aug 2017 19:12:30 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1707 Lines: 45 Le 28/08/2017 à 01:09, Waskiewicz Jr, Peter a écrit : > On 8/27/17 2:42 AM, Christophe JAILLET wrote: >> Check memory allocation failures and return -ENOMEM in such cases, as >> already done for other memory allocations in this function. >> >> This avoids NULL pointers dereference. >> >> Signed-off-by: Christophe JAILLET >> --- >> drivers/net/ethernet/intel/igb/igb_main.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c >> index fd4a46b03cc8..837d9b46a390 100644 >> --- a/drivers/net/ethernet/intel/igb/igb_main.c >> +++ b/drivers/net/ethernet/intel/igb/igb_main.c >> @@ -3162,6 +3162,8 @@ static int igb_sw_init(struct igb_adapter *adapter) >> /* Setup and initialize a copy of the hw vlan table array */ >> adapter->shadow_vfta = kcalloc(E1000_VLAN_FILTER_TBL_SIZE, sizeof(u32), >> GFP_ATOMIC); >> + if (!adapter->shadow_vfta) >> + return -ENOMEM; > Looks reasonable to me. > > A larger issue though I see in this function is that if we return > -ENOMEM here, and if we return -ENOMEM from igb_init_interrupt_scheme() > below on failure, we leak adapter->mac_table (and adapter->shadow_vfta > in the latter). We should add a proper unwind to free up the memory on > failure. > > -PJ > Hi, in fact, there is no leak because the only caller of 'igb_sw_init()' (i.e. 'igb_probe()'), already frees these resources in case of error, see [1] These resources are also freed  in 'igb_remove()'. Best reagrds, CJ [1]: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/intel/igb/igb_main.c#n2775