From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758750AbbEaWPi (ORCPT ); Sun, 31 May 2015 18:15:38 -0400 Received: from mail-lb0-f173.google.com ([209.85.217.173]:36563 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758545AbbEaWP2 (ORCPT ); Sun, 31 May 2015 18:15:28 -0400 Message-ID: <556B87FC.5080908@cogentembedded.com> Date: Mon, 01 Jun 2015 01:15:24 +0300 From: Sergei Shtylyov Organization: Cogent Embedded User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Colin King , Greg Kroah-Hartman , Laurent Pinchart , Felipe Balbi , Sudeep Holla , linux-usb@vger.kernel.org CC: linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: isp1760: fix null dereference if kzalloc returns null References: <1433109649-4086-1-git-send-email-colin.king@canonical.com> In-Reply-To: <1433109649-4086-1-git-send-email-colin.king@canonical.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. On 06/01/2015 01:00 AM, Colin King wrote: > From: Colin Ian King > If kzalloc returns null then isp1760_ep_alloc_request performs > a null pointer deference on req. Dereference, not "deference". No, it doesn't. It calculates the address of the 'isp1760_request::req' instead, there's no dereference per se. I suppose this is a first member of the structure, so this function should work correctly in any case. > Check for null to avoid this. > Detected with smatch static analysis: > > drivers/usb/isp1760/isp1760-udc.c:816 isp1760_ep_alloc_request() > error: potential null dereference 'req'. (kzalloc returns null) Well, the change won't hurt anyway, makes things clearer. > Signed-off-by: Colin Ian King WBR, Sergei