Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751594AbcDKDB4 (ORCPT ); Sun, 10 Apr 2016 23:01:56 -0400 Received: from mailgw01.mediatek.com ([218.249.47.110]:59010 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750932AbcDKDBz (ORCPT ); Sun, 10 Apr 2016 23:01:55 -0400 Message-ID: <1460343705.10419.12.camel@mhfsdcap03> Subject: Re: [PATCH] usb: core: buffer: avoid NULL pointer dereferrence From: chunfeng yun To: Greg Kroah-Hartman CC: , , , Date: Mon, 11 Apr 2016 11:01:45 +0800 In-Reply-To: <20160408140701.GA3547@kroah.com> References: <1460106483-24793-1-git-send-email-chunfeng.yun@mediatek.com> <20160408140701.GA3547@kroah.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 553 Lines: 18 On Fri, 2016-04-08 at 07:07 -0700, Greg Kroah-Hartman wrote: > On Fri, Apr 08, 2016 at 05:08:03PM +0800, Chunfeng Yun wrote: > > NULL pointer dereferrence will happen when class driver > > wants to allocate zero length buffer and pool_max[0] > > can't be used, so skip reserved pool in this case. > > Why would a driver want to allocate a 0 length buffer? What driver does > this? It's misc/usbtest.c > > Shouldn't we fix that issue instead? I don't know which way is better, but it seems simple to fix it up in buffer.c > > thanks, > > greg k-h