From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 929A8C43144 for ; Thu, 28 Jun 2018 11:01:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5551123D15 for ; Thu, 28 Jun 2018 11:01:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5551123D15 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965419AbeF1LBW (ORCPT ); Thu, 28 Jun 2018 07:01:22 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54480 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934000AbeF1LBV (ORCPT ); Thu, 28 Jun 2018 07:01:21 -0400 Received: from localhost (unknown [104.153.224.166]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 94F4686A; Thu, 28 Jun 2018 11:01:17 +0000 (UTC) Date: Thu, 28 Jun 2018 19:52:41 +0900 From: Greg Kroah-Hartman To: Alan Stern Cc: Zhouyang Jia , linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] usb: storage: add error handling for kcalloc Message-ID: <20180628105241.GC5191@kroah.com> References: <20180625123326.GA14987@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 25, 2018 at 11:22:34AM -0400, Alan Stern wrote: > On Mon, 25 Jun 2018, Greg Kroah-Hartman wrote: > > > On Thu, Jun 14, 2018 at 09:29:11PM +0800, Zhouyang Jia wrote: > > > When kcalloc fails, the lack of error-handling code may > > > cause unexpected results. > > > > > > This patch adds error-handling code after calling kcalloc. > > > > > > Signed-off-by: Zhouyang Jia > > > Acked-by: Alan Stern > > > --- > > > v1->v2: > > > - Remove pr_warn statement. > > > --- > > > drivers/usb/storage/alauda.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c > > > index 900591d..4e17609 100644 > > > --- a/drivers/usb/storage/alauda.c > > > +++ b/drivers/usb/storage/alauda.c > > > @@ -437,6 +437,9 @@ static int alauda_init_media(struct us_data *us) > > > + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift); > > > MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > > > MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO); > > > + if ((MEDIA_INFO(us).pba_to_lba == NULL) > > > + || (MEDIA_INFO(us).lba_to_pba == NULL)) > > > + return USB_STOR_TRANSPORT_ERROR; > > > > You just leaked memory if only one of these succeeded :( > > That's not really true. The memory gets deallocated later on in any > case, when alauda_info_destructor() calls alauda_free_maps() if not > before. > > More troubling is the fact that this routine (i.e, alauda_init_media) > gets called from only one place, in alauda_check_media, and the caller > completely ignores the return value! Furthermore, the caller always > returns USB_STOR_TRANSPORT_FAILED. > > So on the whole, I don't think this patch is going to make any > difference to the driver's operation. Ok, I'm just going to drop it then. thanks, greg k-h