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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 23918C3A59F for ; Mon, 26 Aug 2019 13:06:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA40E217F5 for ; Mon, 26 Aug 2019 13:05:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730828AbfHZNF6 (ORCPT ); Mon, 26 Aug 2019 09:05:58 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:46912 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730241AbfHZNF6 (ORCPT ); Mon, 26 Aug 2019 09:05:58 -0400 Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id B0F8428BD6A; Mon, 26 Aug 2019 14:05:56 +0100 (BST) Date: Mon, 26 Aug 2019 15:05:53 +0200 From: Boris Brezillon To: Wenwen Wang Cc: Miquel Raynal , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Vignesh Raghavendra , Boris Brezillon , Frieder Schrempf , Thomas Gleixner , Kate Stewart , Randy Dunlap , linux-mtd@lists.infradead.org (open list:NAND FLASH SUBSYSTEM), linux-kernel@vger.kernel.org (open list) Subject: Re: [PATCH v2] mtd: rawnand: Fix a memory leak bug Message-ID: <20190826150553.3f758c84@collabora.com> In-Reply-To: <1566182765-7150-1-git-send-email-wenwen@cs.uga.edu> References: <1566182765-7150-1-git-send-email-wenwen@cs.uga.edu> Organization: Collabora X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 18 Aug 2019 21:46:04 -0500 Wenwen Wang wrote: > In nand_scan_bbt(), a temporary buffer 'buf' is allocated through > vmalloc(). However, if check_create() fails, 'buf' is not deallocated, > leading to a memory leak bug. To fix this issue, free 'buf' before > returning the error. > > Signed-off-by: Wenwen Wang > --- > drivers/mtd/nand/raw/nand_bbt.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/raw/nand_bbt.c b/drivers/mtd/nand/raw/nand_bbt.c > index 2ef15ef..96045d6 100644 > --- a/drivers/mtd/nand/raw/nand_bbt.c > +++ b/drivers/mtd/nand/raw/nand_bbt.c > @@ -1232,7 +1232,7 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd) > if (!td) { > if ((res = nand_memory_bbt(this, bd))) { > pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n"); > - goto err; > + goto err_free_bbt; > } > return 0; > } > @@ -1245,7 +1245,7 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd) > buf = vmalloc(len); > if (!buf) { > res = -ENOMEM; > - goto err; > + goto err_free_bbt; > } > > /* Is the bbt at a given page? */ > @@ -1258,7 +1258,7 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd) > > res = check_create(this, buf, bd); I know it's too late, but calling vfree(buf); here > if (res) > - goto err; > + goto err_free_buf; > > /* Prevent the bbt regions from erasing / writing */ > mark_bbt_region(this, td); > @@ -1268,7 +1268,9 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd) > vfree(buf); instead of here would have fixed the leak without the need for an extra err label. > return 0; > > -err: > +err_free_buf: > + vfree(buf); > +err_free_bbt: > kfree(this->bbt); > this->bbt = NULL; > return res;