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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 19912C432C0 for ; Tue, 3 Dec 2019 13:13:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAFA32070A for ; Tue, 3 Dec 2019 13:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726466AbfLCNNH (ORCPT ); Tue, 3 Dec 2019 08:13:07 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:38946 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725954AbfLCNNG (ORCPT ); Tue, 3 Dec 2019 08:13:06 -0500 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 0A6C04729755A59EEE63; Tue, 3 Dec 2019 21:13:03 +0800 (CST) Received: from [127.0.0.1] (10.133.219.224) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.439.0; Tue, 3 Dec 2019 21:13:01 +0800 Subject: Re: [PATCH] UBI: fix use after free in ubi_remove_volume() To: Wen Yang , Richard Weinberger , Miquel Raynal , Vignesh Raghavendra CC: , , References: <20191130093317.31352-1-wenyang@linux.alibaba.com> From: Hou Tao Message-ID: <65b49705-e28c-e077-c0de-c5167e34d1c5@huawei.com> Date: Tue, 3 Dec 2019 21:13:01 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20191130093317.31352-1-wenyang@linux.alibaba.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.133.219.224] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Reviewed-by: Hou Tao On 2019/11/30 17:33, Wen Yang wrote: > We can't use "vol" after it has been freed. > > Fixes: 493cfaeaa0c9 ("mtd: utilize new cdev_device_add helper function") > Signed-off-by: Wen Yang > Cc: Richard Weinberger > Cc: Miquel Raynal > Cc: Vignesh Raghavendra > Cc: linux-mtd@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/mtd/ubi/vmt.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c > index 139ee13..8ff1478 100644 > --- a/drivers/mtd/ubi/vmt.c > +++ b/drivers/mtd/ubi/vmt.c > @@ -375,7 +375,6 @@ int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl) > } > > cdev_device_del(&vol->cdev, &vol->dev); > - put_device(&vol->dev); > > spin_lock(&ubi->volumes_lock); > ubi->rsvd_pebs -= reserved_pebs; > @@ -388,6 +387,8 @@ int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl) > if (!no_vtbl) > self_check_volumes(ubi); > > + put_device(&vol->dev); > + > return 0; > > out_err: >