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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53846C88CB4 for ; Mon, 12 Jun 2023 14:01:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236507AbjFLOBF (ORCPT ); Mon, 12 Jun 2023 10:01:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236158AbjFLOA5 (ORCPT ); Mon, 12 Jun 2023 10:00:57 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E78210D3 for ; Mon, 12 Jun 2023 07:00:53 -0700 (PDT) Received: from kwepemm600012.china.huawei.com (unknown [172.30.72.55]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QftWK1SPcz18Lc7; Mon, 12 Jun 2023 21:55:57 +0800 (CST) Received: from build.huawei.com (10.175.101.6) by kwepemm600012.china.huawei.com (7.193.23.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 12 Jun 2023 22:00:51 +0800 From: Wenchao Hao To: Jan Kara , CC: , Wenchao Hao Subject: [PATCH 0/2] Fix out-of-bound access if pagecache of udf device is corrupted Date: Tue, 13 Jun 2023 11:22:52 +0800 Message-ID: <20230613032254.1235752-1-haowenchao2@huawei.com> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600012.china.huawei.com (7.193.23.74) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Following steps would cause out-of-bound access and even cause kernel panic when using udf: dd if=/dev/zero of=udf.img bs=1M count=512 mkfs.udf udf.img mount -o loop -t udf udf.img /mnt dd if=/dev/random of=/dev/loop0 bs=512 count=1 seek=128 umount /mnt [if /mnt is mounted on /dev/loop0] It is because we did not check if udf_sb_info->s_lvid_bh is valid in udf_sb_lvidiu(). Although it's illegal to write backend device since filesystem has been mounted, but we should avoid kernel panic if it happened. The first patch add a helper function to check if the data is valid. The second patch just call the helper function, if check failed, return NULL from udf_sb_lvidiu() Wenchao Hao (2): udf: add helper function udf_check_tagged_bh to check tagged page udf:check if buffer head's data when getting lvidiu fs/udf/misc.c | 60 ++++++++++++++++++++++++++++-------------------- fs/udf/super.c | 2 ++ fs/udf/udfdecl.h | 1 + 3 files changed, 38 insertions(+), 25 deletions(-) -- 2.35.3