From nobody Tue Apr 7 05:21:23 2026 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 AD22EECAAD1 for ; Wed, 31 Aug 2022 16:13:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231302AbiHaQN0 (ORCPT ); Wed, 31 Aug 2022 12:13:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231383AbiHaQNX (ORCPT ); Wed, 31 Aug 2022 12:13:23 -0400 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98982D3E41 for ; Wed, 31 Aug 2022 09:13:21 -0700 (PDT) Received: by mail-pg1-x52e.google.com with SMTP id 78so404750pgb.13 for ; Wed, 31 Aug 2022 09:13:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=2/XdbCrUv8gzI+JX2k2NXC+D9E3l4e2SIhgqVmL688s=; b=f5QU2TxsaHqq0+Tv62FC10+qGUJsEr8NPuARb4jmb+PSyWWm9/cTxOfwL9rqklEsiU lpOIU+hGzwSvrbyPaof+oTZoi+3fafUymzWJOVR0+d/DTc4QNFRmkYysCx48cajI9NVg vBP2omKhKD5vZViL7dIgWNZ+DrdkGTLeP3UHvdI4rtCyWGeR/szG8k/vysZ9Az9U1dqU 4U5zW5knps6TcOVneBucynP2m4TBVEdlHkI2gyupJPm8qmt/ANwU7XPMQTDIEU4/0En6 dPySy37hkxmFMrPlu8oqHrFGRrT5GbVT50pBucuqmbrh4FUGI81rrbHMBE6q7jg6bToI Bepw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=2/XdbCrUv8gzI+JX2k2NXC+D9E3l4e2SIhgqVmL688s=; b=k1BYpbh1uBY7sODma1i6+F+q8OtTCJ5k6ygmcDyp4LfjFjxYhmSzt819buliXdJcFn bmDee9OipOo6gfwzk4f51TQqZkxEse4RI+iM36jc0C6iKSXkKLvyOCgGqPdoJTP1tyCu PgaCu05XnAVe9u8ZEDSH7TLoVz1iLrtfDRM5Dh17TuugJs5pUt+WGHr5fvuObnSearmI mTlM3izFnbHnpCw6UPY2VDtlOAu3AafX4NL3q2/B8y4zcJZ7O0vBw/awGLL6gUxiHGnB YMWDIjnuNqXrMsIXOrP1v1e9ccwQlmUV0NTM/tkawZwSezRfsyZPXz+wSK8SDNQlNt1g cSSw== X-Gm-Message-State: ACgBeo1GvYZXvYx0+gfZ6qLXh8tLiOBa8xsLsXmoWYRaWWB/hP1RR+zK RiLHRMCiS3vZ1EgOv7u/Vac= X-Google-Smtp-Source: AA6agR4g7ANCCZnZLbqBt1B/FVTEl7FACQ3ukgyLFuVCEsDq1UeSAGPQljKMq2loqOHwgS+5Q1prxA== X-Received: by 2002:a05:6a00:2918:b0:535:ea9:791a with SMTP id cg24-20020a056a00291800b005350ea9791amr27095438pfb.54.1661962400574; Wed, 31 Aug 2022 09:13:20 -0700 (PDT) Received: from localhost ([36.112.195.70]) by smtp.gmail.com with ESMTPSA id c7-20020a624e07000000b0052d417039c2sm11439458pfb.133.2022.08.31.09.13.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Aug 2022 09:13:20 -0700 (PDT) From: Hawkins Jiawei To: syzbot+5f8dcabe4a3b2c51c607@syzkaller.appspotmail.com, Anton Altaparmakov Cc: akpm@linux-foundation.org, chenxiaosong2@huawei.com, linux-kernel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, syzkaller-bugs@googlegroups.com, yin31149@gmail.com, 18801353760@163.com, Dan Carpenter Subject: [PATCH v2 3/3] ntfs: check overflow when iterates ATTR_RECORDs Date: Thu, 1 Sep 2022 00:09:38 +0800 Message-Id: <20220831160935.3409-4-yin31149@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220831160935.3409-1-yin31149@gmail.com> References: <20220831160935.3409-1-yin31149@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Kernel will iterates over ATTR_RECORDs in mft record in ntfs_attr_find(). Because the ATTR_RECORDs are next to each other, kernel can get the next ATTR_RECORD from end address of current ATTR_RECORD, through current ATTR_RECORD length field. The problem is that during iteration, when kernel calculates the end address of current ATTR_RECORD, kernel may trigger an integer overflow bug in executing `a =3D (ATTR_RECORD*)((u8*)a + le32_to_cpu(a->length))`. This may wrap, leading to a forever iteration on 32bit systems. This patch solves it by adding some checks on calculating end address of current ATTR_RECORD during iteration. Suggested-by: Dan Carpenter Link: https://lore.kernel.org/all/20220827105842.GM2030@kadam/ Signed-off-by: Hawkins Jiawei --- v1->v2: * Add check bounds on ATTR_RECORD's length suggested by Dan Carpenter. fs/ntfs/attrib.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c index cec4be2a2d23..a3865bc4a0c6 100644 --- a/fs/ntfs/attrib.c +++ b/fs/ntfs/attrib.c @@ -617,6 +617,14 @@ static int ntfs_attr_find(const ATTR_TYPE type, const = ntfschar *name, return -ENOENT; if (unlikely(!a->length)) break; + + /* check whether ATTR_RECORD's length wrap */ + if ((u8 *)a + le32_to_cpu(a->length) < (u8 *)a) + break; + /* check whether ATTR_RECORD's length is within bounds */ + if ((u8 *)a + le32_to_cpu(a->length) > mrec_end) + break; + if (a->type !=3D type) continue; /* --=20 2.25.1