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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 406EBC43441 for ; Fri, 23 Nov 2018 12:11:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAE4E206B2 for ; Fri, 23 Nov 2018 12:11:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EAE4E206B2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com 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 S2504138AbeKWWz3 (ORCPT ); Fri, 23 Nov 2018 17:55:29 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:35585 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388020AbeKWWz3 (ORCPT ); Fri, 23 Nov 2018 17:55:29 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id ED7239242D802; Fri, 23 Nov 2018 20:11:23 +0800 (CST) Received: from [127.0.0.1] (10.111.221.165) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.408.0; Fri, 23 Nov 2018 20:11:16 +0800 Subject: Re: [f2fs-dev] [PATCH] f2fs: check memory boundary by insane namelen To: Jaegeuk Kim , , References: <20181115075040.83500-1-jaegeuk@kernel.org> CC: "gongchen (E)" From: Sheng Yong Message-ID: <3d213d40-a4b0-6e60-87b2-81e66866ac4c@huawei.com> Date: Fri, 23 Nov 2018 20:11:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <20181115075040.83500-1-jaegeuk@kernel.org> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.111.221.165] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Jaegeuk and Chao, On 2018/11/15 15:50, Jaegeuk Kim wrote: > If namelen is corrupted to have very long value, fill_dentries can copy > wrong memory area. > Is there any scenario that could hit this corruption? Or this is triggered by fuzzing injection? thanks, Sheng Yong > Signed-off-by: Jaegeuk Kim > --- > fs/f2fs/dir.c | 12 +++++++++++- > 1 file changed, 11 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > index bacc667950b6..c0c845da12fa 100644 > --- a/fs/f2fs/dir.c > +++ b/fs/f2fs/dir.c > @@ -808,6 +808,17 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, > de_name.name = d->filename[bit_pos]; > de_name.len = le16_to_cpu(de->name_len); > > + /* check memory boundary before moving forward */ > + bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); > + if (unlikely(bit_pos > d->max)) { > + f2fs_msg(sbi->sb, KERN_WARNING, > + "%s: corrupted namelen=%d, run fsck to fix.", > + __func__, le16_to_cpu(de->name_len)); > + set_sbi_flag(sbi, SBI_NEED_FSCK); > + err = -EINVAL; > + goto out; > + } > + > if (f2fs_encrypted_inode(d->inode)) { > int save_len = fstr->len; > > @@ -830,7 +841,6 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, > if (readdir_ra) > f2fs_ra_node_page(sbi, le32_to_cpu(de->ino)); > > - bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len)); > ctx->pos = start_pos + bit_pos; > } > out: >