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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 4855BC0650E for ; Thu, 4 Jul 2019 07:22:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 193FC216E3 for ; Thu, 4 Jul 2019 07:22:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727286AbfGDHWV (ORCPT ); Thu, 4 Jul 2019 03:22:21 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:57550 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726199AbfGDHWV (ORCPT ); Thu, 4 Jul 2019 03:22:21 -0400 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 47A2D71C5B86DF84055; Thu, 4 Jul 2019 15:22:18 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.211) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 4 Jul 2019 15:22:14 +0800 Subject: Re: [PATCH v3] f2fs: avoid out-of-range memory access To: Ocean Chen , , , References: <20190703153320.203523-1-oceanchen@google.com> From: Chao Yu Message-ID: Date: Thu, 4 Jul 2019 15:22:13 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190703153320.203523-1-oceanchen@google.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/7/3 23:33, Ocean Chen wrote: > blk_off might over 512 due to fs corrupt and should > be checked before being used. > Use ENTRIES_IN_SUM to protect invalid memory access. > > -- > v2: > - fix typo > v3: > - check blk_off before being used > -- > Signed-off-by: Ocean Chen > --- > fs/f2fs/segment.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 8dee063c833f..c3eae3239345 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3401,6 +3401,9 @@ static int read_compacted_summaries(struct f2fs_sb_info *sbi) > if (seg_i->alloc_type == SSR) > blk_off = sbi->blocks_per_seg; > > + if (blk_off >= ENTRIES_IN_SUM) > + return -EFAULT; - scripts/checkpatch.pl will complain such format. - miss to call f2fs_put_page(page, 1) before return. Thanks, > + > for (j = 0; j < blk_off; j++) { > struct f2fs_summary *s; > s = (struct f2fs_summary *)(kaddr + offset); >