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 A4209C7EE22 for ; Mon, 15 May 2023 09:30:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229629AbjEOJa6 (ORCPT ); Mon, 15 May 2023 05:30:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240933AbjEOJaY (ORCPT ); Mon, 15 May 2023 05:30:24 -0400 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88D761BEF for ; Mon, 15 May 2023 02:30:04 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046056;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0VigEqxN_1684143000; Received: from 30.97.49.11(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VigEqxN_1684143000) by smtp.aliyun-inc.com; Mon, 15 May 2023 17:30:02 +0800 Message-ID: Date: Mon, 15 May 2023 17:30:00 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH] erofs: fix null-ptr-deref caused by erofs_xattr_prefixes_init To: Jingbo Xu , xiang@kernel.org, chao@kernel.org, huyue2@coolpad.com, linux-erofs@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org References: <20230515092148.1485-1-jefflexu@linux.alibaba.com> From: Gao Xiang In-Reply-To: <20230515092148.1485-1-jefflexu@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/5/15 02:21, Jingbo Xu wrote: > Fragments and dedup share one feature bit, and thus packed inode may not please use the formal name "dedupe". > exist when fragment feature bit (dedup feature bit exactly) is set, e.g. ^ dedupe > when deduplication feature is in use while fragments feature is not. In > this case, sbi->packed_inode could be NULL while fragments feature bit > is set. > > Fix this by accessing packed inode only when it exists. > > Reported-by: syzbot+902d5a9373ae8f748a94@syzkaller.appspotmail.com > Link: https://syzkaller.appspot.com/bug?extid=902d5a9373ae8f748a94 > Fixes: 9e382914617c ("erofs: add helpers to load long xattr name prefixes") > Signed-off-by: Jingbo Xu > --- > fs/erofs/xattr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c > index cd80499351e0..bbfe7ce170d2 100644 > --- a/fs/erofs/xattr.c > +++ b/fs/erofs/xattr.c > @@ -675,7 +675,7 @@ int erofs_xattr_prefixes_init(struct super_block *sb) > if (!pfs) > return -ENOMEM; > > - if (erofs_sb_has_fragments(sbi)) > + if (sbi->packed_inode) > buf.inode = sbi->packed_inode; > else > erofs_init_metabuf(&buf, sb);