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 689A7C3DA79 for ; Mon, 26 Dec 2022 14:59:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231610AbiLZO7X (ORCPT ); Mon, 26 Dec 2022 09:59:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbiLZO7V (ORCPT ); Mon, 26 Dec 2022 09:59:21 -0500 Received: from relayaws-01.paragon-software.com (relayaws-01.paragon-software.com [35.157.23.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1161E1138 for ; Mon, 26 Dec 2022 06:59:19 -0800 (PST) Received: from relayfre-01.paragon-software.com (unknown [172.30.72.12]) by relayaws-01.paragon-software.com (Postfix) with ESMTPS id B37902113; Mon, 26 Dec 2022 14:55:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paragon-software.com; s=mail; t=1672066548; bh=Fn1Dqc6XWORUjQACbPZss3I5gZqdvuNA6MIHW/CYL2A=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=aKTd4fLrVdz1puMuzrws7uhWhqw8LtUC67H+CAu1hb7x+HRbqtGRTfWrlEfkbvxYg eYRTU2Pf0syPc40qMoXjUIoER3bQcbNX+bgS/ZoFWyewsji+JySeimSrz4S/AP0gkF 148Cfu+WoTm8mQ/lwSvC0bzSZPuwh5AlBiDYJJ+o= Received: from dlg2.mail.paragon-software.com (vdlg-exch-02.paragon-software.com [172.30.1.105]) by relayfre-01.paragon-software.com (Postfix) with ESMTPS id 095DB212B; Mon, 26 Dec 2022 14:59:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paragon-software.com; s=mail; t=1672066758; bh=Fn1Dqc6XWORUjQACbPZss3I5gZqdvuNA6MIHW/CYL2A=; h=Date:Subject:To:CC:References:From:In-Reply-To; b=TZ37FJ2QGQWLGMz6DttrSwABzxjJmG9h786gsmvKJIarP2P5dogya8kcAFqIyRxfy WY4PDLRRmgE3FA8oL3clg7Z07r1KBeKi0OTJcF5CjYSMvJTzeO7+wfPEXMWk3HW2iW vVXaXoRWYlTGja7hwJWot6hfUA6VngeeV3/NhLoE= Received: from [192.168.211.153] (192.168.211.153) by vdlg-exch-02.paragon-software.com (172.30.1.105) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.7; Mon, 26 Dec 2022 17:59:17 +0300 Message-ID: <718222b6-0291-dcdc-30d8-9b2a7e4e434c@paragon-software.com> Date: Mon, 26 Dec 2022 18:59:16 +0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH] fs/ntfs3: Fix null-ptr-deref on inode->i_op in ntfs_lookup() To: Peng Zhang , CC: , , , , References: <20221125102159.91591-1-zhangpeng362@huawei.com> Content-Language: en-US From: Konstantin Komarov In-Reply-To: <20221125102159.91591-1-zhangpeng362@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.211.153] X-ClientProxiedBy: vobn-exch-01.paragon-software.com (172.30.72.13) To vdlg-exch-02.paragon-software.com (172.30.1.105) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25.11.2022 14:21, Peng Zhang wrote: > From: ZhangPeng > > Syzbot reported a null-ptr-deref bug: > > ntfs3: loop0: Different NTFS' sector size (1024) and media sector size > (512) > ntfs3: loop0: Mark volume as dirty due to NTFS errors > general protection fault, probably for non-canonical address > 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > RIP: 0010:d_flags_for_inode fs/dcache.c:1980 [inline] > RIP: 0010:__d_add+0x5ce/0x800 fs/dcache.c:2796 > Call Trace: > > d_splice_alias+0x122/0x3b0 fs/dcache.c:3191 > lookup_open fs/namei.c:3391 [inline] > open_last_lookups fs/namei.c:3481 [inline] > path_openat+0x10e6/0x2df0 fs/namei.c:3688 > do_filp_open+0x264/0x4f0 fs/namei.c:3718 > do_sys_openat2+0x124/0x4e0 fs/open.c:1310 > do_sys_open fs/open.c:1326 [inline] > __do_sys_open fs/open.c:1334 [inline] > __se_sys_open fs/open.c:1330 [inline] > __x64_sys_open+0x221/0x270 fs/open.c:1330 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > If the MFT record of ntfs inode is not a base record, inode->i_op can be > NULL. And a null-ptr-deref may happen: > > ntfs_lookup() > dir_search_u() # inode->i_op is set to NULL > d_splice_alias() > __d_add() > d_flags_for_inode() # inode->i_op->get_link null-ptr-deref > > Fix this by adding a Check on inode->i_op before calling the > d_splice_alias() function. > > Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") > Reported-by: syzbot+a8f26a403c169b7593fe@syzkaller.appspotmail.com > Signed-off-by: ZhangPeng > --- > fs/ntfs3/namei.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c > index bc22cc321a74..7760aedc0672 100644 > --- a/fs/ntfs3/namei.c > +++ b/fs/ntfs3/namei.c > @@ -86,6 +86,16 @@ static struct dentry *ntfs_lookup(struct inode *dir, struct dentry *dentry, > __putname(uni); > } > > + /* > + * Check for a null pointer > + * If the MFT record of ntfs inode is not a base record, inode->i_op can be NULL. > + * This causes null pointer dereference in d_splice_alias(). > + */ > + if (!IS_ERR(inode) && inode->i_op == NULL) { > + iput(inode); > + inode = ERR_PTR(-EINVAL); > + } > + > return d_splice_alias(inode, dentry); > } > Applied, thanks!