From patchwork Wed Nov 28 03:07:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lu Fengqi X-Patchwork-Id: 10701743 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 022C6181D for ; Wed, 28 Nov 2018 03:07:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E640A2C854 for ; Wed, 28 Nov 2018 03:07:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DA8592C85F; Wed, 28 Nov 2018 03:07:41 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,SUBJ_OBFU_PUNCT_FEW autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 913CB2C854 for ; Wed, 28 Nov 2018 03:07:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727019AbeK1OHk (ORCPT ); Wed, 28 Nov 2018 09:07:40 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:3979 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726847AbeK1OHk (ORCPT ); Wed, 28 Nov 2018 09:07:40 -0500 X-IronPort-AV: E=Sophos;i="5.56,289,1539619200"; d="scan'208";a="48766435" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 28 Nov 2018 11:07:37 +0800 Received: from G08CNEXCHPEKD01.g08.fujitsu.local (unknown [10.167.33.80]) by cn.fujitsu.com (Postfix) with ESMTP id 9554E4B7349D for ; Wed, 28 Nov 2018 11:07:37 +0800 (CST) Received: from fnst.lan (10.167.226.155) by G08CNEXCHPEKD01.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.408.0; Wed, 28 Nov 2018 11:07:43 +0800 From: Lu Fengqi To: Subject: [RFC PATCH] btrfs: drop file privileges in btrfs_clone_files Date: Wed, 28 Nov 2018 11:07:31 +0800 Message-ID: <20181128030731.10288-1-lufq.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.19.2 MIME-Version: 1.0 X-Originating-IP: [10.167.226.155] X-yoursite-MailScanner-ID: 9554E4B7349D.A75BA X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: lufq.fnst@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The generic/513 tell that cloning into a file did not strip security privileges (suid, capabilities) like a regular write would. Signed-off-by: Lu Fengqi --- The xfs and ocfs2 call generic_remap_file_range_prep to drop file privileges, I'm not sure whether btrfs should do the same thing. Any suggestion? fs/btrfs/ioctl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 410c7e007ba8..bc33c480603b 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4312,6 +4312,10 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src, goto out_unlock; } + ret = file_remove_privs(file); + if (ret) + goto out_unlock; + if (destoff > inode->i_size) { ret = btrfs_cont_expand(inode, inode->i_size, destoff); if (ret)