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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT 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 1930FC43387 for ; Tue, 18 Dec 2018 16:41:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D9A0321873 for ; Tue, 18 Dec 2018 16:41:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545151273; bh=9ocElY8LluPiM2E2mWx2DtTXBQvT5Y4W6ZaiMPnC9Xs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fsI3eWwBZyH3nwfInQhXu65h50aeuGxIh1QC1nsjvBiZOpgU2YsqLV/eOgva/XZ30 Q9H/3z0qo5rlZzHSE+u9W11AoN3SiYpodciQMRFJ7PlWg12UqpMViAhI7oR9rb0V6D 2nhfAWcVh4etSHqSn4X/H3BvYYXukKddAlCVUcVY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727454AbeLRQlM (ORCPT ); Tue, 18 Dec 2018 11:41:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:38488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726718AbeLRQlL (ORCPT ); Tue, 18 Dec 2018 11:41:11 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6DB8421873; Tue, 18 Dec 2018 16:41:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545151270; bh=9ocElY8LluPiM2E2mWx2DtTXBQvT5Y4W6ZaiMPnC9Xs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PQyzeddYZzs4Gz1nDJjWjKqzzaX975Q1qBFfZ3O3Ylt0gneROUDN/V791jJfz6AnZ hOW7l9jd6d48fKt/cx2tgdCJVgOAPEC1o/RN6xcO14H9udt8sx8RLIbC8TC/G39sd7 v2H9eTZzzmp0ePG2+nCPD+GNE1pj163Su9W46m3U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Theodore Y. Tso" , =?UTF-8?q?Maciej=20Zi=C4=99ba?= , Amir Goldstein , Vivek Goyal , Miklos Szeredi Subject: [PATCH 4.19 16/44] ovl: fix missing override creds in link of a metacopy upper Date: Tue, 18 Dec 2018 17:39:28 +0100 Message-Id: <20181218163929.431174234@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20181218163927.119623235@linuxfoundation.org> References: <20181218163927.119623235@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein commit 91ff20f34e94424e586f57f4f593beae16504f86 upstream. Theodore Ts'o reported a v4.19 regression with docker-dropbox: https://marc.info/?l=linux-fsdevel&m=154070089431116&w=2 "I was rebuilding my dropbox Docker container, and it failed in 4.19 with the following error: ... dpkg: error: error creating new backup file \ '/var/lib/dpkg/status-old': Invalid cross-device link" The problem did not reproduce with metacopy feature disabled. The error was caused by insufficient credentials to set "trusted.overlay.redirect" xattr on link of a metacopy file. Reproducer: echo Y > /sys/module/overlay/parameters/redirect_dir echo Y > /sys/module/overlay/parameters/metacopy cd /tmp mkdir l u w m chmod 777 l u touch l/foo ln l/foo l/link chmod 666 l/foo mount -t overlay none -olowerdir=l,upperdir=u,workdir=w m su fsgqa ln m/foo m/bar [ 21.455823] overlayfs: failed to set redirect (-1) ln: failed to create hard link 'm/bar' => 'm/foo':\ Invalid cross-device link Reported-by: Theodore Y. Ts'o Reported-by: Maciej Zięba Fixes: 4120fe64dce4 ("ovl: Set redirect on upper inode when it is linked") Cc: # v4.19 Signed-off-by: Amir Goldstein Acked-by: Vivek Goyal Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/dir.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -652,6 +652,18 @@ static int ovl_symlink(struct inode *dir return ovl_create_object(dentry, S_IFLNK, 0, link); } +static int ovl_set_link_redirect(struct dentry *dentry) +{ + const struct cred *old_cred; + int err; + + old_cred = ovl_override_creds(dentry->d_sb); + err = ovl_set_redirect(dentry, false); + revert_creds(old_cred); + + return err; +} + static int ovl_link(struct dentry *old, struct inode *newdir, struct dentry *new) { @@ -672,7 +684,7 @@ static int ovl_link(struct dentry *old, goto out_drop_write; if (ovl_is_metacopy_dentry(old)) { - err = ovl_set_redirect(old, false); + err = ovl_set_link_redirect(old); if (err) goto out_drop_write; }