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=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 D253EC63798 for ; Sun, 15 Nov 2020 10:42:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A700F23A32 for ; Sun, 15 Nov 2020 10:42:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726829AbgKOKmq (ORCPT ); Sun, 15 Nov 2020 05:42:46 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:59336 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726826AbgKOKmK (ORCPT ); Sun, 15 Nov 2020 05:42:10 -0500 Received: from ip5f5af0a0.dynamic.kabel-deutschland.de ([95.90.240.160] helo=wittgenstein.fritz.box) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1keFS1-0000Kt-Dq; Sun, 15 Nov 2020 10:40:05 +0000 From: Christian Brauner To: Alexander Viro , Christoph Hellwig , linux-fsdevel@vger.kernel.org Cc: John Johansen , James Morris , Mimi Zohar , Dmitry Kasatkin , Stephen Smalley , Casey Schaufler , Arnd Bergmann , Andreas Dilger , OGAWA Hirofumi , Geoffrey Thomas , Mrunal Patel , Josh Triplett , Andy Lutomirski , Theodore Tso , Alban Crequy , Tycho Andersen , David Howells , James Bottomley , Jann Horn , Seth Forshee , =?UTF-8?q?St=C3=A9phane=20Graber?= , Aleksa Sarai , Lennart Poettering , "Eric W. Biederman" , smbarber@chromium.org, Phil Estes , Serge Hallyn , Kees Cook , Todd Kjos , Jonathan Corbet , containers@lists.linux-foundation.org, linux-security-module@vger.kernel.org, linux-api@vger.kernel.org, linux-ext4@vger.kernel.org, linux-audit@redhat.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, Christian Brauner , Christoph Hellwig Subject: [PATCH v2 36/39] overlayfs: do not mount on top of idmapped mounts Date: Sun, 15 Nov 2020 11:37:15 +0100 Message-Id: <20201115103718.298186-37-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201115103718.298186-1-christian.brauner@ubuntu.com> References: <20201115103718.298186-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Prevent overlayfs from being mounted on top of idmapped mounts until we have ported it to handle this case and added proper testing for it. Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner --- /* v2 */ patch introduced --- fs/overlayfs/super.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 0d4f2baf6836..3cacc3d3fb65 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -1708,6 +1708,12 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, if (err) goto out_err; + if (mnt_idmapped(stack[i].mnt)) { + err = -EINVAL; + pr_err("idmapped lower layers are currently unsupported\n"); + goto out_err; + } + lower = strchr(lower, '\0') + 1; } @@ -1939,6 +1945,12 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (err) goto out_err; + if (mnt_idmapped(upperpath.mnt)) { + err = -EINVAL; + pr_err("idmapped lower layers are currently unsupported\n"); + goto out_err; + } + err = ovl_get_workdir(sb, ofs, &upperpath); if (err) goto out_err; -- 2.29.2