From patchwork Mon Mar 1 16:12:52 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 389080 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, 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 7DA1BC433E6 for ; Mon, 1 Mar 2021 20:41:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 211BD601FA for ; Mon, 1 Mar 2021 20:41:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243054AbhCAUlH (ORCPT ); Mon, 1 Mar 2021 15:41:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:50670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240296AbhCAUdx (ORCPT ); Mon, 1 Mar 2021 15:33:53 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CA49860240; Mon, 1 Mar 2021 18:45:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614624321; bh=0EByw8XFbx99sPrjyyssPQod9xfPKCY02JICQmsyRxg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U5RRxyUEJf8SDzmBaUz95UcpV49VHGTO1iQBnGix9nzgqwlTkMaM35w0I3q/kmlAd 0RGF0TRwoAqz7GA8ebIkzh9dkCKGjsOgfQ6b1VE4TkSbpiOCCmmor+vyVibClvypEE Cx8KsRbYGpvZFvI5l69nPZCVkVtOidBjP01xADL0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Labriola , Amir Goldstein , Ondrej Mosnacek , Paul Moore Subject: [PATCH 5.10 524/663] selinux: fix inconsistency between inode_getxattr and inode_listsecurity Date: Mon, 1 Mar 2021 17:12:52 +0100 Message-Id: <20210301161207.767857253@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161141.760350206@linuxfoundation.org> References: <20210301161141.760350206@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Amir Goldstein commit a9ffe682c58aaff643764547f5420e978b6e0830 upstream. When inode has no listxattr op of its own (e.g. squashfs) vfs_listxattr calls the LSM inode_listsecurity hooks to list the xattrs that LSMs will intercept in inode_getxattr hooks. When selinux LSM is installed but not initialized, it will list the security.selinux xattr in inode_listsecurity, but will not intercept it in inode_getxattr. This results in -ENODATA for a getxattr call for an xattr returned by listxattr. This situation was manifested as overlayfs failure to copy up lower files from squashfs when selinux is built-in but not initialized, because ovl_copy_xattr() iterates the lower inode xattrs by vfs_listxattr() and vfs_getxattr(). Match the logic of inode_listsecurity to that of inode_getxattr and do not list the security.selinux xattr if selinux is not initialized. Reported-by: Michael Labriola Tested-by: Michael Labriola Link: https://lore.kernel.org/linux-unionfs/2nv9d47zt7.fsf@aldarion.sourceruckus.org/ Fixes: c8e222616c7e ("selinux: allow reading labels before policy is loaded") Cc: stable@vger.kernel.org#v5.9+ Signed-off-by: Amir Goldstein Reviewed-by: Ondrej Mosnacek Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- security/selinux/hooks.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3414,6 +3414,10 @@ static int selinux_inode_setsecurity(str static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) { const int len = sizeof(XATTR_NAME_SELINUX); + + if (!selinux_initialized(&selinux_state)) + return 0; + if (buffer && len <= buffer_size) memcpy(buffer, XATTR_NAME_SELINUX, len); return len;