From patchwork Mon Mar 15 13:54:00 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: 401260 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=-24.0 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, MENTIONS_GIT_HOSTING, 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 7E61DC2BB1F for ; Mon, 15 Mar 2021 14:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 516DC64DAD for ; Mon, 15 Mar 2021 14:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234578AbhCOOGJ (ORCPT ); Mon, 15 Mar 2021 10:06:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:37582 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233408AbhCOOBj (ORCPT ); Mon, 15 Mar 2021 10:01:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CAC4664E4D; Mon, 15 Mar 2021 14:01:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816874; bh=/Ddd2zPl42t0KPISs+Dxeg/qgBi4KA8gGxKbfY4SnUE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qGR8Q++AJpaR5qaqdBApDgqF1xdqnpbGcgzC3/XIdr+5+C8VIs7xJhbk/Kv7npEkK QbWpNaam60Y4ZvDdpE8Wrs1PH/AamD6zlC/MFgt5On1zIzXIQTonAz6jLfjEvj8DSt 3sGWSoGaNVMDkmL9PNxryOdQE5HTFiCITKqsQUJw= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Eric W. Biederman" Subject: [PATCH 5.11 177/306] Revert 95ebabde382c ("capabilities: Dont allow writing ambiguous v3 file capabilities") Date: Mon, 15 Mar 2021 14:54:00 +0100 Message-Id: <20210315135513.599831367@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135507.611436477@linuxfoundation.org> References: <20210315135507.611436477@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Eric W. Biederman commit 3b0c2d3eaa83da259d7726192cf55a137769012f upstream. It turns out that there are in fact userspace implementations that care and this recent change caused a regression. https://github.com/containers/buildah/issues/3071 As the motivation for the original change was future development, and the impact is existing real world code just revert this change and allow the ambiguity in v3 file caps. Cc: stable@vger.kernel.org Fixes: 95ebabde382c ("capabilities: Don't allow writing ambiguous v3 file capabilities") Signed-off-by: Eric W. Biederman Signed-off-by: Greg Kroah-Hartman --- security/commoncap.c | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) --- a/security/commoncap.c +++ b/security/commoncap.c @@ -500,8 +500,7 @@ int cap_convert_nscap(struct dentry *den __u32 magic, nsmagic; struct inode *inode = d_backing_inode(dentry); struct user_namespace *task_ns = current_user_ns(), - *fs_ns = inode->i_sb->s_user_ns, - *ancestor; + *fs_ns = inode->i_sb->s_user_ns; kuid_t rootid; size_t newsize; @@ -524,15 +523,6 @@ int cap_convert_nscap(struct dentry *den if (nsrootid == -1) return -EINVAL; - /* - * Do not allow allow adding a v3 filesystem capability xattr - * if the rootid field is ambiguous. - */ - for (ancestor = task_ns->parent; ancestor; ancestor = ancestor->parent) { - if (from_kuid(ancestor, rootid) == 0) - return -EINVAL; - } - newsize = sizeof(struct vfs_ns_cap_data); nscap = kmalloc(newsize, GFP_ATOMIC); if (!nscap)