From patchwork Wed Aug 10 21:36:02 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 657949 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3s8kxd5Xm6z9s9G for ; Thu, 11 Aug 2016 07:36:53 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=cJDpI2IC; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932200AbcHJVgc (ORCPT ); Wed, 10 Aug 2016 17:36:32 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:33952 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751505AbcHJVgI (ORCPT ); Wed, 10 Aug 2016 17:36:08 -0400 Received: by mail-pf0-f194.google.com with SMTP id g202so3478406pfb.1; Wed, 10 Aug 2016 14:36:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=mH8sRkl6cPfgCW0NkIVcW51MBf9yax3ONJJHbDMGyQ8=; b=cJDpI2ICX6zCiM2FCaFOJWPYL6EeoNckIfYjsOC8C4l2Lg1tnGGyqp9aeu+fO1nyV7 3herAJrscJXBkvyb2CcArb1puGbnFKf3GMkt2SQikrNZ6B0/O1B4JFFIWAfHgl0AN/Iw H6arM4ZDYE1rcjRNn+cu0esjJzCW1qYLPuGQR8Iz6S+jDS8LJ/IE43DAqLBFMIMalOyX Ca3Iz8fU+ti9411jG9Mx44V4sHPeSHHeC/Snn9rw12i2RGm1oGWE/tvb+kNtyOv/ZXTt txWpasPvaTadpzVRiAU4Txm5EmwGd7VTbO7d9Spuxew40ps6vD8cjQcqpsiQvi7ywXo0 dNUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=mH8sRkl6cPfgCW0NkIVcW51MBf9yax3ONJJHbDMGyQ8=; b=i2QKYT/0U9sA0IGwdnb7iZPU+ASezaaRDpxbWr6W13PyBTwjGCZHG7okMZmOWtxCJy G4nD6xgYPwxvhaltzBylGyDGr/iXHn7JfES5BANeeVWaiAbaTnDh3m0AdQfgXnc35Lmk oc3xiZJgfzJ5jPysFjMaQ8gY5xMmYAbceBv3O1AHuP6uiR9AdwnRVdviM8kReN1SBEm6 jtE18PeP/X37LajlpBP8+x03KUXBnnu6Yn92HXx7nZRQnFOLBBpt9ue7tjSWoOeG/7zb KdCRQMVEaGeY4X64vcD4706ngIRTrkR9hG6IbAX3Uuft0fpSQHdfbyHtOwamD6oli8UW XOKA== X-Gm-Message-State: AEkoousgD4bbE+7ekQHAoNkvtSRPs3CP5oFVZ/wnz5srNlv94KwC1Vb63Sa0asWJzY8hFA== X-Received: by 10.98.64.93 with SMTP id n90mr10924334pfa.29.1470864967116; Wed, 10 Aug 2016 14:36:07 -0700 (PDT) Received: from dtor-ws.mtv.corp.google.com ([172.22.152.21]) by smtp.gmail.com with ESMTPSA id fj19sm66408660pab.37.2016.08.10.14.36.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 10 Aug 2016 14:36:06 -0700 (PDT) From: Dmitry Torokhov To: "Eric W. Biederman" , "David S. Miller" Cc: Al Viro , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2 3/3] net: make net namespace sysctls belong to container's owner Date: Wed, 10 Aug 2016 14:36:02 -0700 Message-Id: <1470864962-25056-4-git-send-email-dmitry.torokhov@gmail.com> X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: <1470864962-25056-1-git-send-email-dmitry.torokhov@gmail.com> References: <1470864962-25056-1-git-send-email-dmitry.torokhov@gmail.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If net namespace is attached to a user namespace let's make container's root owner of sysctls affecting said network namespace instead of global root. This also allows us to clean up net_ctl_permissions() because we do not need to fudge permissions anymore for the container's owner since it now owns the objects in question. Acked-by: "Eric W. Biederman" Signed-off-by: Dmitry Torokhov --- fs/proc/proc_sysctl.c | 5 +++++ include/linux/sysctl.h | 4 ++++ net/sysctl_net.c | 29 ++++++++++++++++++++--------- 3 files changed, 29 insertions(+), 9 deletions(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 5e57c3e..28f9085 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -430,6 +430,7 @@ static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, i static struct inode *proc_sys_make_inode(struct super_block *sb, struct ctl_table_header *head, struct ctl_table *table) { + struct ctl_table_root *root = head->root; struct inode *inode; struct proc_inode *ei; @@ -457,6 +458,10 @@ static struct inode *proc_sys_make_inode(struct super_block *sb, if (is_empty_dir(head)) make_empty_dir_inode(inode); } + + if (root->set_ownership) + root->set_ownership(head, table, &inode->i_uid, &inode->i_gid); + out: return inode; } diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index fa7bc29..55bec2f 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -25,6 +25,7 @@ #include #include #include +#include #include /* For the /proc/sys support */ @@ -156,6 +157,9 @@ struct ctl_table_root { struct ctl_table_set default_set; struct ctl_table_set *(*lookup)(struct ctl_table_root *root, struct nsproxy *namespaces); + void (*set_ownership)(struct ctl_table_header *head, + struct ctl_table *table, + kuid_t *uid, kgid_t *gid); int (*permissions)(struct ctl_table_header *head, struct ctl_table *table); }; diff --git a/net/sysctl_net.c b/net/sysctl_net.c index ed98c1f..5bc1a3d 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -42,26 +42,37 @@ static int net_ctl_permissions(struct ctl_table_header *head, struct ctl_table *table) { struct net *net = container_of(head->set, struct net, sysctls); - kuid_t root_uid = make_kuid(net->user_ns, 0); - kgid_t root_gid = make_kgid(net->user_ns, 0); /* Allow network administrator to have same access as root. */ - if (ns_capable(net->user_ns, CAP_NET_ADMIN) || - uid_eq(root_uid, current_euid())) { + if (ns_capable(net->user_ns, CAP_NET_ADMIN)) { int mode = (table->mode >> 6) & 7; return (mode << 6) | (mode << 3) | mode; } - /* Allow netns root group to have the same access as the root group */ - if (in_egroup_p(root_gid)) { - int mode = (table->mode >> 3) & 7; - return (mode << 3) | mode; - } + return table->mode; } +static void net_ctl_set_ownership(struct ctl_table_header *head, + struct ctl_table *table, + kuid_t *uid, kgid_t *gid) +{ + struct net *net = container_of(head->set, struct net, sysctls); + kuid_t ns_root_uid; + kgid_t ns_root_gid; + + ns_root_uid = make_kuid(net->user_ns, 0); + if (uid_valid(ns_root_uid)) + *uid = ns_root_uid; + + ns_root_gid = make_kgid(net->user_ns, 0); + if (gid_valid(ns_root_gid)) + *gid = ns_root_gid; +} + static struct ctl_table_root net_sysctl_root = { .lookup = net_ctl_header_lookup, .permissions = net_ctl_permissions, + .set_ownership = net_ctl_set_ownership, }; static int __net_init sysctl_net_init(struct net *net)