Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754333AbZL0BEx (ORCPT ); Sat, 26 Dec 2009 20:04:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754270AbZL0BEt (ORCPT ); Sat, 26 Dec 2009 20:04:49 -0500 Received: from lists.laptop.org ([18.85.2.145]:45135 "EHLO mail.laptop.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754230AbZL0BEp (ORCPT ); Sat, 26 Dec 2009 20:04:45 -0500 Date: Sat, 26 Dec 2009 20:06:50 -0500 From: Michael Stone To: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org, linux-security-module@vger.kernel.org, Andi Kleen , David Lang , Oliver Hartkopp , Alan Cox , Herbert Xu , Valdis Kletnieks , Bryan Donlan , Evgeniy Polyakov , "C. Scott Ananian" , James Morris , "Eric W. Biederman" , Bernie Innocenti , Mark Seaborn , Randy Dunlap , =?iso-8859-1?Q?Am=E9rico?= Wang , Tetsuo Handa , Samir Bellabes , Casey Schaufler , "Serge E. Hallyn" , Pavel Machek , Michael Stone Subject: [PATCH 2/3] Security: Implement disablenetwork semantics. (v4) Message-ID: <20091227010650.GA12190@heat> References: <20091227010441.GA12077@heat> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091227010441.GA12077@heat> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7521 Lines: 259 Implement security_* hooks for socket_create, socket_bind, socket_connect, socket_sendmsg, and ptrace_access_check which return -EPERM when called from a process with networking restrictions. Exempt AF_UNIX sockets. Signed-off-by: Michael Stone --- include/linux/disablenetwork.h | 22 +++++++++++ security/Makefile | 1 + security/disablenetwork.c | 73 ++++++++++++++++++++++++++++++++++++++ security/security.c | 76 +++++++++++++++++++++++++++++++++++++--- 4 files changed, 167 insertions(+), 5 deletions(-) create mode 100644 include/linux/disablenetwork.h create mode 100644 security/disablenetwork.c diff --git a/include/linux/disablenetwork.h b/include/linux/disablenetwork.h new file mode 100644 index 0000000..8a7bcc2 --- /dev/null +++ b/include/linux/disablenetwork.h @@ -0,0 +1,22 @@ +#ifndef __LINUX_DISABLENETWORK_H +#define __LINUX_DISABLENETWORK_H + +#ifdef CONFIG_SECURITY_DISABLENETWORK + +int disablenetwork_security_socket_create(int family, int type, + int protocol, int kern); +int disablenetwork_security_socket_bind(struct socket *sock, + struct sockaddr *address, + int addrlen); +int disablenetwork_security_socket_connect(struct socket *sock, + struct sockaddr *address, + int addrlen); +int disablenetwork_security_socket_sendmsg(struct socket *sock, + struct msghdr *msg, + int size); +int disablenetwork_security_ptrace_access_check(struct task_struct *child, + unsigned int mode); + +#endif /* CONFIG_SECURITY_DISABLENETWORK */ + +#endif /* ! __LINUX_DISABLENETWORK_H */ diff --git a/security/Makefile b/security/Makefile index da20a19..2f23b60 100644 --- a/security/Makefile +++ b/security/Makefile @@ -20,6 +20,7 @@ obj-$(CONFIG_SECURITY_SMACK) += smack/built-in.o obj-$(CONFIG_AUDIT) += lsm_audit.o obj-$(CONFIG_SECURITY_TOMOYO) += tomoyo/built-in.o obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o +obj-$(CONFIG_SECURITY_DISABLENETWORK) += disablenetwork.o # Object integrity file lists subdir-$(CONFIG_IMA) += integrity/ima diff --git a/security/disablenetwork.c b/security/disablenetwork.c new file mode 100644 index 0000000..f45ddfc --- /dev/null +++ b/security/disablenetwork.c @@ -0,0 +1,73 @@ +/* + * disablenetwork security hooks. + * + * Copyright (C) 2008-2009 Michael Stone + * + * Implements the disablenetwork discretionary access control logic underlying + * the prctl(PRCTL_SET_NETWORK, PR_NETWORK_OFF) interface. + * + * See Documentation/disablenetwork.txt for more information. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + */ + +#include +#include +#include +#include +#include + +static inline int maybe_allow(void) +{ + if (current->network) + return -EPERM; + return 0; +} + +int disablenetwork_security_socket_create(int family, int type, + int protocol, int kern) +{ + if (family == AF_UNIX) + return 0; + return maybe_allow(); +} + +int disablenetwork_security_socket_bind(struct socket * sock, + struct sockaddr * address, + int addrlen) +{ + if (address->sa_family == AF_UNIX) + return 0; + return maybe_allow(); +} + +int disablenetwork_security_socket_connect(struct socket * sock, + struct sockaddr * address, + int addrlen) +{ + if (address->sa_family == AF_UNIX) + return 0; + return maybe_allow(); +} + +int disablenetwork_security_socket_sendmsg(struct socket * sock, + struct msghdr * msg, int size) +{ + if (sock->sk->sk_family != PF_UNIX && + current->network && + (msg->msg_name != NULL || msg->msg_namelen != 0)) + return -EPERM; + return 0; +} + +int disablenetwork_security_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + /* does current have networking restrictions not shared by child? */ + if (current->network & ~child->network) + return -EPERM; + return 0; +} diff --git a/security/security.c b/security/security.c index 24e060b..40ac615 100644 --- a/security/security.c +++ b/security/security.c @@ -17,6 +17,7 @@ #include #include #include +#include /* Boot-time LSM user choice */ static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1] = @@ -130,7 +131,20 @@ int register_security(struct security_operations *ops) int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { - return security_ops->ptrace_access_check(child, mode); + int ret = 0; + + ret = security_ops->ptrace_access_check(child, mode); + if (ret) + goto out; + +#ifdef CONFIG_SECURITY_DISABLENETWORK + ret = disablenetwork_security_ptrace_access_check(child, mode); + if (ret) + goto out; +#endif + +out: + return ret; } int security_ptrace_traceme(struct task_struct *parent) @@ -1054,7 +1068,20 @@ EXPORT_SYMBOL(security_unix_may_send); int security_socket_create(int family, int type, int protocol, int kern) { - return security_ops->socket_create(family, type, protocol, kern); + int ret = 0; + + ret = security_ops->socket_create(family, type, protocol, kern); + if (ret) + goto out; + +#ifdef CONFIG_SECURITY_DISABLENETWORK + ret = disablenetwork_security_socket_create(family, type, protocol, kern); + if (ret) + goto out; +#endif + +out: + return ret; } int security_socket_post_create(struct socket *sock, int family, @@ -1066,12 +1093,38 @@ int security_socket_post_create(struct socket *sock, int family, int security_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) { - return security_ops->socket_bind(sock, address, addrlen); + int ret = 0; + + ret = security_ops->socket_bind(sock, address, addrlen); + if (ret) + goto out; + +#ifdef CONFIG_SECURITY_DISABLENETWORK + ret = disablenetwork_security_socket_bind(sock, address, addrlen); + if (ret) + goto out; +#endif + +out: + return ret; } int security_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) { - return security_ops->socket_connect(sock, address, addrlen); + int ret = 0; + + ret = security_ops->socket_connect(sock, address, addrlen); + if (ret) + goto out; + +#ifdef CONFIG_SECURITY_DISABLENETWORK + ret = disablenetwork_security_socket_connect(sock, address, addrlen); + if (ret) + goto out; +#endif + +out: + return ret; } int security_socket_listen(struct socket *sock, int backlog) @@ -1086,7 +1139,20 @@ int security_socket_accept(struct socket *sock, struct socket *newsock) int security_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size) { - return security_ops->socket_sendmsg(sock, msg, size); + int ret = 0; + + ret = security_ops->socket_sendmsg(sock, msg, size); + if (ret) + goto out; + +#ifdef CONFIG_SECURITY_DISABLENETWORK + ret = disablenetwork_security_socket_sendmsg(sock, msg, size); + if (ret) + goto out; +#endif + +out: + return ret; } int security_socket_recvmsg(struct socket *sock, struct msghdr *msg, -- 1.6.6.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/