From ed6d76e4c32de0c2ad5f1d572b948ef49e465176 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 28 Aug 2009 18:12:49 -0400 Subject: [PATCH] selinux: Support for the new TUN LSM hooks Add support for the new TUN LSM hooks: security_tun_dev_create(), security_tun_dev_post_create() and security_tun_dev_attach(). This includes the addition of a new object class, tun_socket, which represents the socks associated with TUN devices. The _tun_dev_create() and _tun_dev_post_create() hooks are fairly similar to the standard socket functions but _tun_dev_attach() is a bit special. The _tun_dev_attach() is unique because it involves a domain attaching to an existing TUN device and its associated tun_socket object, an operation which does not exist with standard sockets and most closely resembles a relabel operation. Signed-off-by: Paul Moore Acked-by: Eric Paris Signed-off-by: James Morris --- security/selinux/hooks.c | 60 +++++++++++++++++++++- security/selinux/include/av_inherit.h | 1 + security/selinux/include/av_permissions.h | 22 ++++++++ security/selinux/include/class_to_string.h | 1 + security/selinux/include/flask.h | 1 + 5 files changed, 83 insertions(+), 2 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ac79f9ef2da8..27b4c5527358 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -13,8 +13,8 @@ * Eric Paris * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. * - * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. - * Paul Moore + * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. + * Paul Moore * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. * Yuichi Nakamura * @@ -4325,6 +4325,59 @@ static void selinux_req_classify_flow(const struct request_sock *req, fl->secid = req->secid; } +static int selinux_tun_dev_create(void) +{ + u32 sid = current_sid(); + + /* we aren't taking into account the "sockcreate" SID since the socket + * that is being created here is not a socket in the traditional sense, + * instead it is a private sock, accessible only to the kernel, and + * representing a wide range of network traffic spanning multiple + * connections unlike traditional sockets - check the TUN driver to + * get a better understanding of why this socket is special */ + + return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, + NULL); +} + +static void selinux_tun_dev_post_create(struct sock *sk) +{ + struct sk_security_struct *sksec = sk->sk_security; + + /* we don't currently perform any NetLabel based labeling here and it + * isn't clear that we would want to do so anyway; while we could apply + * labeling without the support of the TUN user the resulting labeled + * traffic from the other end of the connection would almost certainly + * cause confusion to the TUN user that had no idea network labeling + * protocols were being used */ + + /* see the comments in selinux_tun_dev_create() about why we don't use + * the sockcreate SID here */ + + sksec->sid = current_sid(); + sksec->sclass = SECCLASS_TUN_SOCKET; +} + +static int selinux_tun_dev_attach(struct sock *sk) +{ + struct sk_security_struct *sksec = sk->sk_security; + u32 sid = current_sid(); + int err; + + err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__RELABELFROM, NULL); + if (err) + return err; + err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, + TUN_SOCKET__RELABELTO, NULL); + if (err) + return err; + + sksec->sid = sid; + + return 0; +} + static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) { int err = 0; @@ -5494,6 +5547,9 @@ static struct security_operations selinux_ops = { .inet_csk_clone = selinux_inet_csk_clone, .inet_conn_established = selinux_inet_conn_established, .req_classify_flow = selinux_req_classify_flow, + .tun_dev_create = selinux_tun_dev_create, + .tun_dev_post_create = selinux_tun_dev_post_create, + .tun_dev_attach = selinux_tun_dev_attach, #ifdef CONFIG_SECURITY_NETWORK_XFRM .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, diff --git a/security/selinux/include/av_inherit.h b/security/selinux/include/av_inherit.h index 8377a4ba3b95..abedcd704dae 100644 --- a/security/selinux/include/av_inherit.h +++ b/security/selinux/include/av_inherit.h @@ -15,6 +15,7 @@ S_(SECCLASS_KEY_SOCKET, socket, 0x00400000UL) S_(SECCLASS_UNIX_STREAM_SOCKET, socket, 0x00400000UL) S_(SECCLASS_UNIX_DGRAM_SOCKET, socket, 0x00400000UL) + S_(SECCLASS_TUN_SOCKET, socket, 0x00400000UL) S_(SECCLASS_IPC, ipc, 0x00000200UL) S_(SECCLASS_SEM, ipc, 0x00000200UL) S_(SECCLASS_MSGQ, ipc, 0x00000200UL) diff --git a/security/selinux/include/av_permissions.h b/security/selinux/include/av_permissions.h index 21c722669902..0546d616ccac 100644 --- a/security/selinux/include/av_permissions.h +++ b/security/selinux/include/av_permissions.h @@ -423,6 +423,28 @@ #define UNIX_DGRAM_SOCKET__RECV_MSG 0x00080000UL #define UNIX_DGRAM_SOCKET__SEND_MSG 0x00100000UL #define UNIX_DGRAM_SOCKET__NAME_BIND 0x00200000UL +#define TUN_SOCKET__IOCTL 0x00000001UL +#define TUN_SOCKET__READ 0x00000002UL +#define TUN_SOCKET__WRITE 0x00000004UL +#define TUN_SOCKET__CREATE 0x00000008UL +#define TUN_SOCKET__GETATTR 0x00000010UL +#define TUN_SOCKET__SETATTR 0x00000020UL +#define TUN_SOCKET__LOCK 0x00000040UL +#define TUN_SOCKET__RELABELFROM 0x00000080UL +#define TUN_SOCKET__RELABELTO 0x00000100UL +#define TUN_SOCKET__APPEND 0x00000200UL +#define TUN_SOCKET__BIND 0x00000400UL +#define TUN_SOCKET__CONNECT 0x00000800UL +#define TUN_SOCKET__LISTEN 0x00001000UL +#define TUN_SOCKET__ACCEPT 0x00002000UL +#define TUN_SOCKET__GETOPT 0x00004000UL +#define TUN_SOCKET__SETOPT 0x00008000UL +#define TUN_SOCKET__SHUTDOWN 0x00010000UL +#define TUN_SOCKET__RECVFROM 0x00020000UL +#define TUN_SOCKET__SENDTO 0x00040000UL +#define TUN_SOCKET__RECV_MSG 0x00080000UL +#define TUN_SOCKET__SEND_MSG 0x00100000UL +#define TUN_SOCKET__NAME_BIND 0x00200000UL #define PROCESS__FORK 0x00000001UL #define PROCESS__TRANSITION 0x00000002UL #define PROCESS__SIGCHLD 0x00000004UL diff --git a/security/selinux/include/class_to_string.h b/security/selinux/include/class_to_string.h index 21ec786611d4..7ab9299bfb6b 100644 --- a/security/selinux/include/class_to_string.h +++ b/security/selinux/include/class_to_string.h @@ -77,3 +77,4 @@ S_(NULL) S_(NULL) S_("kernel_service") + S_("tun_socket") diff --git a/security/selinux/include/flask.h b/security/selinux/include/flask.h index 882f27d66fac..f248500a1e3c 100644 --- a/security/selinux/include/flask.h +++ b/security/selinux/include/flask.h @@ -53,6 +53,7 @@ #define SECCLASS_PEER 68 #define SECCLASS_CAPABILITY2 69 #define SECCLASS_KERNEL_SERVICE 74 +#define SECCLASS_TUN_SOCKET 75 /* * Security identifier indices for initial entities -- 2.20.1