selinux: support distinctions among all network address families

Extend SELinux to support distinctions among all network address families
implemented by the kernel by defining new socket security classes
and mapping to them. Otherwise, many sockets are mapped to the generic
socket class and are indistinguishable in policy.  This has come up
previously with regard to selectively allowing access to bluetooth sockets,
and more recently with regard to selectively allowing access to AF_ALG
sockets.  Guido Trentalancia submitted a patch that took a similar approach
to add only support for distinguishing AF_ALG sockets, but this generalizes
his approach to handle all address families implemented by the kernel.
Socket security classes are also added for ICMP and SCTP sockets.
Socket security classes were not defined for AF_* values that are reserved
but unimplemented in the kernel, e.g. AF_NETBEUI, AF_SECURITY, AF_ASH,
AF_ECONET, AF_SNA, AF_WANPIPE.

Backward compatibility is provided by only enabling the finer-grained
socket classes if a new policy capability is set in the policy; older
policies will behave as before.  The legacy redhat1 policy capability
that was only ever used in testing within Fedora for ptrace_child
is reclaimed for this purpose; as far as I can tell, this policy
capability is not enabled in any supported distro policy.

Add a pair of conditional compilation guards to detect when new AF_* values
are added so that we can update SELinux accordingly rather than having to
belatedly update it long after new address families are introduced.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>

2 files changed, 70 insertions, 1 deletions

diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 13ae49b0baa0..0dfd26d0b8d8 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -171,5 +171,73 @@ struct security_class_mapping secclass_map[] = {
 	  { COMMON_CAP_PERMS, NULL } },
 	{ "cap2_userns",
 	  { COMMON_CAP2_PERMS, NULL } },
+	{ "sctp_socket",
+	  { COMMON_SOCK_PERMS,
+	    "node_bind", NULL } },
+	{ "icmp_socket",
+	  { COMMON_SOCK_PERMS,
+	    "node_bind", NULL } },
+	{ "ax25_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "ipx_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "netrom_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "bridge_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "atmpvc_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "x25_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "rose_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "decnet_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "atmsvc_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "rds_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "irda_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "pppox_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "llc_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "ib_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "mpls_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "can_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "tipc_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "bluetooth_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "iucv_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "rxrpc_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "isdn_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "phonet_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "ieee802154_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "caif_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "alg_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "nfc_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "vsock_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "kcm_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
+	{ "qipcrtr_socket",
+	  { COMMON_SOCK_PERMS, NULL } },
 	{ NULL }
   };
+
+#if PF_MAX > 43
+#error New address family defined, please update secclass_map.
+#endif
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index 308a286c6cbe..beaa14b8b6cf 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -69,7 +69,7 @@ extern int selinux_enabled;
 enum {
 	POLICYDB_CAPABILITY_NETPEER,
 	POLICYDB_CAPABILITY_OPENPERM,
-	POLICYDB_CAPABILITY_REDHAT1,
+	POLICYDB_CAPABILITY_EXTSOCKCLASS,
 	POLICYDB_CAPABILITY_ALWAYSNETWORK,
 	__POLICYDB_CAPABILITY_MAX
 };
@@ -77,6 +77,7 @@ enum {
 
 extern int selinux_policycap_netpeer;
 extern int selinux_policycap_openperm;
+extern int selinux_policycap_extsockclass;
 extern int selinux_policycap_alwaysnetwork;
 
 /*