xref: /linux/security/selinux/nlmsgtab.c (revision c34e9ab9a612ee8b18273398ef75c207b01f516d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Netlink message type permission tables, for user generated messages.
4  *
5  * Author: James Morris <jmorris@redhat.com>
6  *
7  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
8  */
9 #include <linux/types.h>
10 #include <linux/kernel.h>
11 #include <linux/netlink.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/if.h>
14 #include <linux/inet_diag.h>
15 #include <linux/xfrm.h>
16 #include <linux/audit.h>
17 #include <linux/sock_diag.h>
18 
19 #include "flask.h"
20 #include "av_permissions.h"
21 #include "security.h"
22 
23 struct nlmsg_perm {
24 	u16 nlmsg_type;
25 	u32 perm;
26 };
27 
28 static const struct nlmsg_perm nlmsg_route_perms[] = {
29 	{ RTM_NEWLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
30 	{ RTM_DELLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
31 	{ RTM_GETLINK, NETLINK_ROUTE_SOCKET__NLMSG_READ },
32 	{ RTM_SETLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
33 	{ RTM_NEWADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
34 	{ RTM_DELADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
35 	{ RTM_GETADDR, NETLINK_ROUTE_SOCKET__NLMSG_READ },
36 	{ RTM_NEWROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
37 	{ RTM_DELROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
38 	{ RTM_GETROUTE, NETLINK_ROUTE_SOCKET__NLMSG_READ },
39 	{ RTM_NEWNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
40 	{ RTM_DELNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
41 	{ RTM_GETNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_READ },
42 	{ RTM_NEWRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
43 	{ RTM_DELRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
44 	{ RTM_GETRULE, NETLINK_ROUTE_SOCKET__NLMSG_READ },
45 	{ RTM_NEWQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
46 	{ RTM_DELQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
47 	{ RTM_GETQDISC, NETLINK_ROUTE_SOCKET__NLMSG_READ },
48 	{ RTM_NEWTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
49 	{ RTM_DELTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
50 	{ RTM_GETTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_READ },
51 	{ RTM_NEWTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
52 	{ RTM_DELTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
53 	{ RTM_GETTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_READ },
54 	{ RTM_NEWACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
55 	{ RTM_DELACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
56 	{ RTM_GETACTION, NETLINK_ROUTE_SOCKET__NLMSG_READ },
57 	{ RTM_NEWPREFIX, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
58 	{ RTM_GETMULTICAST, NETLINK_ROUTE_SOCKET__NLMSG_READ },
59 	{ RTM_GETANYCAST, NETLINK_ROUTE_SOCKET__NLMSG_READ },
60 	{ RTM_GETNEIGHTBL, NETLINK_ROUTE_SOCKET__NLMSG_READ },
61 	{ RTM_SETNEIGHTBL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
62 	{ RTM_NEWADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
63 	{ RTM_DELADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
64 	{ RTM_GETADDRLABEL, NETLINK_ROUTE_SOCKET__NLMSG_READ },
65 	{ RTM_GETDCB, NETLINK_ROUTE_SOCKET__NLMSG_READ },
66 	{ RTM_SETDCB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
67 	{ RTM_NEWNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
68 	{ RTM_DELNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
69 	{ RTM_GETNETCONF, NETLINK_ROUTE_SOCKET__NLMSG_READ },
70 	{ RTM_NEWMDB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
71 	{ RTM_DELMDB, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
72 	{ RTM_GETMDB, NETLINK_ROUTE_SOCKET__NLMSG_READ },
73 	{ RTM_NEWNSID, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
74 	{ RTM_DELNSID, NETLINK_ROUTE_SOCKET__NLMSG_READ },
75 	{ RTM_GETNSID, NETLINK_ROUTE_SOCKET__NLMSG_READ },
76 	{ RTM_NEWSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ },
77 	{ RTM_GETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ },
78 	{ RTM_SETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
79 	{ RTM_NEWCACHEREPORT, NETLINK_ROUTE_SOCKET__NLMSG_READ },
80 	{ RTM_NEWCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
81 	{ RTM_DELCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
82 	{ RTM_GETCHAIN, NETLINK_ROUTE_SOCKET__NLMSG_READ },
83 	{ RTM_NEWNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
84 	{ RTM_DELNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
85 	{ RTM_GETNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_READ },
86 	{ RTM_NEWLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
87 	{ RTM_DELLINKPROP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
88 	{ RTM_NEWVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
89 	{ RTM_DELVLAN, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
90 	{ RTM_GETVLAN, NETLINK_ROUTE_SOCKET__NLMSG_READ },
91 	{ RTM_NEWNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
92 	{ RTM_DELNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
93 	{ RTM_GETNEXTHOPBUCKET, NETLINK_ROUTE_SOCKET__NLMSG_READ },
94 	{ RTM_NEWTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
95 	{ RTM_DELTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
96 	{ RTM_GETTUNNEL, NETLINK_ROUTE_SOCKET__NLMSG_READ },
97 };
98 
99 static const struct nlmsg_perm nlmsg_tcpdiag_perms[] = {
100 	{ TCPDIAG_GETSOCK, NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
101 	{ DCCPDIAG_GETSOCK, NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
102 	{ SOCK_DIAG_BY_FAMILY, NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
103 	{ SOCK_DESTROY, NETLINK_TCPDIAG_SOCKET__NLMSG_WRITE },
104 };
105 
106 static const struct nlmsg_perm nlmsg_xfrm_perms[] = {
107 	{ XFRM_MSG_NEWSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
108 	{ XFRM_MSG_DELSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
109 	{ XFRM_MSG_GETSA, NETLINK_XFRM_SOCKET__NLMSG_READ },
110 	{ XFRM_MSG_NEWPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
111 	{ XFRM_MSG_DELPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
112 	{ XFRM_MSG_GETPOLICY, NETLINK_XFRM_SOCKET__NLMSG_READ },
113 	{ XFRM_MSG_ALLOCSPI, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
114 	{ XFRM_MSG_ACQUIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
115 	{ XFRM_MSG_EXPIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
116 	{ XFRM_MSG_UPDPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
117 	{ XFRM_MSG_UPDSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
118 	{ XFRM_MSG_POLEXPIRE, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
119 	{ XFRM_MSG_FLUSHSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
120 	{ XFRM_MSG_FLUSHPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
121 	{ XFRM_MSG_NEWAE, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
122 	{ XFRM_MSG_GETAE, NETLINK_XFRM_SOCKET__NLMSG_READ },
123 	{ XFRM_MSG_REPORT, NETLINK_XFRM_SOCKET__NLMSG_READ },
124 	{ XFRM_MSG_MIGRATE, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
125 	{ XFRM_MSG_NEWSADINFO, NETLINK_XFRM_SOCKET__NLMSG_READ },
126 	{ XFRM_MSG_GETSADINFO, NETLINK_XFRM_SOCKET__NLMSG_READ },
127 	{ XFRM_MSG_NEWSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
128 	{ XFRM_MSG_GETSPDINFO, NETLINK_XFRM_SOCKET__NLMSG_READ },
129 	{ XFRM_MSG_MAPPING, NETLINK_XFRM_SOCKET__NLMSG_READ },
130 	{ XFRM_MSG_SETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
131 	{ XFRM_MSG_GETDEFAULT, NETLINK_XFRM_SOCKET__NLMSG_READ },
132 };
133 
134 static const struct nlmsg_perm nlmsg_audit_perms[] = {
135 	{ AUDIT_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ },
136 	{ AUDIT_SET, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
137 	{ AUDIT_LIST, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV },
138 	{ AUDIT_ADD, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
139 	{ AUDIT_DEL, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
140 	{ AUDIT_LIST_RULES, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV },
141 	{ AUDIT_ADD_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
142 	{ AUDIT_DEL_RULE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
143 	{ AUDIT_USER, NETLINK_AUDIT_SOCKET__NLMSG_RELAY },
144 	{ AUDIT_SIGNAL_INFO, NETLINK_AUDIT_SOCKET__NLMSG_READ },
145 	{ AUDIT_TRIM, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
146 	{ AUDIT_MAKE_EQUIV, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
147 	{ AUDIT_TTY_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ },
148 	{ AUDIT_TTY_SET, NETLINK_AUDIT_SOCKET__NLMSG_TTY_AUDIT },
149 	{ AUDIT_GET_FEATURE, NETLINK_AUDIT_SOCKET__NLMSG_READ },
150 	{ AUDIT_SET_FEATURE, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
151 };
152 
153 static int nlmsg_perm(u16 nlmsg_type, u32 *perm, const struct nlmsg_perm *tab,
154 		      size_t tabsize)
155 {
156 	unsigned int i;
157 	int err = -EINVAL;
158 
159 	for (i = 0; i < tabsize / sizeof(struct nlmsg_perm); i++)
160 		if (nlmsg_type == tab[i].nlmsg_type) {
161 			*perm = tab[i].perm;
162 			err = 0;
163 			break;
164 		}
165 
166 	return err;
167 }
168 
169 int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
170 {
171 	/* While it is possible to add a similar permission to other netlink
172 	 * classes, note that the extended permission value is matched against
173 	 * the nlmsg_type field. Notably, SECCLASS_NETLINK_GENERIC_SOCKET uses
174 	 * dynamic values for this field, which means that it cannot be added
175 	 * as-is.
176 	 */
177 
178 	switch (sclass) {
179 	case SECCLASS_NETLINK_ROUTE_SOCKET:
180 		/* RTM_MAX always points to RTM_SETxxxx, ie RTM_NEWxxx + 3.
181 		 * If the BUILD_BUG_ON() below fails you must update the
182 		 * structures at the top of this file with the new mappings
183 		 * before updating the BUILD_BUG_ON() macro!
184 		 */
185 		BUILD_BUG_ON(RTM_MAX != (RTM_NEWTUNNEL + 3));
186 
187 		if (selinux_policycap_netlink_xperm()) {
188 			*perm = NETLINK_ROUTE_SOCKET__NLMSG;
189 			return 0;
190 		}
191 		return nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
192 				  sizeof(nlmsg_route_perms));
193 		break;
194 	case SECCLASS_NETLINK_TCPDIAG_SOCKET:
195 		if (selinux_policycap_netlink_xperm()) {
196 			*perm = NETLINK_TCPDIAG_SOCKET__NLMSG;
197 			return 0;
198 		}
199 		return nlmsg_perm(nlmsg_type, perm, nlmsg_tcpdiag_perms,
200 				  sizeof(nlmsg_tcpdiag_perms));
201 		break;
202 	case SECCLASS_NETLINK_XFRM_SOCKET:
203 		/* If the BUILD_BUG_ON() below fails you must update the
204 		 * structures at the top of this file with the new mappings
205 		 * before updating the BUILD_BUG_ON() macro!
206 		 */
207 		BUILD_BUG_ON(XFRM_MSG_MAX != XFRM_MSG_GETDEFAULT);
208 
209 		if (selinux_policycap_netlink_xperm()) {
210 			*perm = NETLINK_XFRM_SOCKET__NLMSG;
211 			return 0;
212 		}
213 		return nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms,
214 				  sizeof(nlmsg_xfrm_perms));
215 		break;
216 	case SECCLASS_NETLINK_AUDIT_SOCKET:
217 		if (selinux_policycap_netlink_xperm()) {
218 			*perm = NETLINK_AUDIT_SOCKET__NLMSG;
219 			return 0;
220 		} else if ((nlmsg_type >= AUDIT_FIRST_USER_MSG &&
221 			    nlmsg_type <= AUDIT_LAST_USER_MSG) ||
222 			   (nlmsg_type >= AUDIT_FIRST_USER_MSG2 &&
223 			    nlmsg_type <= AUDIT_LAST_USER_MSG2)) {
224 			*perm = NETLINK_AUDIT_SOCKET__NLMSG_RELAY;
225 			return 0;
226 		}
227 		return nlmsg_perm(nlmsg_type, perm, nlmsg_audit_perms,
228 				  sizeof(nlmsg_audit_perms));
229 		break;
230 	}
231 
232 	/* No messaging from userspace, or class unknown/unhandled */
233 	return -ENOENT;
234 }
235