1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AppArmor security module
4 *
5 * This file contains AppArmor auditing functions
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 */
10
11 #include <linux/audit.h>
12 #include <linux/socket.h>
13
14 #include "include/apparmor.h"
15 #include "include/audit.h"
16 #include "include/policy.h"
17 #include "include/policy_ns.h"
18 #include "include/secid.h"
19
20 const char *const audit_mode_names[] = {
21 "normal",
22 "quiet_denied",
23 "quiet",
24 "noquiet",
25 "all"
26 };
27
28 static const char *const aa_audit_type[] = {
29 "AUDIT",
30 "ALLOWED",
31 "DENIED",
32 "HINT",
33 "STATUS",
34 "ERROR",
35 "KILLED",
36 "AUTO"
37 };
38
39 /*
40 * Currently AppArmor auditing is fed straight into the audit framework.
41 *
42 * TODO:
43 * netlink interface for complain mode
44 * user auditing, - send user auditing to netlink interface
45 * system control of whether user audit messages go to system log
46 */
47
48 /**
49 * audit_base - core AppArmor function.
50 * @ab: audit buffer to fill (NOT NULL)
51 * @ca: audit structure containing data to audit (NOT NULL)
52 *
53 * Record common AppArmor audit data from @sa
54 */
audit_pre(struct audit_buffer * ab,void * ca)55 static void audit_pre(struct audit_buffer *ab, void *ca)
56 {
57 struct common_audit_data *sa = ca;
58
59 if (aa_g_audit_header) {
60 audit_log_format(ab, "apparmor=");
61 audit_log_string(ab, aa_audit_type[aad(sa)->type]);
62 }
63
64 if (aad(sa)->op) {
65 audit_log_format(ab, " operation=");
66 audit_log_string(ab, aad(sa)->op);
67 }
68
69 if (aad(sa)->info) {
70 audit_log_format(ab, " info=");
71 audit_log_string(ab, aad(sa)->info);
72 if (aad(sa)->error)
73 audit_log_format(ab, " error=%d", aad(sa)->error);
74 }
75
76 if (aad(sa)->label) {
77 struct aa_label *label = aad(sa)->label;
78
79 if (label_isprofile(label)) {
80 struct aa_profile *profile = labels_profile(label);
81
82 if (profile->ns != root_ns) {
83 audit_log_format(ab, " namespace=");
84 audit_log_untrustedstring(ab,
85 profile->ns->base.hname);
86 }
87 audit_log_format(ab, " profile=");
88 audit_log_untrustedstring(ab, profile->base.hname);
89 } else {
90 audit_log_format(ab, " label=");
91 aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS,
92 GFP_ATOMIC);
93 }
94 }
95
96 if (aad(sa)->name) {
97 audit_log_format(ab, " name=");
98 audit_log_untrustedstring(ab, aad(sa)->name);
99 }
100 }
101
102 /**
103 * aa_audit_msg - Log a message to the audit subsystem
104 * @sa: audit event structure (NOT NULL)
105 * @cb: optional callback fn for type specific fields (MAYBE NULL)
106 */
aa_audit_msg(int type,struct common_audit_data * sa,void (* cb)(struct audit_buffer *,void *))107 void aa_audit_msg(int type, struct common_audit_data *sa,
108 void (*cb) (struct audit_buffer *, void *))
109 {
110 aad(sa)->type = type;
111 common_lsm_audit(sa, audit_pre, cb);
112 }
113
114 /**
115 * aa_audit - Log a profile based audit event to the audit subsystem
116 * @type: audit type for the message
117 * @profile: profile to check against (NOT NULL)
118 * @sa: audit event (NOT NULL)
119 * @cb: optional callback fn for type specific fields (MAYBE NULL)
120 *
121 * Handle default message switching based off of audit mode flags
122 *
123 * Returns: error on failure
124 */
aa_audit(int type,struct aa_profile * profile,struct common_audit_data * sa,void (* cb)(struct audit_buffer *,void *))125 int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa,
126 void (*cb) (struct audit_buffer *, void *))
127 {
128 AA_BUG(!profile);
129
130 if (type == AUDIT_APPARMOR_AUTO) {
131 if (likely(!aad(sa)->error)) {
132 if (AUDIT_MODE(profile) != AUDIT_ALL)
133 return 0;
134 type = AUDIT_APPARMOR_AUDIT;
135 } else if (COMPLAIN_MODE(profile))
136 type = AUDIT_APPARMOR_ALLOWED;
137 else
138 type = AUDIT_APPARMOR_DENIED;
139 }
140 if (AUDIT_MODE(profile) == AUDIT_QUIET ||
141 (type == AUDIT_APPARMOR_DENIED &&
142 AUDIT_MODE(profile) == AUDIT_QUIET))
143 return aad(sa)->error;
144
145 if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
146 type = AUDIT_APPARMOR_KILL;
147
148 aad(sa)->label = &profile->label;
149
150 aa_audit_msg(type, sa, cb);
151
152 if (aad(sa)->type == AUDIT_APPARMOR_KILL)
153 (void)send_sig_info(SIGKILL, NULL,
154 sa->type == LSM_AUDIT_DATA_TASK && sa->u.tsk ?
155 sa->u.tsk : current);
156
157 if (aad(sa)->type == AUDIT_APPARMOR_ALLOWED)
158 return complain_error(aad(sa)->error);
159
160 return aad(sa)->error;
161 }
162
163 struct aa_audit_rule {
164 struct aa_label *label;
165 };
166
aa_audit_rule_free(void * vrule)167 void aa_audit_rule_free(void *vrule)
168 {
169 struct aa_audit_rule *rule = vrule;
170
171 if (rule) {
172 if (!IS_ERR(rule->label))
173 aa_put_label(rule->label);
174 kfree(rule);
175 }
176 }
177
aa_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)178 int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
179 {
180 struct aa_audit_rule *rule;
181
182 switch (field) {
183 case AUDIT_SUBJ_ROLE:
184 if (op != Audit_equal && op != Audit_not_equal)
185 return -EINVAL;
186 break;
187 default:
188 return -EINVAL;
189 }
190
191 rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
192
193 if (!rule)
194 return -ENOMEM;
195
196 /* Currently rules are treated as coming from the root ns */
197 rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
198 GFP_KERNEL, true, false);
199 if (IS_ERR(rule->label)) {
200 aa_audit_rule_free(rule);
201 return PTR_ERR(rule->label);
202 }
203
204 *vrule = rule;
205 return 0;
206 }
207
aa_audit_rule_known(struct audit_krule * rule)208 int aa_audit_rule_known(struct audit_krule *rule)
209 {
210 int i;
211
212 for (i = 0; i < rule->field_count; i++) {
213 struct audit_field *f = &rule->fields[i];
214
215 switch (f->type) {
216 case AUDIT_SUBJ_ROLE:
217 return 1;
218 }
219 }
220
221 return 0;
222 }
223
aa_audit_rule_match(u32 sid,u32 field,u32 op,void * vrule)224 int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
225 {
226 struct aa_audit_rule *rule = vrule;
227 struct aa_label *label;
228 int found = 0;
229
230 label = aa_secid_to_label(sid);
231
232 if (!label)
233 return -ENOENT;
234
235 if (aa_label_is_subset(label, rule->label))
236 found = 1;
237
238 switch (field) {
239 case AUDIT_SUBJ_ROLE:
240 switch (op) {
241 case Audit_equal:
242 return found;
243 case Audit_not_equal:
244 return !found;
245 }
246 }
247 return 0;
248 }
249