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=\"%s\"",
61 aa_audit_type[aad(sa)->type]);
62 }
63
64 if (aad(sa)->op) {
65 audit_log_format(ab, " operation=\"%s\"", aad(sa)->op);
66 }
67
68 if (aad(sa)->info) {
69 audit_log_format(ab, " info=\"%s\"", aad(sa)->info);
70 if (aad(sa)->error)
71 audit_log_format(ab, " error=%d", aad(sa)->error);
72 }
73
74 if (aad(sa)->label) {
75 struct aa_label *label = aad(sa)->label;
76
77 if (label_isprofile(label)) {
78 struct aa_profile *profile = labels_profile(label);
79
80 if (profile->ns != root_ns) {
81 audit_log_format(ab, " namespace=");
82 audit_log_untrustedstring(ab,
83 profile->ns->base.hname);
84 }
85 audit_log_format(ab, " profile=");
86 audit_log_untrustedstring(ab, profile->base.hname);
87 } else {
88 audit_log_format(ab, " label=");
89 aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS,
90 GFP_ATOMIC);
91 }
92 }
93
94 if (aad(sa)->name) {
95 audit_log_format(ab, " name=");
96 audit_log_untrustedstring(ab, aad(sa)->name);
97 }
98 }
99
100 /**
101 * aa_audit_msg - Log a message to the audit subsystem
102 * @sa: audit event structure (NOT NULL)
103 * @cb: optional callback fn for type specific fields (MAYBE NULL)
104 */
aa_audit_msg(int type,struct common_audit_data * sa,void (* cb)(struct audit_buffer *,void *))105 void aa_audit_msg(int type, struct common_audit_data *sa,
106 void (*cb) (struct audit_buffer *, void *))
107 {
108 aad(sa)->type = type;
109 common_lsm_audit(sa, audit_pre, cb);
110 }
111
112 /**
113 * aa_audit - Log a profile based audit event to the audit subsystem
114 * @type: audit type for the message
115 * @profile: profile to check against (NOT NULL)
116 * @sa: audit event (NOT NULL)
117 * @cb: optional callback fn for type specific fields (MAYBE NULL)
118 *
119 * Handle default message switching based off of audit mode flags
120 *
121 * Returns: error on failure
122 */
aa_audit(int type,struct aa_profile * profile,struct common_audit_data * sa,void (* cb)(struct audit_buffer *,void *))123 int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa,
124 void (*cb) (struct audit_buffer *, void *))
125 {
126 AA_BUG(!profile);
127
128 if (type == AUDIT_APPARMOR_AUTO) {
129 if (likely(!aad(sa)->error)) {
130 if (AUDIT_MODE(profile) != AUDIT_ALL)
131 return 0;
132 type = AUDIT_APPARMOR_AUDIT;
133 } else if (COMPLAIN_MODE(profile))
134 type = AUDIT_APPARMOR_ALLOWED;
135 else
136 type = AUDIT_APPARMOR_DENIED;
137 }
138 if (AUDIT_MODE(profile) == AUDIT_QUIET ||
139 (type == AUDIT_APPARMOR_DENIED &&
140 AUDIT_MODE(profile) == AUDIT_QUIET_DENIED))
141 return aad(sa)->error;
142
143 if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
144 type = AUDIT_APPARMOR_KILL;
145
146 aad(sa)->label = &profile->label;
147
148 aa_audit_msg(type, sa, cb);
149
150 if (aad(sa)->type == AUDIT_APPARMOR_KILL)
151 (void)send_sig_info(SIGKILL, NULL,
152 sa->type == LSM_AUDIT_DATA_TASK && sa->u.tsk ?
153 sa->u.tsk : current);
154
155 if (aad(sa)->type == AUDIT_APPARMOR_ALLOWED)
156 return complain_error(aad(sa)->error);
157
158 return aad(sa)->error;
159 }
160
161 struct aa_audit_rule {
162 struct aa_label *label;
163 };
164
aa_audit_rule_free(void * vrule)165 void aa_audit_rule_free(void *vrule)
166 {
167 struct aa_audit_rule *rule = vrule;
168
169 if (rule) {
170 if (!IS_ERR(rule->label))
171 aa_put_label(rule->label);
172 kfree(rule);
173 }
174 }
175
aa_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)176 int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
177 {
178 struct aa_audit_rule *rule;
179
180 switch (field) {
181 case AUDIT_SUBJ_ROLE:
182 if (op != Audit_equal && op != Audit_not_equal)
183 return -EINVAL;
184 break;
185 default:
186 return -EINVAL;
187 }
188
189 rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
190
191 if (!rule)
192 return -ENOMEM;
193
194 /* Currently rules are treated as coming from the root ns */
195 rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
196 GFP_KERNEL, true, false);
197 if (IS_ERR(rule->label)) {
198 int err = PTR_ERR(rule->label);
199 aa_audit_rule_free(rule);
200 return err;
201 }
202
203 *vrule = rule;
204 return 0;
205 }
206
aa_audit_rule_known(struct audit_krule * rule)207 int aa_audit_rule_known(struct audit_krule *rule)
208 {
209 int i;
210
211 for (i = 0; i < rule->field_count; i++) {
212 struct audit_field *f = &rule->fields[i];
213
214 switch (f->type) {
215 case AUDIT_SUBJ_ROLE:
216 return 1;
217 }
218 }
219
220 return 0;
221 }
222
aa_audit_rule_match(u32 sid,u32 field,u32 op,void * vrule)223 int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule)
224 {
225 struct aa_audit_rule *rule = vrule;
226 struct aa_label *label;
227 int found = 0;
228
229 label = aa_secid_to_label(sid);
230
231 if (!label)
232 return -ENOENT;
233
234 if (aa_label_is_subset(label, rule->label))
235 found = 1;
236
237 switch (field) {
238 case AUDIT_SUBJ_ROLE:
239 switch (op) {
240 case Audit_equal:
241 return found;
242 case Audit_not_equal:
243 return !found;
244 }
245 }
246 return 0;
247 }
248