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
20const char *const audit_mode_names[] = {
21	"normal",
22	"quiet_denied",
23	"quiet",
24	"noquiet",
25	"all"
26};
27
28static 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 */
55static 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 */
105void 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 */
123int 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
161struct aa_audit_rule {
162	struct aa_label *label;
163};
164
165void 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
176int 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
207int 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
223int 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