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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor ipc mediation
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2017 Canonical Ltd.
9 */
10
11#include <linux/gfp.h>
12#include <linux/ptrace.h>
13
14#include "include/audit.h"
15#include "include/capability.h"
16#include "include/cred.h"
17#include "include/policy.h"
18#include "include/ipc.h"
19#include "include/sig_names.h"
20
21/**
22 * audit_ptrace_mask - convert mask to permission string
23 * @buffer: buffer to write string to (NOT NULL)
24 * @mask: permission mask to convert
25 */
26static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
27{
28 switch (mask) {
29 case MAY_READ:
30 audit_log_string(ab, "read");
31 break;
32 case MAY_WRITE:
33 audit_log_string(ab, "trace");
34 break;
35 case AA_MAY_BE_READ:
36 audit_log_string(ab, "readby");
37 break;
38 case AA_MAY_BE_TRACED:
39 audit_log_string(ab, "tracedby");
40 break;
41 }
42}
43
44/* call back to audit ptrace fields */
45static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
46{
47 struct common_audit_data *sa = va;
48
49 if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
50 audit_log_format(ab, " requested_mask=");
51 audit_ptrace_mask(ab, aad(sa)->request);
52
53 if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
54 audit_log_format(ab, " denied_mask=");
55 audit_ptrace_mask(ab, aad(sa)->denied);
56 }
57 }
58 audit_log_format(ab, " peer=");
59 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
60 FLAGS_NONE, GFP_ATOMIC);
61}
62
63/* assumes check for PROFILE_MEDIATES is already done */
64/* TODO: conditionals */
65static int profile_ptrace_perm(struct aa_profile *profile,
66 struct aa_label *peer, u32 request,
67 struct common_audit_data *sa)
68{
69 struct aa_perms perms = { };
70
71 aad(sa)->peer = peer;
72 aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
73 &perms);
74 aa_apply_modes_to_perms(profile, &perms);
75 return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
76}
77
78static int profile_tracee_perm(struct aa_profile *tracee,
79 struct aa_label *tracer, u32 request,
80 struct common_audit_data *sa)
81{
82 if (profile_unconfined(tracee) || unconfined(tracer) ||
83 !PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
84 return 0;
85
86 return profile_ptrace_perm(tracee, tracer, request, sa);
87}
88
89static int profile_tracer_perm(struct aa_profile *tracer,
90 struct aa_label *tracee, u32 request,
91 struct common_audit_data *sa)
92{
93 if (profile_unconfined(tracer))
94 return 0;
95
96 if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
97 return profile_ptrace_perm(tracer, tracee, request, sa);
98
99 /* profile uses the old style capability check for ptrace */
100 if (&tracer->label == tracee)
101 return 0;
102
103 aad(sa)->label = &tracer->label;
104 aad(sa)->peer = tracee;
105 aad(sa)->request = 0;
106 aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE,
107 CAP_OPT_NONE);
108
109 return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
110}
111
112/**
113 * aa_may_ptrace - test if tracer task can trace the tracee
114 * @tracer: label of the task doing the tracing (NOT NULL)
115 * @tracee: task label to be traced
116 * @request: permission request
117 *
118 * Returns: %0 else error code if permission denied or error
119 */
120int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
121 u32 request)
122{
123 struct aa_profile *profile;
124 u32 xrequest = request << PTRACE_PERM_SHIFT;
125 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
126
127 return xcheck_labels(tracer, tracee, profile,
128 profile_tracer_perm(profile, tracee, request, &sa),
129 profile_tracee_perm(profile, tracer, xrequest, &sa));
130}
131
132
133static inline int map_signal_num(int sig)
134{
135 if (sig > SIGRTMAX)
136 return SIGUNKNOWN;
137 else if (sig >= SIGRTMIN)
138 return sig - SIGRTMIN + SIGRT_BASE;
139 else if (sig < MAXMAPPED_SIG)
140 return sig_map[sig];
141 return SIGUNKNOWN;
142}
143
144/**
145 * audit_file_mask - convert mask to permission string
146 * @buffer: buffer to write string to (NOT NULL)
147 * @mask: permission mask to convert
148 */
149static void audit_signal_mask(struct audit_buffer *ab, u32 mask)
150{
151 if (mask & MAY_READ)
152 audit_log_string(ab, "receive");
153 if (mask & MAY_WRITE)
154 audit_log_string(ab, "send");
155}
156
157/**
158 * audit_cb - call back for signal specific audit fields
159 * @ab: audit_buffer (NOT NULL)
160 * @va: audit struct to audit values of (NOT NULL)
161 */
162static void audit_signal_cb(struct audit_buffer *ab, void *va)
163{
164 struct common_audit_data *sa = va;
165
166 if (aad(sa)->request & AA_SIGNAL_PERM_MASK) {
167 audit_log_format(ab, " requested_mask=");
168 audit_signal_mask(ab, aad(sa)->request);
169 if (aad(sa)->denied & AA_SIGNAL_PERM_MASK) {
170 audit_log_format(ab, " denied_mask=");
171 audit_signal_mask(ab, aad(sa)->denied);
172 }
173 }
174 if (aad(sa)->signal == SIGUNKNOWN)
175 audit_log_format(ab, "signal=unknown(%d)",
176 aad(sa)->unmappedsig);
177 else if (aad(sa)->signal < MAXMAPPED_SIGNAME)
178 audit_log_format(ab, " signal=%s", sig_names[aad(sa)->signal]);
179 else
180 audit_log_format(ab, " signal=rtmin+%d",
181 aad(sa)->signal - SIGRT_BASE);
182 audit_log_format(ab, " peer=");
183 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
184 FLAGS_NONE, GFP_ATOMIC);
185}
186
187static int profile_signal_perm(struct aa_profile *profile,
188 struct aa_label *peer, u32 request,
189 struct common_audit_data *sa)
190{
191 struct aa_perms perms;
192 unsigned int state;
193
194 if (profile_unconfined(profile) ||
195 !PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
196 return 0;
197
198 aad(sa)->peer = peer;
199 /* TODO: secondary cache check <profile, profile, perm> */
200 state = aa_dfa_next(profile->policy.dfa,
201 profile->policy.start[AA_CLASS_SIGNAL],
202 aad(sa)->signal);
203 aa_label_match(profile, peer, state, false, request, &perms);
204 aa_apply_modes_to_perms(profile, &perms);
205 return aa_check_perms(profile, &perms, request, sa, audit_signal_cb);
206}
207
208int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
209{
210 struct aa_profile *profile;
211 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
212
213 aad(&sa)->signal = map_signal_num(sig);
214 aad(&sa)->unmappedsig = sig;
215 return xcheck_labels(sender, target, profile,
216 profile_signal_perm(profile, target, MAY_WRITE, &sa),
217 profile_signal_perm(profile, sender, MAY_READ, &sa));
218}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor ipc mediation
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2017 Canonical Ltd.
9 */
10
11#include <linux/gfp.h>
12
13#include "include/audit.h"
14#include "include/capability.h"
15#include "include/cred.h"
16#include "include/policy.h"
17#include "include/ipc.h"
18#include "include/sig_names.h"
19
20
21static inline int map_signal_num(int sig)
22{
23 if (sig > SIGRTMAX)
24 return SIGUNKNOWN;
25 else if (sig >= SIGRTMIN)
26 return sig - SIGRTMIN + SIGRT_BASE;
27 else if (sig < MAXMAPPED_SIG)
28 return sig_map[sig];
29 return SIGUNKNOWN;
30}
31
32/**
33 * audit_signal_mask - convert mask to permission string
34 * @mask: permission mask to convert
35 *
36 * Returns: pointer to static string
37 */
38static const char *audit_signal_mask(u32 mask)
39{
40 if (mask & MAY_READ)
41 return "receive";
42 if (mask & MAY_WRITE)
43 return "send";
44 return "";
45}
46
47/**
48 * audit_signal_cb() - call back for signal specific audit fields
49 * @ab: audit_buffer (NOT NULL)
50 * @va: audit struct to audit values of (NOT NULL)
51 */
52static void audit_signal_cb(struct audit_buffer *ab, void *va)
53{
54 struct common_audit_data *sa = va;
55 struct apparmor_audit_data *ad = aad(sa);
56
57 if (ad->request & AA_SIGNAL_PERM_MASK) {
58 audit_log_format(ab, " requested_mask=\"%s\"",
59 audit_signal_mask(ad->request));
60 if (ad->denied & AA_SIGNAL_PERM_MASK) {
61 audit_log_format(ab, " denied_mask=\"%s\"",
62 audit_signal_mask(ad->denied));
63 }
64 }
65 if (ad->signal == SIGUNKNOWN)
66 audit_log_format(ab, "signal=unknown(%d)",
67 ad->unmappedsig);
68 else if (ad->signal < MAXMAPPED_SIGNAME)
69 audit_log_format(ab, " signal=%s", sig_names[ad->signal]);
70 else
71 audit_log_format(ab, " signal=rtmin+%d",
72 ad->signal - SIGRT_BASE);
73 audit_log_format(ab, " peer=");
74 aa_label_xaudit(ab, labels_ns(ad->subj_label), ad->peer,
75 FLAGS_NONE, GFP_ATOMIC);
76}
77
78static int profile_signal_perm(const struct cred *cred,
79 struct aa_profile *profile,
80 struct aa_label *peer, u32 request,
81 struct apparmor_audit_data *ad)
82{
83 struct aa_ruleset *rules = list_first_entry(&profile->rules,
84 typeof(*rules), list);
85 struct aa_perms perms;
86 aa_state_t state;
87
88 if (profile_unconfined(profile) ||
89 !ANY_RULE_MEDIATES(&profile->rules, AA_CLASS_SIGNAL))
90 return 0;
91
92 ad->subj_cred = cred;
93 ad->peer = peer;
94 /* TODO: secondary cache check <profile, profile, perm> */
95 state = aa_dfa_next(rules->policy->dfa,
96 rules->policy->start[AA_CLASS_SIGNAL],
97 ad->signal);
98 aa_label_match(profile, rules, peer, state, false, request, &perms);
99 aa_apply_modes_to_perms(profile, &perms);
100 return aa_check_perms(profile, &perms, request, ad, audit_signal_cb);
101}
102
103int aa_may_signal(const struct cred *subj_cred, struct aa_label *sender,
104 const struct cred *target_cred, struct aa_label *target,
105 int sig)
106{
107 struct aa_profile *profile;
108 DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_SIGNAL, OP_SIGNAL);
109
110 ad.signal = map_signal_num(sig);
111 ad.unmappedsig = sig;
112 return xcheck_labels(sender, target, profile,
113 profile_signal_perm(subj_cred, profile, target,
114 MAY_WRITE, &ad),
115 profile_signal_perm(target_cred, profile, sender,
116 MAY_READ, &ad));
117}