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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/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor ipc mediation
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
13 */
14
15#include <linux/gfp.h>
16#include <linux/ptrace.h>
17
18#include "include/audit.h"
19#include "include/capability.h"
20#include "include/context.h"
21#include "include/policy.h"
22
23/* call back to audit ptrace fields */
24static void audit_cb(struct audit_buffer *ab, void *va)
25{
26 struct common_audit_data *sa = va;
27 audit_log_format(ab, " target=");
28 audit_log_untrustedstring(ab, sa->aad.target);
29}
30
31/**
32 * aa_audit_ptrace - do auditing for ptrace
33 * @profile: profile being enforced (NOT NULL)
34 * @target: profile being traced (NOT NULL)
35 * @error: error condition
36 *
37 * Returns: %0 or error code
38 */
39static int aa_audit_ptrace(struct aa_profile *profile,
40 struct aa_profile *target, int error)
41{
42 struct common_audit_data sa;
43 COMMON_AUDIT_DATA_INIT(&sa, NONE);
44 sa.aad.op = OP_PTRACE;
45 sa.aad.target = target;
46 sa.aad.error = error;
47
48 return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_ATOMIC, &sa,
49 audit_cb);
50}
51
52/**
53 * aa_may_ptrace - test if tracer task can trace the tracee
54 * @tracer_task: task who will do the tracing (NOT NULL)
55 * @tracer: profile of the task doing the tracing (NOT NULL)
56 * @tracee: task to be traced
57 * @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH
58 *
59 * Returns: %0 else error code if permission denied or error
60 */
61int aa_may_ptrace(struct task_struct *tracer_task, struct aa_profile *tracer,
62 struct aa_profile *tracee, unsigned int mode)
63{
64 /* TODO: currently only based on capability, not extended ptrace
65 * rules,
66 * Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH
67 */
68
69 if (unconfined(tracer) || tracer == tracee)
70 return 0;
71 /* log this capability request */
72 return aa_capable(tracer_task, tracer, CAP_SYS_PTRACE, 1);
73}
74
75/**
76 * aa_ptrace - do ptrace permission check and auditing
77 * @tracer: task doing the tracing (NOT NULL)
78 * @tracee: task being traced (NOT NULL)
79 * @mode: ptrace mode either PTRACE_MODE_READ || PTRACE_MODE_ATTACH
80 *
81 * Returns: %0 else error code if permission denied or error
82 */
83int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee,
84 unsigned int mode)
85{
86 /*
87 * tracer can ptrace tracee when
88 * - tracer is unconfined ||
89 * - tracer is in complain mode
90 * - tracer has rules allowing it to trace tracee currently this is:
91 * - confined by the same profile ||
92 * - tracer profile has CAP_SYS_PTRACE
93 */
94
95 struct aa_profile *tracer_p;
96 /* cred released below */
97 const struct cred *cred = get_task_cred(tracer);
98 int error = 0;
99 tracer_p = aa_cred_profile(cred);
100
101 if (!unconfined(tracer_p)) {
102 /* lcred released below */
103 const struct cred *lcred = get_task_cred(tracee);
104 struct aa_profile *tracee_p = aa_cred_profile(lcred);
105
106 error = aa_may_ptrace(tracer, tracer_p, tracee_p, mode);
107 error = aa_audit_ptrace(tracer_p, tracee_p, error);
108
109 put_cred(lcred);
110 }
111 put_cred(cred);
112
113 return error;
114}