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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#include "include/ipc.h"
23
24/* call back to audit ptrace fields */
25static void audit_cb(struct audit_buffer *ab, void *va)
26{
27 struct common_audit_data *sa = va;
28 audit_log_format(ab, " target=");
29 audit_log_untrustedstring(ab, sa->aad->target);
30}
31
32/**
33 * aa_audit_ptrace - do auditing for ptrace
34 * @profile: profile being enforced (NOT NULL)
35 * @target: profile being traced (NOT NULL)
36 * @error: error condition
37 *
38 * Returns: %0 or error code
39 */
40static int aa_audit_ptrace(struct aa_profile *profile,
41 struct aa_profile *target, int error)
42{
43 struct common_audit_data sa;
44 struct apparmor_audit_data aad = {0,};
45 sa.type = LSM_AUDIT_DATA_NONE;
46 sa.aad = &aad;
47 aad.op = OP_PTRACE;
48 aad.target = target;
49 aad.error = error;
50
51 return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_ATOMIC, &sa,
52 audit_cb);
53}
54
55/**
56 * aa_may_ptrace - test if tracer task can trace the tracee
57 * @tracer: profile of the task doing the tracing (NOT NULL)
58 * @tracee: task to be traced
59 * @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH
60 *
61 * Returns: %0 else error code if permission denied or error
62 */
63int aa_may_ptrace(struct aa_profile *tracer, struct aa_profile *tracee,
64 unsigned int mode)
65{
66 /* TODO: currently only based on capability, not extended ptrace
67 * rules,
68 * Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH
69 */
70
71 if (unconfined(tracer) || tracer == tracee)
72 return 0;
73 /* log this capability request */
74 return aa_capable(tracer, CAP_SYS_PTRACE, 1);
75}
76
77/**
78 * aa_ptrace - do ptrace permission check and auditing
79 * @tracer: task doing the tracing (NOT NULL)
80 * @tracee: task being traced (NOT NULL)
81 * @mode: ptrace mode either PTRACE_MODE_READ || PTRACE_MODE_ATTACH
82 *
83 * Returns: %0 else error code if permission denied or error
84 */
85int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee,
86 unsigned int mode)
87{
88 /*
89 * tracer can ptrace tracee when
90 * - tracer is unconfined ||
91 * - tracer is in complain mode
92 * - tracer has rules allowing it to trace tracee currently this is:
93 * - confined by the same profile ||
94 * - tracer profile has CAP_SYS_PTRACE
95 */
96
97 struct aa_profile *tracer_p = aa_get_task_profile(tracer);
98 int error = 0;
99
100 if (!unconfined(tracer_p)) {
101 struct aa_profile *tracee_p = aa_get_task_profile(tracee);
102
103 error = aa_may_ptrace(tracer_p, tracee_p, mode);
104 error = aa_audit_ptrace(tracer_p, tracee_p, error);
105
106 aa_put_profile(tracee_p);
107 }
108 aa_put_profile(tracer_p);
109
110 return error;
111}
1/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor ipc mediation
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2017 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/cred.h"
21#include "include/policy.h"
22#include "include/ipc.h"
23#include "include/sig_names.h"
24
25/**
26 * audit_ptrace_mask - convert mask to permission string
27 * @buffer: buffer to write string to (NOT NULL)
28 * @mask: permission mask to convert
29 */
30static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
31{
32 switch (mask) {
33 case MAY_READ:
34 audit_log_string(ab, "read");
35 break;
36 case MAY_WRITE:
37 audit_log_string(ab, "trace");
38 break;
39 case AA_MAY_BE_READ:
40 audit_log_string(ab, "readby");
41 break;
42 case AA_MAY_BE_TRACED:
43 audit_log_string(ab, "tracedby");
44 break;
45 }
46}
47
48/* call back to audit ptrace fields */
49static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
50{
51 struct common_audit_data *sa = va;
52
53 if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
54 audit_log_format(ab, " requested_mask=");
55 audit_ptrace_mask(ab, aad(sa)->request);
56
57 if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
58 audit_log_format(ab, " denied_mask=");
59 audit_ptrace_mask(ab, aad(sa)->denied);
60 }
61 }
62 audit_log_format(ab, " peer=");
63 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
64 FLAGS_NONE, GFP_ATOMIC);
65}
66
67/* assumes check for PROFILE_MEDIATES is already done */
68/* TODO: conditionals */
69static int profile_ptrace_perm(struct aa_profile *profile,
70 struct aa_label *peer, u32 request,
71 struct common_audit_data *sa)
72{
73 struct aa_perms perms = { };
74
75 aad(sa)->peer = peer;
76 aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
77 &perms);
78 aa_apply_modes_to_perms(profile, &perms);
79 return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
80}
81
82static int profile_tracee_perm(struct aa_profile *tracee,
83 struct aa_label *tracer, u32 request,
84 struct common_audit_data *sa)
85{
86 if (profile_unconfined(tracee) || unconfined(tracer) ||
87 !PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
88 return 0;
89
90 return profile_ptrace_perm(tracee, tracer, request, sa);
91}
92
93static int profile_tracer_perm(struct aa_profile *tracer,
94 struct aa_label *tracee, u32 request,
95 struct common_audit_data *sa)
96{
97 if (profile_unconfined(tracer))
98 return 0;
99
100 if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
101 return profile_ptrace_perm(tracer, tracee, request, sa);
102
103 /* profile uses the old style capability check for ptrace */
104 if (&tracer->label == tracee)
105 return 0;
106
107 aad(sa)->label = &tracer->label;
108 aad(sa)->peer = tracee;
109 aad(sa)->request = 0;
110 aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE, 1);
111
112 return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
113}
114
115/**
116 * aa_may_ptrace - test if tracer task can trace the tracee
117 * @tracer: label of the task doing the tracing (NOT NULL)
118 * @tracee: task label to be traced
119 * @request: permission request
120 *
121 * Returns: %0 else error code if permission denied or error
122 */
123int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
124 u32 request)
125{
126 struct aa_profile *profile;
127 u32 xrequest = request << PTRACE_PERM_SHIFT;
128 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
129
130 return xcheck_labels(tracer, tracee, profile,
131 profile_tracer_perm(profile, tracee, request, &sa),
132 profile_tracee_perm(profile, tracer, xrequest, &sa));
133}
134
135
136static inline int map_signal_num(int sig)
137{
138 if (sig > SIGRTMAX)
139 return SIGUNKNOWN;
140 else if (sig >= SIGRTMIN)
141 return sig - SIGRTMIN + SIGRT_BASE;
142 else if (sig < MAXMAPPED_SIG)
143 return sig_map[sig];
144 return SIGUNKNOWN;
145}
146
147/**
148 * audit_file_mask - convert mask to permission string
149 * @buffer: buffer to write string to (NOT NULL)
150 * @mask: permission mask to convert
151 */
152static void audit_signal_mask(struct audit_buffer *ab, u32 mask)
153{
154 if (mask & MAY_READ)
155 audit_log_string(ab, "receive");
156 if (mask & MAY_WRITE)
157 audit_log_string(ab, "send");
158}
159
160/**
161 * audit_cb - call back for signal specific audit fields
162 * @ab: audit_buffer (NOT NULL)
163 * @va: audit struct to audit values of (NOT NULL)
164 */
165static void audit_signal_cb(struct audit_buffer *ab, void *va)
166{
167 struct common_audit_data *sa = va;
168
169 if (aad(sa)->request & AA_SIGNAL_PERM_MASK) {
170 audit_log_format(ab, " requested_mask=");
171 audit_signal_mask(ab, aad(sa)->request);
172 if (aad(sa)->denied & AA_SIGNAL_PERM_MASK) {
173 audit_log_format(ab, " denied_mask=");
174 audit_signal_mask(ab, aad(sa)->denied);
175 }
176 }
177 if (aad(sa)->signal == SIGUNKNOWN)
178 audit_log_format(ab, "signal=unknown(%d)",
179 aad(sa)->unmappedsig);
180 else if (aad(sa)->signal < MAXMAPPED_SIGNAME)
181 audit_log_format(ab, " signal=%s", sig_names[aad(sa)->signal]);
182 else
183 audit_log_format(ab, " signal=rtmin+%d",
184 aad(sa)->signal - SIGRT_BASE);
185 audit_log_format(ab, " peer=");
186 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
187 FLAGS_NONE, GFP_ATOMIC);
188}
189
190static int profile_signal_perm(struct aa_profile *profile,
191 struct aa_label *peer, u32 request,
192 struct common_audit_data *sa)
193{
194 struct aa_perms perms;
195 unsigned int state;
196
197 if (profile_unconfined(profile) ||
198 !PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
199 return 0;
200
201 aad(sa)->peer = peer;
202 /* TODO: secondary cache check <profile, profile, perm> */
203 state = aa_dfa_next(profile->policy.dfa,
204 profile->policy.start[AA_CLASS_SIGNAL],
205 aad(sa)->signal);
206 aa_label_match(profile, peer, state, false, request, &perms);
207 aa_apply_modes_to_perms(profile, &perms);
208 return aa_check_perms(profile, &perms, request, sa, audit_signal_cb);
209}
210
211int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
212{
213 struct aa_profile *profile;
214 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
215
216 aad(&sa)->signal = map_signal_num(sig);
217 aad(&sa)->unmappedsig = sig;
218 return xcheck_labels(sender, target, profile,
219 profile_signal_perm(profile, target, MAY_WRITE, &sa),
220 profile_signal_perm(profile, sender, MAY_READ, &sa));
221}