2 * AppArmor security module
4 * This file contains AppArmor ipc mediation
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2017 Canonical Ltd.
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
15 #include <linux/gfp.h>
16 #include <linux/ptrace.h>
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"
26 * audit_ptrace_mask - convert mask to permission string
27 * @buffer: buffer to write string to (NOT NULL)
28 * @mask: permission mask to convert
30 static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
34 audit_log_string(ab, "read");
37 audit_log_string(ab, "trace");
40 audit_log_string(ab, "readby");
42 case AA_MAY_BE_TRACED:
43 audit_log_string(ab, "tracedby");
48 /* call back to audit ptrace fields */
49 static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
51 struct common_audit_data *sa = va;
53 if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
54 audit_log_format(ab, " requested_mask=");
55 audit_ptrace_mask(ab, aad(sa)->request);
57 if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
58 audit_log_format(ab, " denied_mask=");
59 audit_ptrace_mask(ab, aad(sa)->denied);
62 audit_log_format(ab, " peer=");
63 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
64 FLAGS_NONE, GFP_ATOMIC);
67 /* assumes check for PROFILE_MEDIATES is already done */
68 /* TODO: conditionals */
69 static int profile_ptrace_perm(struct aa_profile *profile,
70 struct aa_label *peer, u32 request,
71 struct common_audit_data *sa)
73 struct aa_perms perms = { };
76 aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
78 aa_apply_modes_to_perms(profile, &perms);
79 return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
82 static int profile_tracee_perm(struct aa_profile *tracee,
83 struct aa_label *tracer, u32 request,
84 struct common_audit_data *sa)
86 if (profile_unconfined(tracee) || unconfined(tracer) ||
87 !PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
90 return profile_ptrace_perm(tracee, tracer, request, sa);
93 static int profile_tracer_perm(struct aa_profile *tracer,
94 struct aa_label *tracee, u32 request,
95 struct common_audit_data *sa)
97 if (profile_unconfined(tracer))
100 if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
101 return profile_ptrace_perm(tracer, tracee, request, sa);
103 /* profile uses the old style capability check for ptrace */
104 if (&tracer->label == tracee)
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);
112 return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
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
121 * Returns: %0 else error code if permission denied or error
123 int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
126 struct aa_profile *profile;
127 u32 xrequest = request << PTRACE_PERM_SHIFT;
128 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
130 return xcheck_labels(tracer, tracee, profile,
131 profile_tracer_perm(profile, tracee, request, &sa),
132 profile_tracee_perm(profile, tracer, xrequest, &sa));
136 static inline int map_signal_num(int sig)
140 else if (sig >= SIGRTMIN)
141 return sig - SIGRTMIN + SIGRT_BASE;
142 else if (sig < MAXMAPPED_SIG)
148 * audit_file_mask - convert mask to permission string
149 * @buffer: buffer to write string to (NOT NULL)
150 * @mask: permission mask to convert
152 static void audit_signal_mask(struct audit_buffer *ab, u32 mask)
155 audit_log_string(ab, "receive");
156 if (mask & MAY_WRITE)
157 audit_log_string(ab, "send");
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)
165 static void audit_signal_cb(struct audit_buffer *ab, void *va)
167 struct common_audit_data *sa = va;
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);
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]);
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);
190 static int profile_signal_perm(struct aa_profile *profile,
191 struct aa_label *peer, u32 request,
192 struct common_audit_data *sa)
194 struct aa_perms perms;
197 if (profile_unconfined(profile) ||
198 !PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
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],
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);
211 int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
213 struct aa_profile *profile;
214 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
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));