1 // SPDX-License-Identifier: GPL-2.0-only
3 * AppArmor security module
5 * This file contains AppArmor ipc mediation
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2017 Canonical Ltd.
11 #include <linux/gfp.h>
12 #include <linux/ptrace.h>
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"
22 * audit_ptrace_mask - convert mask to permission string
23 * @buffer: buffer to write string to (NOT NULL)
24 * @mask: permission mask to convert
26 static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
30 audit_log_string(ab, "read");
33 audit_log_string(ab, "trace");
36 audit_log_string(ab, "readby");
38 case AA_MAY_BE_TRACED:
39 audit_log_string(ab, "tracedby");
44 /* call back to audit ptrace fields */
45 static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
47 struct common_audit_data *sa = va;
49 if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
50 audit_log_format(ab, " requested_mask=");
51 audit_ptrace_mask(ab, aad(sa)->request);
53 if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
54 audit_log_format(ab, " denied_mask=");
55 audit_ptrace_mask(ab, aad(sa)->denied);
58 audit_log_format(ab, " peer=");
59 aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
60 FLAGS_NONE, GFP_ATOMIC);
63 /* assumes check for PROFILE_MEDIATES is already done */
64 /* TODO: conditionals */
65 static int profile_ptrace_perm(struct aa_profile *profile,
66 struct aa_label *peer, u32 request,
67 struct common_audit_data *sa)
69 struct aa_perms perms = { };
72 aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
74 aa_apply_modes_to_perms(profile, &perms);
75 return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
78 static int profile_tracee_perm(struct aa_profile *tracee,
79 struct aa_label *tracer, u32 request,
80 struct common_audit_data *sa)
82 if (profile_unconfined(tracee) || unconfined(tracer) ||
83 !PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
86 return profile_ptrace_perm(tracee, tracer, request, sa);
89 static int profile_tracer_perm(struct aa_profile *tracer,
90 struct aa_label *tracee, u32 request,
91 struct common_audit_data *sa)
93 if (profile_unconfined(tracer))
96 if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
97 return profile_ptrace_perm(tracer, tracee, request, sa);
99 /* profile uses the old style capability check for ptrace */
100 if (&tracer->label == tracee)
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,
109 return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
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
118 * Returns: %0 else error code if permission denied or error
120 int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
123 struct aa_profile *profile;
124 u32 xrequest = request << PTRACE_PERM_SHIFT;
125 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
127 return xcheck_labels(tracer, tracee, profile,
128 profile_tracer_perm(profile, tracee, request, &sa),
129 profile_tracee_perm(profile, tracer, xrequest, &sa));
133 static inline int map_signal_num(int sig)
137 else if (sig >= SIGRTMIN)
138 return sig - SIGRTMIN + SIGRT_BASE;
139 else if (sig < MAXMAPPED_SIG)
145 * audit_file_mask - convert mask to permission string
146 * @buffer: buffer to write string to (NOT NULL)
147 * @mask: permission mask to convert
149 static void audit_signal_mask(struct audit_buffer *ab, u32 mask)
152 audit_log_string(ab, "receive");
153 if (mask & MAY_WRITE)
154 audit_log_string(ab, "send");
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)
162 static void audit_signal_cb(struct audit_buffer *ab, void *va)
164 struct common_audit_data *sa = va;
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);
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]);
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);
187 static int profile_signal_perm(struct aa_profile *profile,
188 struct aa_label *peer, u32 request,
189 struct common_audit_data *sa)
191 struct aa_perms perms;
194 if (profile_unconfined(profile) ||
195 !PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
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],
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);
208 int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
210 struct aa_profile *profile;
211 DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
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));