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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// 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}