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>
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"
21 static inline int map_signal_num(int sig)
25 else if (sig >= SIGRTMIN)
26 return sig - SIGRTMIN + SIGRT_BASE;
27 else if (sig < MAXMAPPED_SIG)
33 * audit_signal_mask - convert mask to permission string
34 * @mask: permission mask to convert
36 * Returns: pointer to static string
38 static const char *audit_signal_mask(u32 mask)
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)
52 static void audit_signal_cb(struct audit_buffer *ab, void *va)
54 struct common_audit_data *sa = va;
55 struct apparmor_audit_data *ad = aad(sa);
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));
65 if (ad->signal == SIGUNKNOWN)
66 audit_log_format(ab, "signal=unknown(%d)",
68 else if (ad->signal < MAXMAPPED_SIGNAME)
69 audit_log_format(ab, " signal=%s", sig_names[ad->signal]);
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);
78 static int profile_signal_perm(struct aa_profile *profile,
79 struct aa_label *peer, u32 request,
80 struct apparmor_audit_data *ad)
82 struct aa_ruleset *rules = list_first_entry(&profile->rules,
83 typeof(*rules), list);
84 struct aa_perms perms;
87 if (profile_unconfined(profile) ||
88 !ANY_RULE_MEDIATES(&profile->rules, AA_CLASS_SIGNAL))
92 /* TODO: secondary cache check <profile, profile, perm> */
93 state = aa_dfa_next(rules->policy.dfa,
94 rules->policy.start[AA_CLASS_SIGNAL],
96 aa_label_match(profile, rules, peer, state, false, request, &perms);
97 aa_apply_modes_to_perms(profile, &perms);
98 return aa_check_perms(profile, &perms, request, ad, audit_signal_cb);
101 int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
103 struct aa_profile *profile;
104 DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_SIGNAL, OP_SIGNAL);
106 ad.signal = map_signal_num(sig);
107 ad.unmappedsig = sig;
108 return xcheck_labels(sender, target, profile,
109 profile_signal_perm(profile, target, MAY_WRITE, &ad),
110 profile_signal_perm(profile, sender, MAY_READ, &ad));