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// SPDX-License-Identifier: GPL-2.0-only
/*
* AppArmor security module
*
* This file contains AppArmor ipc mediation
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2017 Canonical Ltd.
*/
#include <linux/gfp.h>
#include "include/audit.h"
#include "include/capability.h"
#include "include/cred.h"
#include "include/policy.h"
#include "include/ipc.h"
#include "include/sig_names.h"
static inline int map_signal_num(int sig)
{
if (sig > SIGRTMAX)
return SIGUNKNOWN;
else if (sig >= SIGRTMIN)
return sig - SIGRTMIN + SIGRT_BASE;
else if (sig < MAXMAPPED_SIG)
return sig_map[sig];
return SIGUNKNOWN;
}
/**
* audit_signal_mask - convert mask to permission string
* @mask: permission mask to convert
*
* Returns: pointer to static string
*/
static const char *audit_signal_mask(u32 mask)
{
if (mask & MAY_READ)
return "receive";
if (mask & MAY_WRITE)
return "send";
return "";
}
/**
* audit_signal_cb() - call back for signal specific audit fields
* @ab: audit_buffer (NOT NULL)
* @va: audit struct to audit values of (NOT NULL)
*/
static void audit_signal_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
struct apparmor_audit_data *ad = aad(sa);
if (ad->request & AA_SIGNAL_PERM_MASK) {
audit_log_format(ab, " requested_mask=\"%s\"",
audit_signal_mask(ad->request));
if (ad->denied & AA_SIGNAL_PERM_MASK) {
audit_log_format(ab, " denied_mask=\"%s\"",
audit_signal_mask(ad->denied));
}
}
if (ad->signal == SIGUNKNOWN)
audit_log_format(ab, "signal=unknown(%d)",
ad->unmappedsig);
else if (ad->signal < MAXMAPPED_SIGNAME)
audit_log_format(ab, " signal=%s", sig_names[ad->signal]);
else
audit_log_format(ab, " signal=rtmin+%d",
ad->signal - SIGRT_BASE);
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(ad->subj_label), ad->peer,
FLAGS_NONE, GFP_ATOMIC);
}
static int profile_signal_perm(const struct cred *cred,
struct aa_profile *profile,
struct aa_label *peer, u32 request,
struct apparmor_audit_data *ad)
{
struct aa_ruleset *rules = list_first_entry(&profile->rules,
typeof(*rules), list);
struct aa_perms perms;
aa_state_t state;
if (profile_unconfined(profile) ||
!ANY_RULE_MEDIATES(&profile->rules, AA_CLASS_SIGNAL))
return 0;
ad->subj_cred = cred;
ad->peer = peer;
/* TODO: secondary cache check <profile, profile, perm> */
state = aa_dfa_next(rules->policy->dfa,
rules->policy->start[AA_CLASS_SIGNAL],
ad->signal);
aa_label_match(profile, rules, peer, state, false, request, &perms);
aa_apply_modes_to_perms(profile, &perms);
return aa_check_perms(profile, &perms, request, ad, audit_signal_cb);
}
int aa_may_signal(const struct cred *subj_cred, struct aa_label *sender,
const struct cred *target_cred, struct aa_label *target,
int sig)
{
struct aa_profile *profile;
DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_SIGNAL, OP_SIGNAL);
ad.signal = map_signal_num(sig);
ad.unmappedsig = sig;
return xcheck_labels(sender, target, profile,
profile_signal_perm(subj_cred, profile, target,
MAY_WRITE, &ad),
profile_signal_perm(target_cred, profile, sender,
MAY_READ, &ad));
}
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