// 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 = profile->label.rules[0];	struct aa_perms perms;	aa_state_t state; 	if (profile_unconfined(profile))		return 0; 	ad->subj_cred = cred;	ad->peer = peer;	/* TODO: secondary cache check <profile, profile, perm> */	state = RULE_MEDIATES(rules, AA_CLASS_SIGNAL);	if (!state)		return 0;	state = aa_dfa_next(rules->policy->dfa, state, 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));}