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