linux-yocto/security/apparmor/ipc.c
John Johansen 90c436a64a apparmor: pass cred through to audit info.
The cred is needed to properly audit some messages, and will be needed
in the future for uid conditional mediation. So pass it through to
where the apparmor_audit_data struct gets defined.

Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-10-18 15:30:38 -07:00

118 lines
3.2 KiB
C

// 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));
}