1/*
  2 * AppArmor security module
  3 *
  4 * This file contains AppArmor capability mediation functions
  5 *
  6 * Copyright (C) 1998-2008 Novell/SUSE
  7 * Copyright 2009-2010 Canonical Ltd.
  8 *
  9 * This program is free software; you can redistribute it and/or
 10 * modify it under the terms of the GNU General Public License as
 11 * published by the Free Software Foundation, version 2 of the
 12 * License.
 13 */
 14
 15#include <linux/capability.h>
 16#include <linux/errno.h>
 17#include <linux/gfp.h>
 18#include <linux/security.h>
 19
 20#include "include/apparmor.h"
 21#include "include/capability.h"
 22#include "include/cred.h"
 23#include "include/policy.h"
 24#include "include/audit.h"
 25
 26/*
 27 * Table of capability names: we generate it from capabilities.h.
 28 */
 29#include "capability_names.h"
 30
 31struct aa_sfs_entry aa_sfs_entry_caps[] = {
 32	AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK),
 33	{ }
 34};
 35
 36struct audit_cache {
 37	struct aa_profile *profile;
 38	kernel_cap_t caps;
 39};
 40
 41static DEFINE_PER_CPU(struct audit_cache, audit_cache);
 42
 43/**
 44 * audit_cb - call back for capability components of audit struct
 45 * @ab - audit buffer   (NOT NULL)
 46 * @va - audit struct to audit data from  (NOT NULL)
 47 */
 48static void audit_cb(struct audit_buffer *ab, void *va)
 49{
 50	struct common_audit_data *sa = va;
 51
 52	audit_log_format(ab, " capname=");
 53	audit_log_untrustedstring(ab, capability_names[sa->u.cap]);
 54}
 55
 56/**
 57 * audit_caps - audit a capability
 58 * @sa: audit data
 59 * @profile: profile being tested for confinement (NOT NULL)
 60 * @cap: capability tested
 61 * @error: error code returned by test
 62 *
 63 * Do auditing of capability and handle, audit/complain/kill modes switching
 64 * and duplicate message elimination.
 65 *
 66 * Returns: 0 or sa->error on success,  error code on failure
 67 */
 68static int audit_caps(struct common_audit_data *sa, struct aa_profile *profile,
 69		      int cap, int error)
 70{
 
 
 71	struct audit_cache *ent;
 72	int type = AUDIT_APPARMOR_AUTO;
 73
 74	aad(sa)->error = error;
 75
 76	if (likely(!error)) {
 77		/* test if auditing is being forced */
 78		if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&
 79			   !cap_raised(profile->caps.audit, cap)))
 80			return 0;
 81		type = AUDIT_APPARMOR_AUDIT;
 82	} else if (KILL_MODE(profile) ||
 83		   cap_raised(profile->caps.kill, cap)) {
 84		type = AUDIT_APPARMOR_KILL;
 85	} else if (cap_raised(profile->caps.quiet, cap) &&
 86		   AUDIT_MODE(profile) != AUDIT_NOQUIET &&
 87		   AUDIT_MODE(profile) != AUDIT_ALL) {
 88		/* quiet auditing */
 89		return error;
 90	}
 91
 92	/* Do simple duplicate message elimination */
 93	ent = &get_cpu_var(audit_cache);
 94	if (profile == ent->profile && cap_raised(ent->caps, cap)) {
 95		put_cpu_var(audit_cache);
 96		if (COMPLAIN_MODE(profile))
 97			return complain_error(error);
 98		return error;
 99	} else {
100		aa_put_profile(ent->profile);
101		ent->profile = aa_get_profile(profile);
102		cap_raise(ent->caps, cap);
103	}
104	put_cpu_var(audit_cache);
105
106	return aa_audit(type, profile, sa, audit_cb);
107}
108
109/**
110 * profile_capable - test if profile allows use of capability @cap
111 * @profile: profile being enforced    (NOT NULL, NOT unconfined)
112 * @cap: capability to test if allowed
113 * @audit: whether an audit record should be generated
114 * @sa: audit data (MAY BE NULL indicating no auditing)
115 *
116 * Returns: 0 if allowed else -EPERM
117 */
118static int profile_capable(struct aa_profile *profile, int cap, int audit,
119			   struct common_audit_data *sa)
120{
 
 
121	int error;
122
123	if (cap_raised(profile->caps.allow, cap) &&
124	    !cap_raised(profile->caps.denied, cap))
125		error = 0;
126	else
127		error = -EPERM;
128
129	if (audit == SECURITY_CAP_NOAUDIT) {
130		if (!COMPLAIN_MODE(profile))
131			return error;
132		/* audit the cap request in complain mode but note that it
133		 * should be optional.
134		 */
135		aad(sa)->info = "optional: no audit";
136	}
137
138	return audit_caps(sa, profile, cap, error);
139}
140
141/**
142 * aa_capable - test permission to use capability
 
143 * @label: label being tested for capability (NOT NULL)
144 * @cap: capability to be tested
145 * @audit: whether an audit record should be generated
146 *
147 * Look up capability in profile capability set.
148 *
149 * Returns: 0 on success, or else an error code.
150 */
151int aa_capable(struct aa_label *label, int cap, int audit)
 
152{
153	struct aa_profile *profile;
154	int error = 0;
155	DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE);
156
157	sa.u.cap = cap;
 
158	error = fn_for_each_confined(label, profile,
159			profile_capable(profile, cap, audit, &sa));
160
161	return error;
162}

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * AppArmor security module
  4 *
  5 * This file contains AppArmor capability mediation functions
  6 *
  7 * Copyright (C) 1998-2008 Novell/SUSE
  8 * Copyright 2009-2010 Canonical Ltd.
 
 
 
 
 
  9 */
 10
 11#include <linux/capability.h>
 12#include <linux/errno.h>
 13#include <linux/gfp.h>
 14#include <linux/security.h>
 15
 16#include "include/apparmor.h"
 17#include "include/capability.h"
 18#include "include/cred.h"
 19#include "include/policy.h"
 20#include "include/audit.h"
 21
 22/*
 23 * Table of capability names: we generate it from capabilities.h.
 24 */
 25#include "capability_names.h"
 26
 27struct aa_sfs_entry aa_sfs_entry_caps[] = {
 28	AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK),
 29	{ }
 30};
 31
 32struct audit_cache {
 33	struct aa_profile *profile;
 34	kernel_cap_t caps;
 35};
 36
 37static DEFINE_PER_CPU(struct audit_cache, audit_cache);
 38
 39/**
 40 * audit_cb - call back for capability components of audit struct
 41 * @ab: audit buffer   (NOT NULL)
 42 * @va: audit struct to audit data from  (NOT NULL)
 43 */
 44static void audit_cb(struct audit_buffer *ab, void *va)
 45{
 46	struct common_audit_data *sa = va;
 47
 48	audit_log_format(ab, " capname=");
 49	audit_log_untrustedstring(ab, capability_names[sa->u.cap]);
 50}
 51
 52/**
 53 * audit_caps - audit a capability
 54 * @ad: audit data
 55 * @profile: profile being tested for confinement (NOT NULL)
 56 * @cap: capability tested
 57 * @error: error code returned by test
 58 *
 59 * Do auditing of capability and handle, audit/complain/kill modes switching
 60 * and duplicate message elimination.
 61 *
 62 * Returns: 0 or ad->error on success,  error code on failure
 63 */
 64static int audit_caps(struct apparmor_audit_data *ad, struct aa_profile *profile,
 65		      int cap, int error)
 66{
 67	struct aa_ruleset *rules = list_first_entry(&profile->rules,
 68						    typeof(*rules), list);
 69	struct audit_cache *ent;
 70	int type = AUDIT_APPARMOR_AUTO;
 71
 72	ad->error = error;
 73
 74	if (likely(!error)) {
 75		/* test if auditing is being forced */
 76		if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&
 77			   !cap_raised(rules->caps.audit, cap)))
 78			return 0;
 79		type = AUDIT_APPARMOR_AUDIT;
 80	} else if (KILL_MODE(profile) ||
 81		   cap_raised(rules->caps.kill, cap)) {
 82		type = AUDIT_APPARMOR_KILL;
 83	} else if (cap_raised(rules->caps.quiet, cap) &&
 84		   AUDIT_MODE(profile) != AUDIT_NOQUIET &&
 85		   AUDIT_MODE(profile) != AUDIT_ALL) {
 86		/* quiet auditing */
 87		return error;
 88	}
 89
 90	/* Do simple duplicate message elimination */
 91	ent = &get_cpu_var(audit_cache);
 92	if (profile == ent->profile && cap_raised(ent->caps, cap)) {
 93		put_cpu_var(audit_cache);
 94		if (COMPLAIN_MODE(profile))
 95			return complain_error(error);
 96		return error;
 97	} else {
 98		aa_put_profile(ent->profile);
 99		ent->profile = aa_get_profile(profile);
100		cap_raise(ent->caps, cap);
101	}
102	put_cpu_var(audit_cache);
103
104	return aa_audit(type, profile, ad, audit_cb);
105}
106
107/**
108 * profile_capable - test if profile allows use of capability @cap
109 * @profile: profile being enforced    (NOT NULL, NOT unconfined)
110 * @cap: capability to test if allowed
111 * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated
112 * @ad: audit data (MAY BE NULL indicating no auditing)
113 *
114 * Returns: 0 if allowed else -EPERM
115 */
116static int profile_capable(struct aa_profile *profile, int cap,
117			   unsigned int opts, struct apparmor_audit_data *ad)
118{
119	struct aa_ruleset *rules = list_first_entry(&profile->rules,
120						    typeof(*rules), list);
121	int error;
122
123	if (cap_raised(rules->caps.allow, cap) &&
124	    !cap_raised(rules->caps.denied, cap))
125		error = 0;
126	else
127		error = -EPERM;
128
129	if (opts & CAP_OPT_NOAUDIT) {
130		if (!COMPLAIN_MODE(profile))
131			return error;
132		/* audit the cap request in complain mode but note that it
133		 * should be optional.
134		 */
135		ad->info = "optional: no audit";
136	}
137
138	return audit_caps(ad, profile, cap, error);
139}
140
141/**
142 * aa_capable - test permission to use capability
143 * @subj_cred: cred we are testing capability against
144 * @label: label being tested for capability (NOT NULL)
145 * @cap: capability to be tested
146 * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated
147 *
148 * Look up capability in profile capability set.
149 *
150 * Returns: 0 on success, or else an error code.
151 */
152int aa_capable(const struct cred *subj_cred, struct aa_label *label,
153	       int cap, unsigned int opts)
154{
155	struct aa_profile *profile;
156	int error = 0;
157	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_CAP, AA_CLASS_CAP, OP_CAPABLE);
158
159	ad.subj_cred = subj_cred;
160	ad.common.u.cap = cap;
161	error = fn_for_each_confined(label, profile,
162			profile_capable(profile, cap, opts, &ad));
163
164	return error;
165}