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1/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor resource mediation and attachment
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/audit.h>
16
17#include "include/audit.h"
18#include "include/context.h"
19#include "include/resource.h"
20#include "include/policy.h"
21
22/*
23 * Table of rlimit names: we generate it from resource.h.
24 */
25#include "rlim_names.h"
26
27struct aa_fs_entry aa_fs_entry_rlimit[] = {
28 AA_FS_FILE_STRING("mask", AA_FS_RLIMIT_MASK),
29 { }
30};
31
32/* audit callback for resource specific fields */
33static void audit_cb(struct audit_buffer *ab, void *va)
34{
35 struct common_audit_data *sa = va;
36
37 audit_log_format(ab, " rlimit=%s value=%lu",
38 rlim_names[sa->aad->rlim.rlim], sa->aad->rlim.max);
39}
40
41/**
42 * audit_resource - audit setting resource limit
43 * @profile: profile being enforced (NOT NULL)
44 * @resoure: rlimit being auditing
45 * @value: value being set
46 * @error: error value
47 *
48 * Returns: 0 or sa->error else other error code on failure
49 */
50static int audit_resource(struct aa_profile *profile, unsigned int resource,
51 unsigned long value, int error)
52{
53 struct common_audit_data sa;
54 struct apparmor_audit_data aad = {0,};
55
56 sa.type = LSM_AUDIT_DATA_NONE;
57 sa.aad = &aad;
58 aad.op = OP_SETRLIMIT,
59 aad.rlim.rlim = resource;
60 aad.rlim.max = value;
61 aad.error = error;
62 return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_KERNEL, &sa,
63 audit_cb);
64}
65
66/**
67 * aa_map_resouce - map compiled policy resource to internal #
68 * @resource: flattened policy resource number
69 *
70 * Returns: resource # for the current architecture.
71 *
72 * rlimit resource can vary based on architecture, map the compiled policy
73 * resource # to the internal representation for the architecture.
74 */
75int aa_map_resource(int resource)
76{
77 return rlim_map[resource];
78}
79
80/**
81 * aa_task_setrlimit - test permission to set an rlimit
82 * @profile - profile confining the task (NOT NULL)
83 * @task - task the resource is being set on
84 * @resource - the resource being set
85 * @new_rlim - the new resource limit (NOT NULL)
86 *
87 * Control raising the processes hard limit.
88 *
89 * Returns: 0 or error code if setting resource failed
90 */
91int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task,
92 unsigned int resource, struct rlimit *new_rlim)
93{
94 struct aa_profile *task_profile;
95 int error = 0;
96
97 rcu_read_lock();
98 task_profile = aa_get_profile(aa_cred_profile(__task_cred(task)));
99 rcu_read_unlock();
100
101 /* TODO: extend resource control to handle other (non current)
102 * profiles. AppArmor rules currently have the implicit assumption
103 * that the task is setting the resource of a task confined with
104 * the same profile.
105 */
106 if (profile != task_profile ||
107 (profile->rlimits.mask & (1 << resource) &&
108 new_rlim->rlim_max > profile->rlimits.limits[resource].rlim_max))
109 error = -EACCES;
110
111 aa_put_profile(task_profile);
112
113 return audit_resource(profile, resource, new_rlim->rlim_max, error);
114}
115
116/**
117 * __aa_transition_rlimits - apply new profile rlimits
118 * @old: old profile on task (NOT NULL)
119 * @new: new profile with rlimits to apply (NOT NULL)
120 */
121void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new)
122{
123 unsigned int mask = 0;
124 struct rlimit *rlim, *initrlim;
125 int i;
126
127 /* for any rlimits the profile controlled reset the soft limit
128 * to the less of the tasks hard limit and the init tasks soft limit
129 */
130 if (old->rlimits.mask) {
131 for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
132 if (old->rlimits.mask & mask) {
133 rlim = current->signal->rlim + i;
134 initrlim = init_task.signal->rlim + i;
135 rlim->rlim_cur = min(rlim->rlim_max,
136 initrlim->rlim_cur);
137 }
138 }
139 }
140
141 /* set any new hard limits as dictated by the new profile */
142 if (!new->rlimits.mask)
143 return;
144 for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
145 if (!(new->rlimits.mask & mask))
146 continue;
147
148 rlim = current->signal->rlim + i;
149 rlim->rlim_max = min(rlim->rlim_max,
150 new->rlimits.limits[i].rlim_max);
151 /* soft limit should not exceed hard limit */
152 rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);
153 }
154}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor resource mediation and attachment
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 */
10
11#include <linux/audit.h>
12#include <linux/security.h>
13
14#include "include/audit.h"
15#include "include/cred.h"
16#include "include/resource.h"
17#include "include/policy.h"
18
19/*
20 * Table of rlimit names: we generate it from resource.h.
21 */
22#include "rlim_names.h"
23
24struct aa_sfs_entry aa_sfs_entry_rlimit[] = {
25 AA_SFS_FILE_STRING("mask", AA_SFS_RLIMIT_MASK),
26 { }
27};
28
29/* audit callback for resource specific fields */
30static void audit_cb(struct audit_buffer *ab, void *va)
31{
32 struct common_audit_data *sa = va;
33 struct apparmor_audit_data *ad = aad(sa);
34
35 audit_log_format(ab, " rlimit=%s value=%lu",
36 rlim_names[ad->rlim.rlim], ad->rlim.max);
37 if (ad->peer) {
38 audit_log_format(ab, " peer=");
39 aa_label_xaudit(ab, labels_ns(ad->subj_label), ad->peer,
40 FLAGS_NONE, GFP_ATOMIC);
41 }
42}
43
44/**
45 * audit_resource - audit setting resource limit
46 * @subj_cred: cred setting the resource
47 * @profile: profile being enforced (NOT NULL)
48 * @resource: rlimit being auditing
49 * @value: value being set
50 * @peer: aa_albel of the task being set
51 * @info: info being auditing
52 * @error: error value
53 *
54 * Returns: 0 or ad->error else other error code on failure
55 */
56static int audit_resource(const struct cred *subj_cred,
57 struct aa_profile *profile, unsigned int resource,
58 unsigned long value, struct aa_label *peer,
59 const char *info, int error)
60{
61 DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_RLIMITS,
62 OP_SETRLIMIT);
63
64 ad.subj_cred = subj_cred;
65 ad.rlim.rlim = resource;
66 ad.rlim.max = value;
67 ad.peer = peer;
68 ad.info = info;
69 ad.error = error;
70
71 return aa_audit(AUDIT_APPARMOR_AUTO, profile, &ad, audit_cb);
72}
73
74/**
75 * aa_map_resource - map compiled policy resource to internal #
76 * @resource: flattened policy resource number
77 *
78 * Returns: resource # for the current architecture.
79 *
80 * rlimit resource can vary based on architecture, map the compiled policy
81 * resource # to the internal representation for the architecture.
82 */
83int aa_map_resource(int resource)
84{
85 return rlim_map[resource];
86}
87
88static int profile_setrlimit(const struct cred *subj_cred,
89 struct aa_profile *profile, unsigned int resource,
90 struct rlimit *new_rlim)
91{
92 struct aa_ruleset *rules = list_first_entry(&profile->rules,
93 typeof(*rules), list);
94 int e = 0;
95
96 if (rules->rlimits.mask & (1 << resource) && new_rlim->rlim_max >
97 rules->rlimits.limits[resource].rlim_max)
98 e = -EACCES;
99 return audit_resource(subj_cred, profile, resource, new_rlim->rlim_max,
100 NULL, NULL, e);
101}
102
103/**
104 * aa_task_setrlimit - test permission to set an rlimit
105 * @subj_cred: cred setting the limit
106 * @label: label confining the task (NOT NULL)
107 * @task: task the resource is being set on
108 * @resource: the resource being set
109 * @new_rlim: the new resource limit (NOT NULL)
110 *
111 * Control raising the processes hard limit.
112 *
113 * Returns: 0 or error code if setting resource failed
114 */
115int aa_task_setrlimit(const struct cred *subj_cred, struct aa_label *label,
116 struct task_struct *task,
117 unsigned int resource, struct rlimit *new_rlim)
118{
119 struct aa_profile *profile;
120 struct aa_label *peer;
121 int error = 0;
122
123 rcu_read_lock();
124 peer = aa_get_newest_cred_label(__task_cred(task));
125 rcu_read_unlock();
126
127 /* TODO: extend resource control to handle other (non current)
128 * profiles. AppArmor rules currently have the implicit assumption
129 * that the task is setting the resource of a task confined with
130 * the same profile or that the task setting the resource of another
131 * task has CAP_SYS_RESOURCE.
132 */
133
134 if (label != peer &&
135 aa_capable(subj_cred, label, CAP_SYS_RESOURCE, CAP_OPT_NOAUDIT) != 0)
136 error = fn_for_each(label, profile,
137 audit_resource(subj_cred, profile, resource,
138 new_rlim->rlim_max, peer,
139 "cap_sys_resource", -EACCES));
140 else
141 error = fn_for_each_confined(label, profile,
142 profile_setrlimit(subj_cred, profile, resource,
143 new_rlim));
144 aa_put_label(peer);
145
146 return error;
147}
148
149/**
150 * __aa_transition_rlimits - apply new profile rlimits
151 * @old_l: old label on task (NOT NULL)
152 * @new_l: new label with rlimits to apply (NOT NULL)
153 */
154void __aa_transition_rlimits(struct aa_label *old_l, struct aa_label *new_l)
155{
156 unsigned int mask = 0;
157 struct rlimit *rlim, *initrlim;
158 struct aa_profile *old, *new;
159 struct label_it i;
160
161 old = labels_profile(old_l);
162 new = labels_profile(new_l);
163
164 /* for any rlimits the profile controlled, reset the soft limit
165 * to the lesser of the tasks hard limit and the init tasks soft limit
166 */
167 label_for_each_confined(i, old_l, old) {
168 struct aa_ruleset *rules = list_first_entry(&old->rules,
169 typeof(*rules),
170 list);
171 if (rules->rlimits.mask) {
172 int j;
173
174 for (j = 0, mask = 1; j < RLIM_NLIMITS; j++,
175 mask <<= 1) {
176 if (rules->rlimits.mask & mask) {
177 rlim = current->signal->rlim + j;
178 initrlim = init_task.signal->rlim + j;
179 rlim->rlim_cur = min(rlim->rlim_max,
180 initrlim->rlim_cur);
181 }
182 }
183 }
184 }
185
186 /* set any new hard limits as dictated by the new profile */
187 label_for_each_confined(i, new_l, new) {
188 struct aa_ruleset *rules = list_first_entry(&new->rules,
189 typeof(*rules),
190 list);
191 int j;
192
193 if (!rules->rlimits.mask)
194 continue;
195 for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, mask <<= 1) {
196 if (!(rules->rlimits.mask & mask))
197 continue;
198
199 rlim = current->signal->rlim + j;
200 rlim->rlim_max = min(rlim->rlim_max,
201 rules->rlimits.limits[j].rlim_max);
202 /* soft limit should not exceed hard limit */
203 rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);
204 }
205 }
206}