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