blob: e1f3d7ef2c54f75861d5bc85990f647cf7524b58 [file] [log] [blame]
John Johansen0ed3b282010-07-29 14:48:05 -07001/*
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/resource.h"
19#include "include/policy.h"
20
21/*
22 * Table of rlimit names: we generate it from resource.h.
23 */
24#include "rlim_names.h"
25
Kees Cookd384b0a2012-01-26 16:29:23 -080026struct aa_fs_entry aa_fs_entry_rlimit[] = {
27 AA_FS_FILE_STRING("mask", AA_FS_RLIMIT_MASK),
28 { }
29};
30
John Johansen0ed3b282010-07-29 14:48:05 -070031/* audit callback for resource specific fields */
32static void audit_cb(struct audit_buffer *ab, void *va)
33{
34 struct common_audit_data *sa = va;
35
36 audit_log_format(ab, " rlimit=%s value=%lu",
Eric Paris3b3b0e42012-04-03 09:37:02 -070037 rlim_names[sa->aad->rlim.rlim], sa->aad->rlim.max);
John Johansen0ed3b282010-07-29 14:48:05 -070038}
39
40/**
41 * audit_resource - audit setting resource limit
42 * @profile: profile being enforced (NOT NULL)
43 * @resoure: rlimit being auditing
44 * @value: value being set
45 * @error: error value
46 *
47 * Returns: 0 or sa->error else other error code on failure
48 */
49static int audit_resource(struct aa_profile *profile, unsigned int resource,
50 unsigned long value, int error)
51{
52 struct common_audit_data sa;
Eric Paris3b3b0e42012-04-03 09:37:02 -070053 struct apparmor_audit_data aad = {0,};
John Johansen0ed3b282010-07-29 14:48:05 -070054
Eric Paris50c205f2012-04-04 15:01:43 -040055 sa.type = LSM_AUDIT_DATA_NONE;
Eric Paris3b3b0e42012-04-03 09:37:02 -070056 sa.aad = &aad;
57 aad.op = OP_SETRLIMIT,
58 aad.rlim.rlim = resource;
59 aad.rlim.max = value;
60 aad.error = error;
John Johansen0ed3b282010-07-29 14:48:05 -070061 return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_KERNEL, &sa,
62 audit_cb);
63}
64
65/**
66 * aa_map_resouce - map compiled policy resource to internal #
67 * @resource: flattened policy resource number
68 *
69 * Returns: resource # for the current architecture.
70 *
71 * rlimit resource can vary based on architecture, map the compiled policy
72 * resource # to the internal representation for the architecture.
73 */
74int aa_map_resource(int resource)
75{
76 return rlim_map[resource];
77}
78
79/**
80 * aa_task_setrlimit - test permission to set an rlimit
81 * @profile - profile confining the task (NOT NULL)
John Johansen3a2dc832010-09-06 10:10:20 -070082 * @task - task the resource is being set on
John Johansen0ed3b282010-07-29 14:48:05 -070083 * @resource - the resource being set
84 * @new_rlim - the new resource limit (NOT NULL)
85 *
86 * Control raising the processes hard limit.
87 *
88 * Returns: 0 or error code if setting resource failed
89 */
John Johansen3a2dc832010-09-06 10:10:20 -070090int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task,
91 unsigned int resource, struct rlimit *new_rlim)
John Johansen0ed3b282010-07-29 14:48:05 -070092{
93 int error = 0;
94
John Johansen3a2dc832010-09-06 10:10:20 -070095 /* TODO: extend resource control to handle other (non current)
96 * processes. AppArmor rules currently have the implicit assumption
97 * that the task is setting the resource of the current process
98 */
99 if ((task != current->group_leader) ||
100 (profile->rlimits.mask & (1 << resource) &&
101 new_rlim->rlim_max > profile->rlimits.limits[resource].rlim_max))
102 error = -EACCES;
John Johansen0ed3b282010-07-29 14:48:05 -0700103
John Johansen3a2dc832010-09-06 10:10:20 -0700104 return audit_resource(profile, resource, new_rlim->rlim_max, error);
John Johansen0ed3b282010-07-29 14:48:05 -0700105}
106
107/**
108 * __aa_transition_rlimits - apply new profile rlimits
109 * @old: old profile on task (NOT NULL)
110 * @new: new profile with rlimits to apply (NOT NULL)
111 */
112void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new)
113{
114 unsigned int mask = 0;
115 struct rlimit *rlim, *initrlim;
116 int i;
117
118 /* for any rlimits the profile controlled reset the soft limit
119 * to the less of the tasks hard limit and the init tasks soft limit
120 */
121 if (old->rlimits.mask) {
122 for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
123 if (old->rlimits.mask & mask) {
124 rlim = current->signal->rlim + i;
125 initrlim = init_task.signal->rlim + i;
126 rlim->rlim_cur = min(rlim->rlim_max,
127 initrlim->rlim_cur);
128 }
129 }
130 }
131
132 /* set any new hard limits as dictated by the new profile */
133 if (!new->rlimits.mask)
134 return;
135 for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
136 if (!(new->rlimits.mask & mask))
137 continue;
138
139 rlim = current->signal->rlim + i;
140 rlim->rlim_max = min(rlim->rlim_max,
141 new->rlimits.limits[i].rlim_max);
142 /* soft limit should not exceed hard limit */
143 rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);
144 }
145}