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