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0ed3b28a JJ |
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/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 | ||
26 | /* audit callback for resource specific fields */ | |
27 | static void audit_cb(struct audit_buffer *ab, void *va) | |
28 | { | |
29 | struct common_audit_data *sa = va; | |
30 | ||
31 | audit_log_format(ab, " rlimit=%s value=%lu", | |
32 | rlim_names[sa->aad.rlim.rlim], sa->aad.rlim.max); | |
33 | } | |
34 | ||
35 | /** | |
36 | * audit_resource - audit setting resource limit | |
37 | * @profile: profile being enforced (NOT NULL) | |
38 | * @resoure: rlimit being auditing | |
39 | * @value: value being set | |
40 | * @error: error value | |
41 | * | |
42 | * Returns: 0 or sa->error else other error code on failure | |
43 | */ | |
44 | static int audit_resource(struct aa_profile *profile, unsigned int resource, | |
45 | unsigned long value, int error) | |
46 | { | |
47 | struct common_audit_data sa; | |
48 | ||
49 | COMMON_AUDIT_DATA_INIT(&sa, NONE); | |
50 | sa.aad.op = OP_SETRLIMIT, | |
51 | sa.aad.rlim.rlim = resource; | |
52 | sa.aad.rlim.max = value; | |
53 | sa.aad.error = error; | |
54 | return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_KERNEL, &sa, | |
55 | audit_cb); | |
56 | } | |
57 | ||
58 | /** | |
59 | * aa_map_resouce - map compiled policy resource to internal # | |
60 | * @resource: flattened policy resource number | |
61 | * | |
62 | * Returns: resource # for the current architecture. | |
63 | * | |
64 | * rlimit resource can vary based on architecture, map the compiled policy | |
65 | * resource # to the internal representation for the architecture. | |
66 | */ | |
67 | int aa_map_resource(int resource) | |
68 | { | |
69 | return rlim_map[resource]; | |
70 | } | |
71 | ||
72 | /** | |
73 | * aa_task_setrlimit - test permission to set an rlimit | |
74 | * @profile - profile confining the task (NOT NULL) | |
75 | * @resource - the resource being set | |
76 | * @new_rlim - the new resource limit (NOT NULL) | |
77 | * | |
78 | * Control raising the processes hard limit. | |
79 | * | |
80 | * Returns: 0 or error code if setting resource failed | |
81 | */ | |
82 | int aa_task_setrlimit(struct aa_profile *profile, unsigned int resource, | |
83 | struct rlimit *new_rlim) | |
84 | { | |
85 | int error = 0; | |
86 | ||
87 | if (profile->rlimits.mask & (1 << resource) && | |
88 | new_rlim->rlim_max > profile->rlimits.limits[resource].rlim_max) | |
89 | ||
90 | error = audit_resource(profile, resource, new_rlim->rlim_max, | |
91 | -EACCES); | |
92 | ||
93 | return error; | |
94 | } | |
95 | ||
96 | /** | |
97 | * __aa_transition_rlimits - apply new profile rlimits | |
98 | * @old: old profile on task (NOT NULL) | |
99 | * @new: new profile with rlimits to apply (NOT NULL) | |
100 | */ | |
101 | void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new) | |
102 | { | |
103 | unsigned int mask = 0; | |
104 | struct rlimit *rlim, *initrlim; | |
105 | int i; | |
106 | ||
107 | /* for any rlimits the profile controlled reset the soft limit | |
108 | * to the less of the tasks hard limit and the init tasks soft limit | |
109 | */ | |
110 | if (old->rlimits.mask) { | |
111 | for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) { | |
112 | if (old->rlimits.mask & mask) { | |
113 | rlim = current->signal->rlim + i; | |
114 | initrlim = init_task.signal->rlim + i; | |
115 | rlim->rlim_cur = min(rlim->rlim_max, | |
116 | initrlim->rlim_cur); | |
117 | } | |
118 | } | |
119 | } | |
120 | ||
121 | /* set any new hard limits as dictated by the new profile */ | |
122 | if (!new->rlimits.mask) | |
123 | return; | |
124 | for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) { | |
125 | if (!(new->rlimits.mask & mask)) | |
126 | continue; | |
127 | ||
128 | rlim = current->signal->rlim + i; | |
129 | rlim->rlim_max = min(rlim->rlim_max, | |
130 | new->rlimits.limits[i].rlim_max); | |
131 | /* soft limit should not exceed hard limit */ | |
132 | rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max); | |
133 | } | |
134 | } |