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0ed3b28a JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor capability mediation functions | |
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/capability.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/gfp.h> | |
12eb87d5 | 18 | #include <linux/security.h> |
0ed3b28a JJ |
19 | |
20 | #include "include/apparmor.h" | |
21 | #include "include/capability.h" | |
22 | #include "include/context.h" | |
23 | #include "include/policy.h" | |
24 | #include "include/audit.h" | |
25 | ||
26 | /* | |
27 | * Table of capability names: we generate it from capabilities.h. | |
28 | */ | |
29 | #include "capability_names.h" | |
30 | ||
c97204ba JJ |
31 | struct aa_sfs_entry aa_sfs_entry_caps[] = { |
32 | AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK), | |
84f1f787 JJ |
33 | { } |
34 | }; | |
35 | ||
0ed3b28a JJ |
36 | struct audit_cache { |
37 | struct aa_profile *profile; | |
38 | kernel_cap_t caps; | |
39 | }; | |
40 | ||
41 | static DEFINE_PER_CPU(struct audit_cache, audit_cache); | |
42 | ||
43 | /** | |
44 | * audit_cb - call back for capability components of audit struct | |
45 | * @ab - audit buffer (NOT NULL) | |
46 | * @va - audit struct to audit data from (NOT NULL) | |
47 | */ | |
48 | static void audit_cb(struct audit_buffer *ab, void *va) | |
49 | { | |
50 | struct common_audit_data *sa = va; | |
c70c86c4 | 51 | |
0ed3b28a JJ |
52 | audit_log_format(ab, " capname="); |
53 | audit_log_untrustedstring(ab, capability_names[sa->u.cap]); | |
54 | } | |
55 | ||
56 | /** | |
57 | * audit_caps - audit a capability | |
c70c86c4 | 58 | * @sa: audit data |
dd0c6e86 | 59 | * @profile: profile being tested for confinement (NOT NULL) |
0ed3b28a JJ |
60 | * @cap: capability tested |
61 | * @error: error code returned by test | |
62 | * | |
63 | * Do auditing of capability and handle, audit/complain/kill modes switching | |
64 | * and duplicate message elimination. | |
65 | * | |
66 | * Returns: 0 or sa->error on success, error code on failure | |
67 | */ | |
c70c86c4 JJ |
68 | static int audit_caps(struct common_audit_data *sa, struct aa_profile *profile, |
69 | int cap, int error) | |
0ed3b28a JJ |
70 | { |
71 | struct audit_cache *ent; | |
72 | int type = AUDIT_APPARMOR_AUTO; | |
c70c86c4 JJ |
73 | |
74 | aad(sa)->error = error; | |
0ed3b28a JJ |
75 | |
76 | if (likely(!error)) { | |
77 | /* test if auditing is being forced */ | |
78 | if (likely((AUDIT_MODE(profile) != AUDIT_ALL) && | |
79 | !cap_raised(profile->caps.audit, cap))) | |
80 | return 0; | |
81 | type = AUDIT_APPARMOR_AUDIT; | |
82 | } else if (KILL_MODE(profile) || | |
83 | cap_raised(profile->caps.kill, cap)) { | |
84 | type = AUDIT_APPARMOR_KILL; | |
85 | } else if (cap_raised(profile->caps.quiet, cap) && | |
86 | AUDIT_MODE(profile) != AUDIT_NOQUIET && | |
87 | AUDIT_MODE(profile) != AUDIT_ALL) { | |
88 | /* quiet auditing */ | |
89 | return error; | |
90 | } | |
91 | ||
92 | /* Do simple duplicate message elimination */ | |
93 | ent = &get_cpu_var(audit_cache); | |
94 | if (profile == ent->profile && cap_raised(ent->caps, cap)) { | |
95 | put_cpu_var(audit_cache); | |
96 | if (COMPLAIN_MODE(profile)) | |
97 | return complain_error(error); | |
98 | return error; | |
99 | } else { | |
100 | aa_put_profile(ent->profile); | |
101 | ent->profile = aa_get_profile(profile); | |
102 | cap_raise(ent->caps, cap); | |
103 | } | |
104 | put_cpu_var(audit_cache); | |
105 | ||
c70c86c4 | 106 | return aa_audit(type, profile, sa, audit_cb); |
0ed3b28a JJ |
107 | } |
108 | ||
109 | /** | |
110 | * profile_capable - test if profile allows use of capability @cap | |
111 | * @profile: profile being enforced (NOT NULL, NOT unconfined) | |
112 | * @cap: capability to test if allowed | |
c70c86c4 JJ |
113 | * @audit: whether an audit record should be generated |
114 | * @sa: audit data (MAY BE NULL indicating no auditing) | |
0ed3b28a JJ |
115 | * |
116 | * Returns: 0 if allowed else -EPERM | |
117 | */ | |
c70c86c4 JJ |
118 | static int profile_capable(struct aa_profile *profile, int cap, int audit, |
119 | struct common_audit_data *sa) | |
0ed3b28a | 120 | { |
c70c86c4 JJ |
121 | int error; |
122 | ||
123 | if (cap_raised(profile->caps.allow, cap) && | |
124 | !cap_raised(profile->caps.denied, cap)) | |
125 | error = 0; | |
126 | else | |
127 | error = -EPERM; | |
128 | ||
129 | if (audit == SECURITY_CAP_NOAUDIT) { | |
130 | if (!COMPLAIN_MODE(profile)) | |
131 | return error; | |
132 | /* audit the cap request in complain mode but note that it | |
133 | * should be optional. | |
134 | */ | |
135 | aad(sa)->info = "optional: no audit"; | |
136 | } | |
137 | ||
138 | return audit_caps(sa, profile, cap, error); | |
0ed3b28a JJ |
139 | } |
140 | ||
141 | /** | |
142 | * aa_capable - test permission to use capability | |
c70c86c4 | 143 | * @label: label being tested for capability (NOT NULL) |
0ed3b28a JJ |
144 | * @cap: capability to be tested |
145 | * @audit: whether an audit record should be generated | |
146 | * | |
147 | * Look up capability in profile capability set. | |
148 | * | |
149 | * Returns: 0 on success, or else an error code. | |
150 | */ | |
c70c86c4 | 151 | int aa_capable(struct aa_label *label, int cap, int audit) |
0ed3b28a | 152 | { |
c70c86c4 JJ |
153 | struct aa_profile *profile; |
154 | int error = 0; | |
155 | DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE); | |
0ed3b28a | 156 | |
c70c86c4 JJ |
157 | sa.u.cap = cap; |
158 | error = fn_for_each_confined(label, profile, | |
159 | profile_capable(profile, cap, audit, &sa)); | |
0ed3b28a | 160 | |
c70c86c4 | 161 | return error; |
0ed3b28a | 162 | } |