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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> | |
18 | ||
19 | #include "include/apparmor.h" | |
20 | #include "include/capability.h" | |
21 | #include "include/context.h" | |
22 | #include "include/policy.h" | |
23 | #include "include/audit.h" | |
24 | ||
25 | /* | |
26 | * Table of capability names: we generate it from capabilities.h. | |
27 | */ | |
28 | #include "capability_names.h" | |
29 | ||
84f1f787 JJ |
30 | struct aa_fs_entry aa_fs_entry_caps[] = { |
31 | AA_FS_FILE_STRING("mask", AA_FS_CAPS_MASK), | |
32 | { } | |
33 | }; | |
34 | ||
0ed3b28a JJ |
35 | struct audit_cache { |
36 | struct aa_profile *profile; | |
37 | kernel_cap_t caps; | |
38 | }; | |
39 | ||
40 | static DEFINE_PER_CPU(struct audit_cache, audit_cache); | |
41 | ||
42 | /** | |
43 | * audit_cb - call back for capability components of audit struct | |
44 | * @ab - audit buffer (NOT NULL) | |
45 | * @va - audit struct to audit data from (NOT NULL) | |
46 | */ | |
47 | static void audit_cb(struct audit_buffer *ab, void *va) | |
48 | { | |
49 | struct common_audit_data *sa = va; | |
50 | audit_log_format(ab, " capname="); | |
51 | audit_log_untrustedstring(ab, capability_names[sa->u.cap]); | |
52 | } | |
53 | ||
54 | /** | |
55 | * audit_caps - audit a capability | |
56 | * @profile: profile confining task (NOT NULL) | |
57 | * @task: task capability test was performed against (NOT NULL) | |
58 | * @cap: capability tested | |
59 | * @error: error code returned by test | |
60 | * | |
61 | * Do auditing of capability and handle, audit/complain/kill modes switching | |
62 | * and duplicate message elimination. | |
63 | * | |
64 | * Returns: 0 or sa->error on success, error code on failure | |
65 | */ | |
66 | static int audit_caps(struct aa_profile *profile, struct task_struct *task, | |
67 | int cap, int error) | |
68 | { | |
69 | struct audit_cache *ent; | |
70 | int type = AUDIT_APPARMOR_AUTO; | |
71 | struct common_audit_data sa; | |
3b3b0e4f | 72 | struct apparmor_audit_data aad = {0,}; |
50c205f5 | 73 | sa.type = LSM_AUDIT_DATA_CAP; |
3b3b0e4f | 74 | sa.aad = &aad; |
0ed3b28a | 75 | sa.u.cap = cap; |
0972c74e | 76 | sa.aad->tsk = task; |
3b3b0e4f EP |
77 | sa.aad->op = OP_CAPABLE; |
78 | sa.aad->error = error; | |
0ed3b28a JJ |
79 | |
80 | if (likely(!error)) { | |
81 | /* test if auditing is being forced */ | |
82 | if (likely((AUDIT_MODE(profile) != AUDIT_ALL) && | |
83 | !cap_raised(profile->caps.audit, cap))) | |
84 | return 0; | |
85 | type = AUDIT_APPARMOR_AUDIT; | |
86 | } else if (KILL_MODE(profile) || | |
87 | cap_raised(profile->caps.kill, cap)) { | |
88 | type = AUDIT_APPARMOR_KILL; | |
89 | } else if (cap_raised(profile->caps.quiet, cap) && | |
90 | AUDIT_MODE(profile) != AUDIT_NOQUIET && | |
91 | AUDIT_MODE(profile) != AUDIT_ALL) { | |
92 | /* quiet auditing */ | |
93 | return error; | |
94 | } | |
95 | ||
96 | /* Do simple duplicate message elimination */ | |
97 | ent = &get_cpu_var(audit_cache); | |
98 | if (profile == ent->profile && cap_raised(ent->caps, cap)) { | |
99 | put_cpu_var(audit_cache); | |
100 | if (COMPLAIN_MODE(profile)) | |
101 | return complain_error(error); | |
102 | return error; | |
103 | } else { | |
104 | aa_put_profile(ent->profile); | |
105 | ent->profile = aa_get_profile(profile); | |
106 | cap_raise(ent->caps, cap); | |
107 | } | |
108 | put_cpu_var(audit_cache); | |
109 | ||
110 | return aa_audit(type, profile, GFP_ATOMIC, &sa, audit_cb); | |
111 | } | |
112 | ||
113 | /** | |
114 | * profile_capable - test if profile allows use of capability @cap | |
115 | * @profile: profile being enforced (NOT NULL, NOT unconfined) | |
116 | * @cap: capability to test if allowed | |
117 | * | |
118 | * Returns: 0 if allowed else -EPERM | |
119 | */ | |
120 | static int profile_capable(struct aa_profile *profile, int cap) | |
121 | { | |
122 | return cap_raised(profile->caps.allow, cap) ? 0 : -EPERM; | |
123 | } | |
124 | ||
125 | /** | |
126 | * aa_capable - test permission to use capability | |
127 | * @task: task doing capability test against (NOT NULL) | |
128 | * @profile: profile confining @task (NOT NULL) | |
129 | * @cap: capability to be tested | |
130 | * @audit: whether an audit record should be generated | |
131 | * | |
132 | * Look up capability in profile capability set. | |
133 | * | |
134 | * Returns: 0 on success, or else an error code. | |
135 | */ | |
136 | int aa_capable(struct task_struct *task, struct aa_profile *profile, int cap, | |
137 | int audit) | |
138 | { | |
139 | int error = profile_capable(profile, cap); | |
140 | ||
141 | if (!audit) { | |
142 | if (COMPLAIN_MODE(profile)) | |
143 | return complain_error(error); | |
144 | return error; | |
145 | } | |
146 | ||
147 | return audit_caps(profile, task, cap, error); | |
148 | } |