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0ed3b28a JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor ipc mediation | |
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/gfp.h> | |
16 | #include <linux/ptrace.h> | |
17 | ||
18 | #include "include/audit.h" | |
19 | #include "include/capability.h" | |
20 | #include "include/context.h" | |
21 | #include "include/policy.h" | |
33f8bf58 | 22 | #include "include/ipc.h" |
0ed3b28a JJ |
23 | |
24 | /* call back to audit ptrace fields */ | |
25 | static void audit_cb(struct audit_buffer *ab, void *va) | |
26 | { | |
27 | struct common_audit_data *sa = va; | |
28 | audit_log_format(ab, " target="); | |
29 | audit_log_untrustedstring(ab, sa->aad.target); | |
30 | } | |
31 | ||
32 | /** | |
33 | * aa_audit_ptrace - do auditing for ptrace | |
34 | * @profile: profile being enforced (NOT NULL) | |
35 | * @target: profile being traced (NOT NULL) | |
36 | * @error: error condition | |
37 | * | |
38 | * Returns: %0 or error code | |
39 | */ | |
40 | static int aa_audit_ptrace(struct aa_profile *profile, | |
41 | struct aa_profile *target, int error) | |
42 | { | |
43 | struct common_audit_data sa; | |
44 | COMMON_AUDIT_DATA_INIT(&sa, NONE); | |
45 | sa.aad.op = OP_PTRACE; | |
46 | sa.aad.target = target; | |
47 | sa.aad.error = error; | |
48 | ||
49 | return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_ATOMIC, &sa, | |
50 | audit_cb); | |
51 | } | |
52 | ||
53 | /** | |
54 | * aa_may_ptrace - test if tracer task can trace the tracee | |
55 | * @tracer_task: task who will do the tracing (NOT NULL) | |
56 | * @tracer: profile of the task doing the tracing (NOT NULL) | |
57 | * @tracee: task to be traced | |
58 | * @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH | |
59 | * | |
60 | * Returns: %0 else error code if permission denied or error | |
61 | */ | |
62 | int aa_may_ptrace(struct task_struct *tracer_task, struct aa_profile *tracer, | |
63 | struct aa_profile *tracee, unsigned int mode) | |
64 | { | |
65 | /* TODO: currently only based on capability, not extended ptrace | |
66 | * rules, | |
67 | * Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH | |
68 | */ | |
69 | ||
70 | if (unconfined(tracer) || tracer == tracee) | |
71 | return 0; | |
72 | /* log this capability request */ | |
73 | return aa_capable(tracer_task, tracer, CAP_SYS_PTRACE, 1); | |
74 | } | |
75 | ||
76 | /** | |
77 | * aa_ptrace - do ptrace permission check and auditing | |
78 | * @tracer: task doing the tracing (NOT NULL) | |
79 | * @tracee: task being traced (NOT NULL) | |
80 | * @mode: ptrace mode either PTRACE_MODE_READ || PTRACE_MODE_ATTACH | |
81 | * | |
82 | * Returns: %0 else error code if permission denied or error | |
83 | */ | |
84 | int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee, | |
85 | unsigned int mode) | |
86 | { | |
87 | /* | |
88 | * tracer can ptrace tracee when | |
89 | * - tracer is unconfined || | |
90 | * - tracer is in complain mode | |
91 | * - tracer has rules allowing it to trace tracee currently this is: | |
92 | * - confined by the same profile || | |
93 | * - tracer profile has CAP_SYS_PTRACE | |
94 | */ | |
95 | ||
96 | struct aa_profile *tracer_p; | |
97 | /* cred released below */ | |
98 | const struct cred *cred = get_task_cred(tracer); | |
99 | int error = 0; | |
100 | tracer_p = aa_cred_profile(cred); | |
101 | ||
102 | if (!unconfined(tracer_p)) { | |
103 | /* lcred released below */ | |
77c80e6b | 104 | const struct cred *lcred = get_task_cred(tracee); |
0ed3b28a JJ |
105 | struct aa_profile *tracee_p = aa_cred_profile(lcred); |
106 | ||
107 | error = aa_may_ptrace(tracer, tracer_p, tracee_p, mode); | |
108 | error = aa_audit_ptrace(tracer_p, tracee_p, error); | |
109 | ||
110 | put_cred(lcred); | |
111 | } | |
112 | put_cred(cred); | |
113 | ||
114 | return error; | |
115 | } |