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" 22 #include "include/ipc.h" 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 */ 104 const struct cred *lcred = get_task_cred(tracee); 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 } 116