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