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/*
* AppArmor security module
*
* This file contains AppArmor ipc mediation
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/gfp.h>
#include <linux/ptrace.h>
#include "include/audit.h"
#include "include/capability.h"
#include "include/context.h"
#include "include/policy.h"
#include "include/ipc.h"
/* call back to audit ptrace fields */
static void audit_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
audit_log_format(ab, " target=");
audit_log_untrustedstring(ab, sa->aad.target);
}
/**
* aa_audit_ptrace - do auditing for ptrace
* @profile: profile being enforced (NOT NULL)
* @target: profile being traced (NOT NULL)
* @error: error condition
*
* Returns: %0 or error code
*/
static int aa_audit_ptrace(struct aa_profile *profile,
struct aa_profile *target, int error)
{
struct common_audit_data sa;
COMMON_AUDIT_DATA_INIT(&sa, NONE);
sa.aad.op = OP_PTRACE;
sa.aad.target = target;
sa.aad.error = error;
return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_ATOMIC, &sa,
audit_cb);
}
/**
* aa_may_ptrace - test if tracer task can trace the tracee
* @tracer_task: task who will do the tracing (NOT NULL)
* @tracer: profile of the task doing the tracing (NOT NULL)
* @tracee: task to be traced
* @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH
*
* Returns: %0 else error code if permission denied or error
*/
int aa_may_ptrace(struct task_struct *tracer_task, struct aa_profile *tracer,
struct aa_profile *tracee, unsigned int mode)
{
/* TODO: currently only based on capability, not extended ptrace
* rules,
* Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH
*/
if (unconfined(tracer) || tracer == tracee)
return 0;
/* log this capability request */
return aa_capable(tracer_task, tracer, CAP_SYS_PTRACE, 1);
}
/**
* aa_ptrace - do ptrace permission check and auditing
* @tracer: task doing the tracing (NOT NULL)
* @tracee: task being traced (NOT NULL)
* @mode: ptrace mode either PTRACE_MODE_READ || PTRACE_MODE_ATTACH
*
* Returns: %0 else error code if permission denied or error
*/
int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee,
unsigned int mode)
{
/*
* tracer can ptrace tracee when
* - tracer is unconfined ||
* - tracer is in complain mode
* - tracer has rules allowing it to trace tracee currently this is:
* - confined by the same profile ||
* - tracer profile has CAP_SYS_PTRACE
*/
struct aa_profile *tracer_p;
/* cred released below */
const struct cred *cred = get_task_cred(tracer);
int error = 0;
tracer_p = aa_cred_profile(cred);
if (!unconfined(tracer_p)) {
/* lcred released below */
const struct cred *lcred = get_task_cred(tracee);
struct aa_profile *tracee_p = aa_cred_profile(lcred);
error = aa_may_ptrace(tracer, tracer_p, tracee_p, mode);
error = aa_audit_ptrace(tracer_p, tracee_p, error);
put_cred(lcred);
}
put_cred(cred);
return error;
}
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