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kernel/linux-imx6_3.14.28/security/apparmor/ipc.c 2.96 KB
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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;
  	struct apparmor_audit_data aad = {0,};
  	sa.type = LSM_AUDIT_DATA_NONE;
  	sa.aad = &aad;
  	aad.op = OP_PTRACE;
  	aad.target = target;
  	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: 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 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, 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 = aa_get_task_profile(tracer);
  	int error = 0;
  
  	if (!unconfined(tracer_p)) {
  		struct aa_profile *tracee_p = aa_get_task_profile(tracee);
  
  		error = aa_may_ptrace(tracer_p, tracee_p, mode);
  		error = aa_audit_ptrace(tracer_p, tracee_p, error);
  
  		aa_put_profile(tracee_p);
  	}
  	aa_put_profile(tracer_p);
  
  	return error;
  }