security/tomoyo/environ.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * security/tomoyo/environ.c
   4  *
   5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   6  */
   7
   8 #include "common.h"
   9
  10 /**
  11  * tomoyo_check_env_acl - Check permission for environment variable's name.
  12  *
  13  * @r:   Pointer to "struct tomoyo_request_info".
  14  * @ptr: Pointer to "struct tomoyo_acl_info".
  15  *
  16  * Returns true if granted, false otherwise.
  17  */
  18 static bool tomoyo_check_env_acl(struct tomoyo_request_info *r,
  19                                  const struct tomoyo_acl_info *ptr)
  20 {
  21         const struct tomoyo_env_acl *acl =
  22                 container_of(ptr, typeof(*acl), head);
  23
  24         return tomoyo_path_matches_pattern(r->param.environ.name, acl->env);
  25 }
  26
  27 /**
  28  * tomoyo_audit_env_log - Audit environment variable name log.
  29  *
  30  * @r: Pointer to "struct tomoyo_request_info".
  31  *
  32  * Returns 0 on success, negative value otherwise.
  33  */
  34 static int tomoyo_audit_env_log(struct tomoyo_request_info *r)
  35 {
  36         return tomoyo_supervisor(r, "misc env %s\n",
  37                                  r->param.environ.name->name);
  38 }
  39
  40 /**
  41  * tomoyo_env_perm - Check permission for environment variable's name.
  42  *
  43  * @r:   Pointer to "struct tomoyo_request_info".
  44  * @env: The name of environment variable.
  45  *
  46  * Returns 0 on success, negative value otherwise.
  47  *
  48  * Caller holds tomoyo_read_lock().
  49  */
  50 int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env)
  51 {
  52         struct tomoyo_path_info environ;
  53         int error;
  54
  55         if (!env || !*env)
  56                 return 0;
  57         environ.name = env;
  58         tomoyo_fill_path_info(&environ);
  59         r->param_type = TOMOYO_TYPE_ENV_ACL;
  60         r->param.environ.name = &environ;
  61         do {
  62                 tomoyo_check_acl(r, tomoyo_check_env_acl);
  63                 error = tomoyo_audit_env_log(r);
  64         } while (error == TOMOYO_RETRY_REQUEST);
  65         return error;
  66 }
  67
  68 /**
  69  * tomoyo_same_env_acl - Check for duplicated "struct tomoyo_env_acl" entry.
  70  *
  71  * @a: Pointer to "struct tomoyo_acl_info".
  72  * @b: Pointer to "struct tomoyo_acl_info".
  73  *
  74  * Returns true if @a == @b, false otherwise.
  75  */
  76 static bool tomoyo_same_env_acl(const struct tomoyo_acl_info *a,
  77                                 const struct tomoyo_acl_info *b)
  78 {
  79         const struct tomoyo_env_acl *p1 = container_of(a, typeof(*p1), head);
  80         const struct tomoyo_env_acl *p2 = container_of(b, typeof(*p2), head);
  81
  82         return p1->env == p2->env;
  83 }
  84
  85 /**
  86  * tomoyo_write_env - Write "struct tomoyo_env_acl" list.
  87  *
  88  * @param: Pointer to "struct tomoyo_acl_param".
  89  *
  90  * Returns 0 on success, negative value otherwise.
  91  *
  92  * Caller holds tomoyo_read_lock().
  93  */
  94 static int tomoyo_write_env(struct tomoyo_acl_param *param)
  95 {
  96         struct tomoyo_env_acl e = { .head.type = TOMOYO_TYPE_ENV_ACL };
  97         int error = -ENOMEM;
  98         const char *data = tomoyo_read_token(param);
  99
 100         if (!tomoyo_correct_word(data) || strchr(data, '='))
 101                 return -EINVAL;
 102         e.env = tomoyo_get_name(data);
 103         if (!e.env)
 104                 return error;
 105         error = tomoyo_update_domain(&e.head, sizeof(e), param,
 106                                   tomoyo_same_env_acl, NULL);
 107         tomoyo_put_name(e.env);
 108         return error;
 109 }
 110
 111 /**
 112  * tomoyo_write_misc - Update environment variable list.
 113  *
 114  * @param: Pointer to "struct tomoyo_acl_param".
 115  *
 116  * Returns 0 on success, negative value otherwise.
 117  */
 118 int tomoyo_write_misc(struct tomoyo_acl_param *param)
 119 {
 120         if (tomoyo_str_starts(&param->data, "env "))
 121                 return tomoyo_write_env(param);
 122         return -EINVAL;
 123 }