check_proc_create.c

   1 /*
   2  * Copyright (C) 2010 Dan Carpenter.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 #include "smatch.h"
  19
  20 static int my_id;
  21
  22 static struct {
  23         int name_param;
  24         int mode_param;
  25 } param_index[] = {
  26         {.name_param = 0, .mode_param = 1},
  27         {.name_param = 1, .mode_param = 2},
  28 };
  29
  30 #define S_IWOTH 00002
  31
  32 static void match_create(const char *fn, struct expression *expr, void *_param_type)
  33 {
  34         struct expression *arg_expr;
  35         sval_t sval;
  36         char *name;
  37         int idx = PTR_INT(_param_type);
  38
  39         arg_expr = get_argument_from_call_expr(expr->args, param_index[idx].mode_param);
  40         if (!get_implied_value(arg_expr, &sval))
  41                 return;
  42         if (!(sval.uvalue & S_IWOTH))
  43                 return;
  44         arg_expr = get_argument_from_call_expr(expr->args, param_index[idx].name_param);
  45         name = expr_to_var(arg_expr);
  46         sm_msg("warn: proc file '%s' is world writable", name);
  47         free_string(name);
  48 }
  49
  50 void check_proc_create(int id)
  51 {
  52         my_id = id;
  53         if (option_project != PROJ_KERNEL)
  54                 return;
  55
  56         add_function_hook("proc_create", &match_create, INT_PTR(0));
  57         add_function_hook("create_proc_entry", &match_create, INT_PTR(0));
  58         add_function_hook("proc_create_data", &match_create, INT_PTR(0));
  59         add_function_hook("proc_net_fops_create", match_create, INT_PTR(1));
  60 }