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
match_strcpy(const char * fn,struct expression * expr,void * unused)20 static void match_strcpy(const char *fn, struct expression *expr, void *unused)
21 {
22 struct expression *dest;
23 struct expression *data;
24 char *dest_name = NULL;
25 char *data_name = NULL;
26 int dest_size;
27 int data_size;
28
29 dest = get_argument_from_call_expr(expr->args, 0);
30 data = get_argument_from_call_expr(expr->args, 1);
31 dest_size = get_array_size_bytes(dest);
32 if (!dest_size)
33 return;
34
35 data_size = get_size_from_strlen(data);
36 if (!data_size)
37 data_size = get_array_size_bytes(data);
38
39 /* If the size of both arrays is known and the destination
40 * buffer is larger than the source buffer, we're okay.
41 */
42 if (data_size && dest_size >= data_size)
43 return;
44
45 dest_name = expr_to_str(dest);
46 data_name = expr_to_str(data);
47
48 if (data_size)
49 sm_error("%s() '%s' too large for '%s' (%d vs %d)",
50 fn, data_name, dest_name, data_size, dest_size);
51 else if (option_spammy)
52 sm_warning("%s() '%s' of unknown size might be too large for '%s'",
53 fn, data_name, dest_name);
54
55 free_string(dest_name);
56 free_string(data_name);
57 }
58
check_strcpy_overflow(int id)59 void check_strcpy_overflow(int id)
60 {
61 add_function_hook("strcpy", &match_strcpy, NULL);
62 }
63