1 /* Test for vfprintf nargs allocation overflow (BZ #13656).
2 Copyright (C) 2012-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <stdint.h>
22 #include <unistd.h>
23 #include <inttypes.h>
24 #include <string.h>
25 #include <signal.h>
26
27 static int
format_failed(const char * fmt,const char * expected)28 format_failed (const char *fmt, const char *expected)
29 {
30 char output[80];
31
32 printf ("%s : ", fmt);
33
34 memset (output, 0, sizeof output);
35 /* Having sprintf itself detect a failure is good. */
36 if (sprintf (output, fmt, 1, 2, 3, "test") > 0
37 && strcmp (output, expected) != 0)
38 {
39 printf ("FAIL (output '%s' != expected '%s')\n", output, expected);
40 return 1;
41 }
42 puts ("ok");
43 return 0;
44 }
45
46 static int
do_test(void)47 do_test (void)
48 {
49 int rc = 0;
50 char buf[64];
51
52 /* Regular positionals work. */
53 if (format_failed ("%1$d", "1") != 0)
54 rc = 1;
55
56 /* Regular width positionals work. */
57 if (format_failed ("%1$*2$d", " 1") != 0)
58 rc = 1;
59
60 /* Positional arguments are constructed via read_int, so nargs can only
61 overflow on 32-bit systems. On 64-bit systems, it will attempt to
62 allocate a giant amount of memory and possibly crash, which is the
63 expected situation. Since the 64-bit behavior is arch-specific, only
64 test this on 32-bit systems. */
65 if (sizeof (long int) == 4)
66 {
67 sprintf (buf, "%%1$d %%%" PRIdPTR "$d",
68 (intptr_t) (UINT32_MAX / sizeof (int)));
69 if (format_failed (buf, "1 %$d") != 0)
70 rc = 1;
71 }
72
73 return rc;
74 }
75
76 #define TEST_FUNCTION do_test ()
77 #include "../test-skeleton.c"
78