glibc/debug/tst-sprintf-fortify-unchecked.c

127 lines
4.0 KiB
C
Raw Normal View History

/* Tests for fortified sprintf with unknown buffer bounds (bug 30039).
Copyright (C) 2023-2024 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <printf.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <support/check.h>
/* This test is not built with _FORTIFY_SOURCE. Instead it calls the
appropriate implementation directly. The fortify mode is specified
in this variable. */
static int fortify_mode;
/* This does not handle long-double redirects etc., but we test only
format strings that stay within the confines of the base
implementation. */
int __vsprintf_chk (char *s, int flag, size_t slen, const char *format,
va_list ap);
/* Invoke vsprintf or __vsprintf_chk according to fortify_mode. */
static int
my_vsprintf (char *buf, const char *format, va_list ap)
{
int result;
if (fortify_mode == 0)
result = vsprintf (buf, format, ap);
else
/* Call the fortified version with an unspecified length. */
result = __vsprintf_chk (buf, fortify_mode - 1, -1, format, ap);
return result;
}
/* Run one test, with the specified expected output. */
static void __attribute ((format (printf, 2, 3)))
do_check (const char *expected, const char *format, ...)
{
va_list ap;
va_start (ap, format);
char buf_expected[24];
memset (buf_expected, '@', sizeof (buf_expected));
TEST_VERIFY (strlen (expected) < sizeof (buf_expected));
strcpy (buf_expected, expected);
char buf[sizeof (buf_expected)];
memset (buf, '@', sizeof (buf));
int ret = my_vsprintf (buf, format, ap);
TEST_COMPARE_BLOB (buf_expected, sizeof (buf_expected), buf, sizeof (buf));
TEST_COMPARE (ret, strlen (expected));
va_end (ap);
}
/* Run the tests in all fortify modes. */
static void
do_tests (void)
{
for (fortify_mode = 0; fortify_mode <= 3; ++fortify_mode)
{
do_check ("0", "%d", 0);
do_check ("-2147483648", "%d", -2147483647 - 1);
do_check ("-9223372036854775808", "%lld", -9223372036854775807LL - 1);
do_check ("", "%s", "");
do_check (" ", "%22s", "");
do_check ("XXXXXXXXXXXXXXXXXXXXXX", "%s", "XXXXXXXXXXXXXXXXXXXXXX");
do_check ("1.125000", "%f", 1.125);
do_check ("1.125", "%g", 1.125);
do_check ("1.125", "%.8g", 1.125);
}
}
/* printf callback that falls back to the glibc-supplied
implementation. */
static int
dummy_printf_function (FILE *__stream,
const struct printf_info *__info,
const void *const *__args)
{
return -2; /* Request fallback. */
}
/* Likewise for the type information. */
static int
dummy_arginfo_function (const struct printf_info *info,
size_t n, int *argtypes, int *size)
{
return -1; /* Request fallback. */
}
static int
do_test (void)
{
do_tests ();
/* Activate __printf_function_invoke mode. */
register_printf_specifier ('d', dummy_printf_function,
dummy_arginfo_function);
register_printf_specifier ('g', dummy_printf_function,
dummy_arginfo_function);
register_printf_specifier ('s', dummy_printf_function,
dummy_arginfo_function);
/* Rerun the tests with callback functions. */
do_tests ();
return 0;
}
#include <support/test-driver.c>