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Diffstat (limited to 'debug/tst-sprintf-fortify-unchecked.c')
| -rw-r--r-- | debug/tst-sprintf-fortify-unchecked.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/debug/tst-sprintf-fortify-unchecked.c b/debug/tst-sprintf-fortify-unchecked.c new file mode 100644 index 0000000000..7c7bd1b5e4 --- /dev/null +++ b/debug/tst-sprintf-fortify-unchecked.c @@ -0,0 +1,126 @@ +/* Tests for fortified sprintf with unknown buffer bounds (bug 30039). + Copyright (C) 2023 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> |