glibc/stdlib/tst-empty-env.c
Siddhesh Poyarekar 41389c4049 Fix environment traversal when an envvar value is empty
The condition when the value of an envvar is empty (not just '\0'),
the loop in tunables_init gets stuck infinitely because envp is not
incremented.  Fix that by always incrementing envp in the loop.

Added test case (tst-empty-env.c) verifies the fix when the source is
configured with --enable-hardcoded-path-in-tests, thanks Josh Stone for
providing the test case.  Verified on x86_64.

	* elf/dl-tunables (get_next_env): Always advance envp.
	* stdlib/tst-empty-env.c: New test case.
	* stdlib/Makefile (tests): Use it.
2017-01-20 00:45:09 +05:30

59 lines
1.9 KiB
C

/* Test that passing a NULL value does not hang environment traversal in
tunables.
Copyright (C) 2017 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
<http://www.gnu.org/licenses/>. */
/* The test is useful only when the source is configured with
--enable-hardcoded-path-in-tests since otherwise the execve just picks up
the system dynamic linker. */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
static int
do_test (int argc, char **argv)
{
if (argc == 2)
return 0;
char envname[] = "FOOBAR";
char *filename = program_invocation_name;
char *newargv[] = {filename, filename, NULL};
char *newenviron[] = {envname, NULL};
/* This was reported in Fedora:
https://bugzilla.redhat.com/show_bug.cgi?id=1414589
If one of the environment variables has no value, then the environment
traversal must skip and also advance to the next environment entry. The
bug in question would cause this test to hang in an infinite loop. */
int ret = execve (filename, newargv, newenviron);
if (ret != 0)
printf ("execve failed: %m");
/* We will reach here only if we fail execve. */
return 1;
}
#define TIMEOUT 3
#define TEST_FUNCTION_ARGV do_test
#include <support/test-driver.c>