[LTP] [RFC PATCH 2/2] cve/cve-2018-1000001: Add Realpath Buffer Underflow test

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> ---
> NOTE: I didn't use TEST() macro due warning assignment makes integer
> from pointer without a cast. Am I blind not to see how to use it?

You are not, the TEST() macro supports only integer return values.

We may as well add a support for this, maybe just rename the TEST_RETURN
to tst_ret and add void* tst_ret_ptr. If we make the tst_ret to intptr_t
we may as well safely do something as:

	tst_ret_ptr = (void*)(tst_ret = (intptr_t) SCALL);

And we should rename TEST_ERRNO tst_errno as well just to keep it
consistent.

Or we can as well avoid this trickery by defining second TESTPTR() macro
that will use tst_ret_ptr instead.

> ---
>  testcases/cve/cve-2018-1000001.c | 66 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 testcases/cve/cve-2018-1000001.c
> 
> diff --git a/testcases/cve/cve-2018-1000001.c b/testcases/cve/cve-2018-1000001.c
> new file mode 100644
> index 000000000..ae41c786f
> --- /dev/null
> +++ b/testcases/cve/cve-2018-1000001.c
> @@ -0,0 +1,66 @@
> +/*
> + * Copyright (C) 2018 Petr Vorel <pvorel@suse.cz>
> + *
> + * This program is free software: you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program 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 General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "tst_test.h"
> +
> +#include <errno.h>
> +#include <stdlib.h>
> +
> +#define CHROOT_DIR "cve-2018-1000001"
> +
> +static void setup(void)
> +{
> +	SAFE_MKDIR(CHROOT_DIR, 0755);
> +	SAFE_CHROOT(CHROOT_DIR);
> +}
> +
> +static void run(unsigned int i)
> +{
> +	char *cwd;
> +
> +	int fail = 0;
> +
> +	errno = 0;
> +	if (!i) {
> +		tst_res(TINFO, "testing getcwd()");
> +		cwd = getcwd(NULL, 0);
> +	} else {
> +		tst_res(TINFO, "testing realpath()");
> +		cwd = realpath(".", NULL);
> +	}
> +
> +	if (errno != ENOENT) {
> +		tst_res(TFAIL | TERRNO, "returned unexpected errno");
> +		fail = 1;
> +	}
> +
> +	if (cwd != NULL) {
        ^
	No need for the NULL comparsion, can write just:

	if (cwd) {
> +		tst_res(TFAIL, "getcwd() not returned NULL path: '%s'", cwd);
                                ^
				getcwd()/realpath()
> +		fail = 1;
> +	}
> +
> +	if (!fail)
> +		tst_res(TPASS, "bug not reproduced");
> +}
> +
> +static struct tst_test test = {
> +	.test = run,
> +	.tcnt = 2,
> +	.setup = setup,
> +	.needs_root = 1,
> +	.needs_tmpdir = 1,
> +};

Other than the very minor nits this looks fine.

-- 
Cyril Hrubis
chrubis@suse.cz