Re: [PATCH 3/4] sunrpc: Test case for clnt_create "unix" buffer overflow (bug 22542)

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 14/01/2022 13:54, Florian Weimer via Libc-alpha wrote:
> From: Martin Sebor <msebor@redhat.com>
> 
> ---
>   sunrpc/Makefile       |  5 ++++-
>   sunrpc/tst-bug22542.c | 44 +++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 48 insertions(+), 1 deletion(-)
>   create mode 100644 sunrpc/tst-bug22542.c

LGTM.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

> 
> diff --git a/sunrpc/Makefile b/sunrpc/Makefile
> index 9a31fe48b9..183ef3dc55 100644
> --- a/sunrpc/Makefile
> +++ b/sunrpc/Makefile
> @@ -65,7 +65,8 @@ shared-only-routines = $(routines)
>   endif
>   
>   tests = tst-xdrmem tst-xdrmem2 test-rpcent tst-udp-error tst-udp-timeout \
> -  tst-udp-nonblocking
> +  tst-udp-nonblocking tst-bug22542
> +
>   xtests := tst-getmyaddr
>   
>   ifeq ($(have-thread-library),yes)
> @@ -110,6 +111,8 @@ $(objpfx)tst-udp-nonblocking: $(common-objpfx)linkobj/libc.so
>   $(objpfx)tst-udp-garbage: \
>     $(common-objpfx)linkobj/libc.so $(shared-thread-library)
>   
> +$(objpfx)tst-bug22542: $(common-objpfx)linkobj/libc.so
> +
>   else # !have-GLIBC_2.31
>   
>   routines = $(routines-for-nss)
> diff --git a/sunrpc/tst-bug22542.c b/sunrpc/tst-bug22542.c
> new file mode 100644
> index 0000000000..d6cd79787b
> --- /dev/null
> +++ b/sunrpc/tst-bug22542.c
> @@ -0,0 +1,44 @@
> +/* Test to verify that overlong hostname is rejected by clnt_create
> +   and doesn't cause a buffer overflow (bug  22542).
> +
> +   Copyright (C) 2022 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/>.  */
> +
> +#include <errno.h>
> +#include <rpc/clnt.h>
> +#include <string.h>
> +#include <support/check.h>
> +#include <sys/socket.h>
> +#include <sys/un.h>
> +
> +static int
> +do_test (void)
> +{
> +  /* Create an arbitrary hostname that's longer than fits in sun_path.  */
> +  char name [sizeof ((struct sockaddr_un*)0)->sun_path * 2];
> +  memset (name, 'x', sizeof name - 1);
> +  name [sizeof name - 1] = '\0';
> +
> +  errno = 0;
> +  CLIENT *clnt = clnt_create (name, 0, 0, "unix");
> +
> +  TEST_VERIFY (clnt == NULL);
> +  TEST_COMPARE (errno, EINVAL);
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>