glibc/sunrpc/tst-udp-error.c
Florian Weimer d42eed4a04 sunrpc: Avoid use-after-free read access in clntudp_call [BZ #21115]
After commit bc779a1a5b
(CVE-2016-4429: sunrpc: Do not use alloca in clntudp_call
[BZ #20112]), ancillary data is stored on the heap,
but it is accessed after it has been freed.

The test case must be run under a heap debugger such as valgrind
to observe the invalid access.  A malloc implementation which
immediately calls munmap on free would catch this bug as well.
2017-02-27 19:05:13 +01:00

63 lines
2.0 KiB
C

/* Check for use-after-free in clntudp_call (bug 21115).
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/>. */
#include <netinet/in.h>
#include <rpc/clnt.h>
#include <rpc/svc.h>
#include <support/check.h>
#include <support/namespace.h>
#include <support/xsocket.h>
#include <unistd.h>
static int
do_test (void)
{
support_become_root ();
support_enter_network_namespace ();
/* Obtain a likely-unused port number. */
struct sockaddr_in sin =
{
.sin_family = AF_INET,
.sin_addr.s_addr = htonl (INADDR_LOOPBACK),
};
{
int fd = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
xbind (fd, (struct sockaddr *) &sin, sizeof (sin));
socklen_t sinlen = sizeof (sin);
xgetsockname (fd, (struct sockaddr *) &sin, &sinlen);
/* Close the socket, so that we will receive an error below. */
close (fd);
}
int sock = RPC_ANYSOCK;
CLIENT *clnt = clntudp_create
(&sin, 1, 2, (struct timeval) { 1, 0 }, &sock);
TEST_VERIFY_EXIT (clnt != NULL);
TEST_VERIFY (clnt_call (clnt, 3,
(xdrproc_t) xdr_void, NULL,
(xdrproc_t) xdr_void, NULL,
((struct timeval) { 3, 0 }))
== RPC_CANTRECV);
clnt_destroy (clnt);
return 0;
}
#include <support/test-driver.c>