CVE-2022-23218: Buffer overflow in sunrpc svcunix_create (bug 28768)

The sunrpc function svcunix_create suffers from a stack-based buffer
overflow with overlong pathname arguments.

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

1 files changed, 42 insertions, 0 deletions

diff --git a/sunrpc/tst-bug28768.c b/sunrpc/tst-bug28768.c
new file mode 100644
index 0000000000..35a4b7b0b3
--- /dev/null
+++ b/sunrpc/tst-bug28768.c
@@ -0,0 +1,42 @@
+/* Test to verify that long path is rejected by svcunix_create (bug 28768).
+   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/svc.h>
+#include <shlib-compat.h>
+#include <string.h>
+#include <support/check.h>
+
+/* svcunix_create does not have a default version in linkobj/libc.so.  */
+compat_symbol_reference (libc, svcunix_create, svcunix_create, GLIBC_2_1);
+
+static int
+do_test (void)
+{
+  char pathname[109];
+  memset (pathname, 'x', sizeof (pathname));
+  pathname[sizeof (pathname) - 1] = '\0';
+
+  errno = 0;
+  TEST_VERIFY (svcunix_create (RPC_ANYSOCK, 4096, 4096, pathname) == NULL);
+  TEST_COMPARE (errno, EINVAL);
+
+  return 0;
+}
+
+#include <support/test-driver.c>