commit 1081f1d3dd7c84ba3416b5198d47a4df2b70185d
Author: Martin Sebor <msebor@redhat.com>
Date:   Mon Jan 17 10:21:34 2022 +0100

    sunrpc: Test case for clnt_create "unix" buffer overflow (bug 22542)
    
    Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
    (cherry picked from commit ef972a4c50014a16132b5c75571cfb6b30bef136)

diff --git a/sunrpc/Makefile b/sunrpc/Makefile
index 7e5bbfd951b1e835..a4281b18d04c78e9 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 0000000000000000..d6cd79787bdef21d
--- /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>