commit f545ad4928fa1f27a3075265182b38a4f939a5f7

Author: Florian Weimer <fweimer@redhat.com>

Date:   Mon Jan 17 10:21:34 2022 +0100

    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>

diff --git a/sunrpc/Makefile b/sunrpc/Makefile

index 2f8f0597c99e117f..5f7087aee494cc2e 100644

--- a/sunrpc/Makefile

+++ b/sunrpc/Makefile

@@ -95,7 +95,7 @@ others += rpcgen

 endif

 tests = tst-xdrmem tst-xdrmem2 test-rpcent tst-udp-error tst-udp-timeout \

-  tst-udp-nonblocking tst-bug22542

+  tst-udp-nonblocking tst-bug22542 tst-bug28768

 xtests := tst-getmyaddr

diff --git a/sunrpc/svc_unix.c b/sunrpc/svc_unix.c

index c2c076aa87f0a2ad..8fac2b35da1d38a5 100644

--- a/sunrpc/svc_unix.c

+++ b/sunrpc/svc_unix.c

@@ -154,7 +154,10 @@ svcunix_create (int sock, u_int sendsize, u_int recvsize, char *path)

   SVCXPRT *xprt;

   struct unix_rendezvous *r;

   struct sockaddr_un addr;

-  socklen_t len = sizeof (struct sockaddr_in);

+  socklen_t len = sizeof (addr);

+

+  if (__sockaddr_un_set (&addr, path) < 0)

+    return NULL;

   if (sock == RPC_ANYSOCK)

     {

@@ -165,12 +168,6 @@ svcunix_create (int sock, u_int sendsize, u_int recvsize, char *path)

 	}

       madesock = TRUE;

     }

-  memset (&addr, '\0', sizeof (addr));

-  addr.sun_family = AF_UNIX;

-  len = strlen (path) + 1;

-  memcpy (addr.sun_path, path, len);

-  len += sizeof (addr.sun_family);

-

   __bind (sock, (struct sockaddr *) &addr, len);

   if (__getsockname (sock, (struct sockaddr *) &addr, &len) != 0

diff --git a/sunrpc/tst-bug28768.c b/sunrpc/tst-bug28768.c

new file mode 100644

index 0000000000000000..35a4b7b0b3d34350

--- /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>