From 226b46770c82899b555986583294b049c6ec9b40 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Mon, 17 Jan 2022 10:21:34 +0100
Subject: [PATCH] CVE-2022-23219: Buffer overflow in sunrpc clnt_create for
 "unix" (bug 22542)

Processing an overlong pathname in the sunrpc clnt_create function
results in a stack-based buffer overflow.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
---
 NEWS              |  4 +++-
 sunrpc/clnt_gen.c | 10 +++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

#diff --git a/NEWS b/NEWS
#index ddd95a8329..38a9ddb2cf 100644
#--- a/NEWS
#+++ b/NEWS
#@@ -156,7 +156,9 @@ Changes to build and runtime requirements:
# 
# Security related changes:
# 
#-  [Add security related changes here]
#+  CVE-2022-23219: Passing an overlong file name to the clnt_create
#+  legacy function could result in a stack-based buffer overflow when
#+  using the "unix" protocol.  Reported by Martin Sebor.
# 
# The following bugs are resolved with this release:
# 
diff --git a/sunrpc/clnt_gen.c b/sunrpc/clnt_gen.c
index 13ced8994e..b44357cd88 100644
--- a/sunrpc/clnt_gen.c
+++ b/sunrpc/clnt_gen.c
@@ -57,9 +57,13 @@ clnt_create (const char *hostname, u_long prog, u_long vers,
 
   if (strcmp (proto, "unix") == 0)
     {
-      memset ((char *)&sun, 0, sizeof (sun));
-      sun.sun_family = AF_UNIX;
-      strcpy (sun.sun_path, hostname);
+      if (__sockaddr_un_set (&sun, hostname) < 0)
+	{
+	  struct rpc_createerr *ce = &get_rpc_createerr ();
+	  ce->cf_stat = RPC_SYSTEMERROR;
+	  ce->cf_error.re_errno = errno;
+	  return NULL;
+	}
       sock = RPC_ANYSOCK;
       client = clntunix_create (&sun, prog, vers, &sock, 0, 0);
       if (client == NULL)
-- 
2.27.0