[PATCH 2/4] sunrpc: Fix buffer overflow in clnt_create for "unix" (bug 22542)

[Florian Weimer]

---
 NEWS              |  4 +++-
 sunrpc/clnt_gen.c | 10 +++++++---
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/NEWS b/NEWS
index a957b19fdc..c1df8e1a0f 100644
--- a/NEWS
+++ b/NEWS
@@ -150,7 +150,9 @@ Changes to build and runtime requirements:
 
 Security related changes:
 
-  [Add security related changes here]
+  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)
-- 
2.34.1