File clntudp-call-alloca.patch of Package glibc.i686

2016-05-23  Florian Weimer  <fweimer@redhat.com>

	CVE-2016-4429
	[BZ #20112]
	* sunrpc/clnt_udp.c (clntudp_call): Use malloc/free for the error
	payload.

Index: glibc-2.22/sunrpc/clnt_udp.c
===================================================================
--- glibc-2.22.orig/sunrpc/clnt_udp.c
+++ glibc-2.22/sunrpc/clnt_udp.c
@@ -423,9 +423,15 @@ send_again:
 	  struct sock_extended_err *e;
 	  struct sockaddr_in err_addr;
 	  struct iovec iov;
-	  char *cbuf = (char *) alloca (outlen + 256);
+	  char *cbuf = malloc (outlen + 256);
 	  int ret;
 
+	  if (cbuf == NULL)
+	    {
+	      cu->cu_error.re_errno = errno;
+	      return (cu->cu_error.re_status = RPC_CANTRECV);
+	    }
+
 	  iov.iov_base = cbuf + 256;
 	  iov.iov_len = outlen;
 	  msg.msg_name = (void *) &err_addr;
@@ -450,10 +456,12 @@ send_again:
 		 cmsg = CMSG_NXTHDR (&msg, cmsg))
 	      if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
 		{
+		  free (cbuf);
 		  e = (struct sock_extended_err *) CMSG_DATA(cmsg);
 		  cu->cu_error.re_errno = e->ee_errno;
 		  return (cu->cu_error.re_status = RPC_CANTRECV);
 		}
+	  free (cbuf);
 	}
 #endif
       do