From f4aa3a18a20d51575562520754aa376b3b08b2d0 Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Fri, 5 Feb 2016 20:22:51 -0500
Subject: [PATCH] Force certain "pljava" custom GUCs to be PGC_SUSET.

Future PL/Java versions will close CVE-2016-0766 by making these GUCs
PGC_SUSET.  This PostgreSQL change independently mitigates that PL/Java
vulnerability, helping sites that update PostgreSQL more frequently than
PL/Java.  Back-patch to 9.1 (all supported versions).

Upstream-Status: Backport

Signed-off-by: Noah Misch <noah@leadboat.com>
Index: postgresql-9.4.4/src/backend/utils/misc/guc.c
===================================================================
--- postgresql-9.4.4.orig/src/backend/utils/misc/guc.c	2015-06-10 03:29:38.000000000 +0800
+++ postgresql-9.4.4/src/backend/utils/misc/guc.c	2016-03-04 15:58:26.459266951 +0800
@@ -7072,6 +7072,17 @@
 		!process_shared_preload_libraries_in_progress)
 		elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
 
+	/*
+	 * Before pljava commit 398f3b876ed402bdaec8bc804f29e2be95c75139
+	 * (2015-12-15), two of that module's PGC_USERSET variables facilitated
+	 * trivial escalation to superuser privileges.  Restrict the variables to
+	 * protect sites that have yet to upgrade pljava.
+	 */
+	if (context == PGC_USERSET &&
+		(strcmp(name, "pljava.classpath") == 0 ||
+		 strcmp(name, "pljava.vmoptions") == 0))
+		context = PGC_SUSET;
+
 	gen = (struct config_generic *) guc_malloc(ERROR, sz);
 	memset(gen, 0, sz);