From: tedu <tedu@openbsd.org>
Date: Fri, 29 Jul 2016 20:44:40 +0000 (+0000)
Subject: add a check that the arguments to isavail don't overflow.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=5e38141c55bce6ceeaf7c96a4314e752c291a198;p=openbsd

add a check that the arguments to isavail don't overflow.
callers should probably check too, but checking here won't hurt.
possible panic reported by tim newsham.
ok kettenis
---

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index 50504646028..254dd4da146 100644
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_map.c,v 1.217 2016/06/17 10:48:25 dlg Exp $	*/
+/*	$OpenBSD: uvm_map.c,v 1.218 2016/07/29 20:44:40 tedu Exp $	*/
 /*	$NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $	*/
 
 /*
@@ -771,6 +771,9 @@ uvm_map_isavail(struct vm_map *map, struct uvm_addr_state *uaddr,
 	struct uvm_map_addr *atree;
 	struct vm_map_entry *i, *i_end;
 
+	if (addr + sz < addr)
+		return 0;
+
 	/*
 	 * Kernel memory above uvm_maxkaddr is considered unavailable.
 	 */