From 46e7f36feb8ac85925dcb01367a405d44c2fe952 Mon Sep 17 00:00:00 2001
From: millert <millert@openbsd.org>
Date: Wed, 12 Apr 2017 15:23:08 +0000
Subject: [PATCH] Prevent inosused from wrapping when soft updates is enabled
 while scanning the used inode map.  The code as written assumes inosused is
 signed but this is no longer the case.  OK deraadt@

---
 sbin/fsck_ffs/pass1.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/sbin/fsck_ffs/pass1.c b/sbin/fsck_ffs/pass1.c
index 02bb8ad32a5..61d5431ecb8 100644
--- a/sbin/fsck_ffs/pass1.c
+++ b/sbin/fsck_ffs/pass1.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pass1.c,v 1.44 2017/04/10 08:19:12 fcambus Exp $	*/
+/*	$OpenBSD: pass1.c,v 1.45 2017/04/12 15:23:08 millert Exp $	*/
 /*	$NetBSD: pass1.c,v 1.16 1996/09/27 22:45:15 christos Exp $	*/
 
 /*
@@ -116,9 +116,14 @@ pass1(void)
 		 */
 		if (preen && usedsoftdep) {
 			cp = &cg_inosused(&cgrp)[(inosused - 1) / CHAR_BIT];
-			for ( ; inosused > 0; inosused -= CHAR_BIT, cp--) {
-				if (*cp == 0)
+			for ( ; inosused != 0; cp--) {
+				if (*cp == 0) {
+					if (inosused > CHAR_BIT)
+						inosused -= CHAR_BIT;
+					else
+						inosused = 0;
 					continue;
+				}
 				for (i = 1 << (CHAR_BIT - 1); i > 0; i >>= 1) {
 					if (*cp & i)
 						break;
-- 
2.20.1