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@

diff --git a/sbin/fsck_ffs/pass1.c b/sbin/fsck_ffs/pass1.c
index 02bb8ad..61d5431 100644 (file)
--- 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;