From c0019a8215949ca0b9de18b6c772dc0e8ccb334d Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Tue, 2 Oct 2007 11:17:36 -0700
Subject: [PATCH] bootsect.inc: make sure the $PnP header can fit inside the
 segment

Terminate the search as soon as the $PnP header would fall outside the
segment, not just the $PnP signature itself.
---
 bootsect.inc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bootsect.inc b/bootsect.inc
index 6989956..715100a 100644
--- a/bootsect.inc
+++ b/bootsect.inc
@@ -150,8 +150,8 @@ replace_bootstrap:
 		cmp dword [fs:bx], "$PnP"
 		jz .foundpnp
 		inc bx
-		cmp bx,-3		; Don't get a segment overflow error!
-		jb .findpnp
+		cmp bx,-21h		; Don't get a segment overflow error!
+		jbe .findpnp
 		jmp .donepnp		; No $PnP header found
 .foundpnp:
 		movzx cx,byte [fs:bx+5]	; Size of $PnP header
-- 
2.7.4