From 0b52217d645e3457194d2514f3f52da8c90f6e4b Mon Sep 17 00:00:00 2001
From: hpa <hpa>
Date: Sat, 24 Jan 2004 21:12:20 +0000
Subject: [PATCH] Fail if C/H/S geometry is wrong.  This is necessary for
 things that probe for geometry.

---
 memdisk/memdisk.asm | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/memdisk/memdisk.asm b/memdisk/memdisk.asm
index 1f18ae7..053fa41 100644
--- a/memdisk/memdisk.asm
+++ b/memdisk/memdisk.asm
@@ -308,8 +308,12 @@ setup_regs:
 		movzx ebx,cl		; Sector number
 		and bl,3Fh
 		dec ebx			; Sector number is 1-based
+		cmp bx,[Sectors]
+		jae .overrun
 		movzx edi,P_DH		; Head number
 		movzx eax,word [Heads]
+		cmp di,ax
+		jae .overrun
 		shr cl,6
 		xchg cl,ch		; Now (E)CX <- cylinder number
 		mul ecx			; eax <- Heads*cyl# (edx <- 0)
-- 
2.7.4