$NetBSD: patch-qemu-e1000-CVSE-2012-0029,v 1.1 2012/02/03 17:00:25 bouyer Exp $

Backported from:
From 3cf61880403b4e484539596a95937cc066243388 Mon Sep 17 00:00:00 2001
From: Ian Campbell <Ian.Campbell@citrix.com>
Date: Thu, 2 Feb 2012 13:47:06 +0000
Subject: [PATCH] e1000: bounds packet size against buffer size

Otherwise we can write beyond the buffer and corrupt memory.  This is tracked
as CVE-2012-0029.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

(Backported from qemu upstream 65f82df0d7a71ce1b10cd4c5ab08888d176ac840
 by Ian Campbell.)

Signed-off-by: Ian Campbell <Ian.Campbell@citrix.com>
(cherry picked from commit ebe37b2a3f844bad02dcc30d081f39eda06118f8)


--- ioemu/hw/e1000.c.orig	2009-08-06 14:56:34.000000000 +0200
+++ ioemu/hw/e1000.c	2012-02-03 14:51:56.000000000 +0100
@@ -397,6 +401,8 @@
             bytes = split_size;
             if (tp->size + bytes > msh)
                 bytes = msh - tp->size;
+
+	    bytes = MIN(sizeof(tp->data) - tp->size, bytes);
             cpu_physical_memory_read(addr, tp->data + tp->size, bytes);
             if ((sz = tp->size + bytes) >= hdr && tp->size < hdr)
                 memmove(tp->header, tp->data, hdr);
@@ -412,6 +418,7 @@
         // context descriptor TSE is not set, while data descriptor TSE is set
         DBGOUT(TXERR, "TCP segmentaion Error\n");
     } else {
+	split_size = MIN(sizeof(tp->data) - tp->size, split_size);
         cpu_physical_memory_read(addr, tp->data + tp->size, split_size);
         tp->size += split_size;
     }