From: Yinghai Lu <yinghai@kernel.org>
Date: Mon, 30 Mar 2009 18:50:28 +0000 (+0000)
Subject: x86: fix 64k corruption-check
X-Git-Tag: v2.6.29.1~12
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=393c20529ebe898fb975744ed0aad5bdd953f232;p=thirdparty%2Fkernel%2Fstable.git

x86: fix 64k corruption-check

upstream commit: 6d7942dc2a70a7e74c352107b150265602671588

Impact: fix boot crash

Need to exit early if the addr is far above 64k.

The crash got exposed by:

  78a8b35: x86: make e820_update_range() handle small range update

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: <stable@kernel.org>
LKML-Reference: <49BC2279.2030101@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

diff --git a/arch/x86/kernel/check.c b/arch/x86/kernel/check.c
index 2ac0ab71412a5..a7a50b24eb9e1 100644
--- a/arch/x86/kernel/check.c
+++ b/arch/x86/kernel/check.c
@@ -86,12 +86,12 @@ void __init setup_bios_corruption_check(void)
 		if (addr == 0)
 			break;
 
+		if (addr >= corruption_check_size)
+			break;
+
 		if ((addr + size) > corruption_check_size)
 			size = corruption_check_size - addr;
 
-		if (size == 0)
-			break;
-
 		e820_update_range(addr, size, E820_RAM, E820_RESERVED);
 		scan_areas[num_scan_areas].addr = addr;
 		scan_areas[num_scan_areas].size = size;