syslinux/syslinux-fix-menu-memory-clobber.patch
2007-10-03 17:19:46 +00:00

26 lines
822 B
Diff

From: H. Peter Anvin <hpa@zytor.com>
Date: Fri, 21 Sep 2007 23:22:58 +0000 (-0700)
Subject: comboot: fix memory overwrite bug
X-Git-Tag: syslinux-3.52-pre9~2
X-Git-Url: http://git.kernel.org/?p=boot%2Fsyslinux%2Fsyslinux.git;a=commitdiff_plain;h=426d986dbc77abf2247b08c44c18bf9a478c2e8e
comboot: fix memory overwrite bug
Fix memory overwrite bug, specifically, the use of BP after it might
have gotten clobbered. Since at the point of use, BP is supposed to
be == SP, we can just add "mov bp,sp".
---
diff --git a/comboot.inc b/comboot.inc
index 3c9df5f..ffc9425 100644
--- a/comboot.inc
+++ b/comboot.inc
@@ -187,6 +187,7 @@ comboot_int21: cli
clc
call ax ; Call the invoked function
comboot_resume:
+ mov bp,sp ; In case the function clobbers BP
setc P_FLAGSL ; Propagate CF->error
popad
pop gs