rpms/kvm/F-9 kvm-int13.patch,NONE,1.1 kvm.spec,1.62,1.63
Glauber Costa
glommer at fedoraproject.org
Tue Dec 2 14:23:53 UTC 2008
Author: glommer
Update of /cvs/pkgs/rpms/kvm/F-9
In directory cvs1.fedora.phx.redhat.com:/tmp/cvs-serv22576
Modified Files:
kvm.spec
Added Files:
kvm-int13.patch
Log Message:
Properly set flags for interrupt return #464304
kvm-int13.patch:
--- NEW FILE kvm-int13.patch ---
>From c7ad3762330b685f523b1be1f0fc3caa8d3e29c6 Mon Sep 17 00:00:00 2001
From: Glauber Costa <glommer at redhat.com>
Date: Mon, 1 Dec 2008 14:30:22 -0500
Subject: [PATCH] extboot: properly set int 0x13 return value
Callers of int 0x13 usually rely on the carry flag being
clear/set to indicate the status of the interrupt execution.
However, our current code clear or set the flags register,
which is totally useless. Whichever value it has, will
be overwritten by the flags value _before_ the interrupt, due to
the iret instruction.
This fixes a bug that prevents slackware (and possibly win2k, untested)
to boot.
Signed-off-by: Glauber Costa <glommer at redhat.com>
---
extboot/extboot.S | 52 ++++++++++++++++++++++++++--------------------------
1 files changed, 26 insertions(+), 26 deletions(-)
diff --git a/extboot/extboot.S b/extboot/extboot.S
index 2630abb..e3d1adf 100644
--- a/extboot/extboot.S
+++ b/extboot/extboot.S
@@ -99,24 +99,24 @@ int19_handler:
#define FLAGS_CF 0x01
-.macro clc
- push %ax
- pushf
- pop %ax
- and $(~FLAGS_CF), %ax
- push %ax
- popf
- pop %ax
+/* The two macro below clear/set the carry flag to indicate the status
+ * of the interrupt execution. It is not enough to issue a clc/stc instruction,
+ * since the value of the flags register will be overwritten by whatever is
+ * in the stack frame
+ */
+.macro clc_stack
+ push %bp
+ mov %sp, %bp
+ /* 8 = 2 (bp, just pushed) + 2 (ip) + 3 (real mode interrupt frame) */
+ and $(~FLAGS_CF), 8(%bp)
+ pop %bp
.endm
-.macro stc
- push %ax
- pushf
- pop %ax
- or $(FLAGS_CF), %ax
- push %ax
- popf
- pop %ax
+.macro stc_stack
+ push %bp
+ /* 8 = 2 (bp, just pushed) + 2 (ip) + 3 (real mode interrupt frame) */
+ or $(FLAGS_CF), 8(%bp)
+ pop %bp
.endm
/* we clobber %bx */
@@ -292,7 +292,7 @@ mul32: /* lo, hi, lo, hi */
disk_reset:
movb $0, %ah
- clc
+ clc_stack
ret
/* this really should be a function, not a macro but i'm lazy */
@@ -395,7 +395,7 @@ disk_reset:
pop %ax
mov $0, %ah
- clc
+ clc_stack
ret
.endm
@@ -454,12 +454,12 @@ read_disk_drive_parameters:
pop %bx
/* do this last since it's the most sensitive */
- clc
+ clc_stack
ret
alternate_disk_reset:
movb $0, %ah
- clc
+ clc_stack
ret
read_disk_drive_size:
@@ -498,21 +498,21 @@ read_disk_drive_size:
freea
pop %bx
- clc
+ clc_stack
ret
check_if_extensions_present:
mov $0x30, %ah
mov $0xAA55, %bx
mov $0x07, %cx
- clc
+ clc_stack
ret
.macro extended_read_write_sectors cmd
cmpb $10, 0(%si)
jg 1f
mov $1, %ah
- stc
+ stc_stack
ret
1:
push %ax
@@ -544,7 +544,7 @@ check_if_extensions_present:
pop %ax
mov $0, %ah
- clc
+ clc_stack
ret
.endm
@@ -612,12 +612,12 @@ get_extended_drive_parameters:
pop %ax
mov $0, %ah
- clc
+ clc_stack
ret
terminate_disk_emulation:
mov $1, %ah
- stc
+ stc_stack
ret
int13_handler:
--
1.5.6.5
Index: kvm.spec
===================================================================
RCS file: /cvs/pkgs/rpms/kvm/F-9/kvm.spec,v
retrieving revision 1.62
retrieving revision 1.63
diff -u -r1.62 -r1.63
--- kvm.spec 11 Nov 2008 15:49:47 -0000 1.62
+++ kvm.spec 2 Dec 2008 14:23:22 -0000 1.63
@@ -1,7 +1,7 @@
Summary: Kernel-based Virtual Machine
Name: kvm
Version: 65
-Release: 11%{?dist}
+Release: 13%{?dist}
License: GPLv2+ and LGPLv2+
Group: Development/Tools
URL: http://%{name}.sf.net
@@ -20,6 +20,7 @@
Patch10: %{name}-acpi-do-not-ovflw.patch
Patch11: %{name}-sysenter32.patch
Patch12: %{name}-cirrus-cve-2008-4539.patch
+Patch13: %{name}-int13.patch
# patches from upstream qemu
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
BuildRequires: SDL-devel
@@ -61,6 +62,7 @@
%patch10 -p1
%patch11 -p1
%patch12 -p1
+%patch13 -p1
%build
# we need to install the data bits in a different path
@@ -115,6 +117,9 @@
%{_sysconfdir}/sysconfig/modules/%{name}.modules
%changelog
+* Tue Dec 02 2008 Glauber Costa <gcosta at redhat.com> - 65-12.fc9
+- Properly set flags for interrupt return #464304
+
* Tue Nov 11 2008 Glauber Costa <gcosta at redhat.com> - 65-11.fc9
- Fix CVE-2008-4539 #448525
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