linux-kernel - [PATCH 1/3] xen, pvh: fix unbootable VMs (PVH + KASAN

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240802154253.482658-1-adobriyan@gmail.com>
Date: Fri,  2 Aug 2024 18:42:51 +0300
From: Alexey Dobriyan <adobriyan@...il.com>
To: jgross@...e.com,
	boris.ostrovsky@...cle.com,
	tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de,
	dave.hansen@...ux.intel.com
Cc: adobriyan@...il.com,
	linux-kernel@...r.kernel.org,
	x86@...nel.org,
	hpa@...or.com
Subject: [PATCH 1/3] xen, pvh: fix unbootable VMs (PVH + KASAN - AMD_MEM_ENCRYPT)

Uninstrument arch/x86/platform/pvh/enlighten.c: KASAN has not been setup
_this_ early in the boot process.

Steps to reproduce:

	make allnoconfig
	make sure CONFIG_AMD_MEM_ENCRYPT is disabled
		AMD_MEM_ENCRYPT independently uninstruments lib/string.o
		so PVH boot code calls into uninstrumented memset() and
		memcmp() which can make the bug disappear depending on
		the compiler.
	enable CONFIG_PVH
	enable CONFIG_KASAN
	enable serial console
		this is fun exercise if you never done it from nothing :^)

	make

	qemu-system-x86_64	\
		-enable-kvm	\
		-cpu host	\
		-smp cpus=1	\
		-m 4096		\
		-serial stdio	\
		-kernel vmlinux \
		-append 'console=ttyS0 ignore_loglevel'

Messages on serial console will easily tell OK kernel from unbootable
kernel. In bad case qemu hangs in an infinite loop stroboscoping
"SeaBIOS" message.

Signed-off-by: Alexey Dobriyan <adobriyan@...il.com>
Acked-by: Juergen Gross <jgross@...e.com>
---
 arch/x86/platform/pvh/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/platform/pvh/Makefile b/arch/x86/platform/pvh/Makefile
index 5dec5067c9fb..c43fb7964dc4 100644
--- a/arch/x86/platform/pvh/Makefile
+++ b/arch/x86/platform/pvh/Makefile
@@ -1,5 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 OBJECT_FILES_NON_STANDARD_head.o := y
+KASAN_SANITIZE := n
 
 obj-$(CONFIG_PVH) += enlighten.o
 obj-$(CONFIG_PVH) += head.o
-- 
2.45.0