From 958d4b4dce1f2efe99ea12e57d7fb93314505631 Mon Sep 17 00:00:00 2001
From: Joerg Roedel <jroedel@suse.de>
Date: Thu, 21 Oct 2021 10:08:32 +0200
Subject: [PATCH] x86/sev: Fix stack type check in vc_switch_off_ist()
Git-commit: 5681981fb788281b09a4ea14d310d30b2bd89132
Patch-mainline: v5.16-rc1
References: stable-5.14.19
[ Upstream commit 5681981fb788281b09a4ea14d310d30b2bd89132 ]
The value of STACK_TYPE_EXCEPTION_LAST points to the last _valid_
exception stack. Reflect that in the check done in the
vc_switch_off_ist() function.
Fixes: a13644f3a53de ("x86/entry/64: Add entry code for #VC handler")
Reported-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211021080833.30875-2-joro@8bytes.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/x86/kernel/traps.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index cc6de3a01293..5b1984d46822 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -743,7 +743,7 @@ asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *r
stack = (unsigned long *)sp;
if (!get_stack_info_noinstr(stack, current, &info) || info.type == STACK_TYPE_ENTRY ||
- info.type >= STACK_TYPE_EXCEPTION_LAST)
+ info.type > STACK_TYPE_EXCEPTION_LAST)
sp = __this_cpu_ist_top_va(VC2);
sync:
--
2.26.2