2021-10-21 08:11:19

by Joerg Roedel

Subject: [PATCH 1/2] x86/sev: Fix stack type check in vc_switch_off_ist()

From: Joerg Roedel <[email protected]>

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.

Reported-by: Tom Lendacky <[email protected]>
Fixes: a13644f3a53de ("x86/entry/64: Add entry code for #VC handler")
Signed-off-by: Joerg Roedel <[email protected]>
---
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 a58800973aed..f516f2b4797e 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -709,7 +709,7 @@ 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:
--
2.33.1

2021-10-21 17:05:46

by tip-bot2 for Alexey Makhalov

Subject: [tip: x86/sev] x86/sev: Fix stack type check in vc_switch_off_ist()

The following commit has been merged into the x86/sev branch of tip:

Commit-ID: 5681981fb788281b09a4ea14d310d30b2bd89132
Gitweb: https://git.kernel.org/tip/5681981fb788281b09a4ea14d310d30b2bd89132
Author: Joerg Roedel <[email protected]>
AuthorDate: Thu, 21 Oct 2021 10:08:32 +02:00
Committer: Borislav Petkov <[email protected]>
CommitterDate: Thu, 21 Oct 2021 18:24:44 +02:00

x86/sev: Fix stack type check in vc_switch_off_ist()

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 <[email protected]>
Signed-off-by: Joerg Roedel <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
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 a588009..f516f2b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -709,7 +709,7 @@ 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: