From: Joerg Roedel jroedel@suse.de
[ 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 --- 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 7692bf7908e6c..143fcb8af38f4 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -701,7 +701,7 @@ 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: