[PATCH 5.19 160/717] KVM: x86/emulator: Fix handing of POP SS to correctly set interruptibility

Greg Kroah-Hartman
2022-10-22T07:45:51Z

From: Michal Luczaj <mhal@rbox.co>

commit 6aa5c47c351b22c21205c87977c84809cd015fcf upstream.

The emulator checks the wrong variable while setting the CPU
interruptibility state, the target segment is embedded in the instruction
opcode, not the ModR/M register. Fix the condition.

Signed-off-by: Michal Luczaj <mhal@rbox.co>
Fixes: a5457e7bcf9a ("KVM: emulate: POP SS triggers a MOV SS shadow too")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20220821215900.1419215-1-mhal@rbox.co
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kvm/emulate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1955,7 +1955,7 @@ static int em_pop_sreg(struct x86_emulat
if (rc != X86EMUL_CONTINUE)
return rc;

- if (ctxt->modrm_reg == VCPU_SREG_SS)
+ if (seg == VCPU_SREG_SS)
ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
if (ctxt->op_bytes > 2)
rsp_increment(ctxt, ctxt->op_bytes - 2);