[PATCH 5.15 123/530] KVM: x86/emulator: Fix handing of POP SS to correctly set interruptibility

[Greg Kroah-Hartman]

From: Michal Luczaj <mhal@xxxxxxx>

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@xxxxxxx>
Fixes: a5457e7bcf9a ("KVM: emulate: POP SS triggers a MOV SS shadow too")
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/all/20220821215900.1419215-1-mhal@xxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 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
@@ -1936,7 +1936,7 @@ 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);