This is a note to let you know that I've just added the patch titled KVM: x86: Handle 32-bit wrap of EIP for EMULTYPE_SKIP with flat code seg to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-x86-handle-32-bit-wrap-of-eip-for-emultype_skip-.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ebdb52f41732c62c9316577c2fe2f010650cb804 Author: Sean Christopherson <seanjc@xxxxxxxxxx> Date: Tue Nov 2 17:15:29 2021 +0800 KVM: x86: Handle 32-bit wrap of EIP for EMULTYPE_SKIP with flat code seg [ Upstream commit 5e854864ee4384736f27a986633bae21731a4e4e ] Truncate the new EIP to a 32-bit value when handling EMULTYPE_SKIP as the decode phase does not truncate _eip. Wrapping the 32-bit boundary is legal if and only if CS is a flat code segment, but that check is implicitly handled in the form of limit checks in the decode phase. Opportunstically prepare for a future fix by storing the result of any truncation in "eip" instead of "_eip". Fixes: 1957aa63be53 ("KVM: VMX: Handle single-step #DB for EMULTYPE_SKIP on EPT misconfig") Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Message-Id: <093eabb1eab2965201c9b018373baf26ff256d85.1635842679.git.houwenlong93@xxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 33457b27e220b..6b76486702ded 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7999,7 +7999,12 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, * updating interruptibility state and injecting single-step #DBs. */ if (emulation_type & EMULTYPE_SKIP) { - kvm_rip_write(vcpu, ctxt->_eip); + if (ctxt->mode != X86EMUL_MODE_PROT64) + ctxt->eip = (u32)ctxt->_eip; + else + ctxt->eip = ctxt->_eip; + + kvm_rip_write(vcpu, ctxt->eip); if (ctxt->eflags & X86_EFLAGS_RF) kvm_set_rflags(vcpu, ctxt->eflags & ~X86_EFLAGS_RF); return 1;