This is a note to let you know that I've just added the patch titled KVM: x86: Inject #GP if WRMSR sets reserved bits in APIC Self-IPI to the 5.10-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-inject-gp-if-wrmsr-sets-reserved-bits-in-apic-self-ipi.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ba5838abb05334e4abfdff1490585c7f365e0424 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc@xxxxxxxxxx> Date: Sat, 7 Jan 2023 01:10:20 +0000 Subject: KVM: x86: Inject #GP if WRMSR sets reserved bits in APIC Self-IPI From: Sean Christopherson <seanjc@xxxxxxxxxx> commit ba5838abb05334e4abfdff1490585c7f365e0424 upstream. Inject a #GP if the guest attempts to set reserved bits in the x2APIC-only Self-IPI register. Bits 7:0 hold the vector, all other bits are reserved. Reported-by: Marc Orr <marcorr@xxxxxxxxxx> Cc: Ben Gardon <bgardon@xxxxxxxxxx> Cc: Venkatesh Srinivas <venkateshs@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230107011025.565472-2-seanjc@xxxxxxxxxx Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kvm/lapic.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2115,10 +2115,14 @@ int kvm_lapic_reg_write(struct kvm_lapic break; case APIC_SELF_IPI: - if (apic_x2apic_mode(apic)) - kvm_apic_send_ipi(apic, APIC_DEST_SELF | (val & APIC_VECTOR_MASK), 0); - else + /* + * Self-IPI exists only when x2APIC is enabled. Bits 7:0 hold + * the vector, everything else is reserved. + */ + if (!apic_x2apic_mode(apic) || (val & ~APIC_VECTOR_MASK)) ret = 1; + else + kvm_apic_send_ipi(apic, APIC_DEST_SELF | val, 0); break; default: ret = 1; Patches currently in stable-queue which might be from seanjc@xxxxxxxxxx are queue-5.10/x86-virt-force-gif-1-prior-to-disabling-svm-for-reboot-flows.patch queue-5.10/crypto-ccp-use-the-stack-for-small-sev-command-buffe.patch queue-5.10/kvm-x86-inject-gp-if-wrmsr-sets-reserved-bits-in-apic-self-ipi.patch queue-5.10/x86-reboot-disable-svm-not-just-vmx-when-stopping-cpus.patch queue-5.10/x86-reboot-disable-virtualization-in-an-emergency-if-svm-is-supported.patch queue-5.10/x86-crash-disable-virt-in-core-nmi-crash-handler-to-avoid-double-shootdown.patch queue-5.10/kvm-destroy-target-device-if-coalesced-mmio-unregistration-fails.patch queue-5.10/crypto-ccp-use-the-stack-and-common-buffer-for-statu.patch