The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 6fcee03df6a1a3101a77344be37bb85c6142d56c Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Date: Tue, 22 Mar 2022 19:24:42 +0200
Subject: [PATCH] KVM: x86: avoid loading a vCPU after .vm_destroy was called
This can cause various unexpected issues, since VM is partially
destroyed at that point.
For example when AVIC is enabled, this causes avic_vcpu_load to
access physical id page entry which is already freed by .vm_destroy.
Fixes: 8221c1370056 ("svm: Manage vcpu load/unload when enable AVIC")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Message-Id: <20220322172449.235575-2-mlevitsk@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 1abce22b14d7..ba4faeb32437 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11816,20 +11816,15 @@ static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
vcpu_put(vcpu);
}
-static void kvm_free_vcpus(struct kvm *kvm)
+static void kvm_unload_vcpu_mmus(struct kvm *kvm)
{
unsigned long i;
struct kvm_vcpu *vcpu;
- /*
- * Unpin any mmu pages first.
- */
kvm_for_each_vcpu(i, vcpu, kvm) {
kvm_clear_async_pf_completion_queue(vcpu);
kvm_unload_vcpu_mmu(vcpu);
}
-
- kvm_destroy_vcpus(kvm);
}
void kvm_arch_sync_events(struct kvm *kvm)
@@ -11935,11 +11930,12 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
__x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, 0, 0);
mutex_unlock(&kvm->slots_lock);
}
+ kvm_unload_vcpu_mmus(kvm);
static_call_cond(kvm_x86_vm_destroy)(kvm);
kvm_free_msr_filter(srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1));
kvm_pic_destroy(kvm);
kvm_ioapic_destroy(kvm);
- kvm_free_vcpus(kvm);
+ kvm_destroy_vcpus(kvm);
kvfree(rcu_dereference_check(kvm->arch.apic_map, 1));
kfree(srcu_dereference_check(kvm->arch.pmu_event_filter, &kvm->srcu, 1));
kvm_mmu_uninit_vm(kvm);
