KVM: x86: cleanup the page tracking SRCU instance

SRCU uses a delayed work item.  Skip cleaning it up, and
the result is use-after-free in the work item callbacks.

Reported-by: Dmitry Vyukov <[email protected]>
Suggested-by: Dmitry Vyukov <[email protected]>
Cc: [email protected]
Fixes: 0eb05bf290cfe8610d9680b49abef37febd1c38a
Reviewed-by: Xiao Guangrong <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
index d74747b031ecd2e20dcf437944195a37e7c6bb3b..c4eda791f877b6c67808546ce072da07b9bb8002 100644 (file)
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -46,6 +46,7 @@ struct kvm_page_track_notifier_node {
 };
 
 void kvm_page_track_init(struct kvm *kvm);
+void kvm_page_track_cleanup(struct kvm *kvm);
 
 void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
                                 struct kvm_memory_slot *dont);

diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c
index 37942e419c32e599a4ba05d3b75a77680f0065d9..60168cdd05463e2e18c993e20dfdeed7986808ce 100644 (file)
--- a/arch/x86/kvm/page_track.c
+++ b/arch/x86/kvm/page_track.c
@@ -160,6 +160,14 @@ bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn,
        return !!ACCESS_ONCE(slot->arch.gfn_track[mode][index]);
 }
 
+void kvm_page_track_cleanup(struct kvm *kvm)
+{
+       struct kvm_page_track_notifier_head *head;
+
+       head = &kvm->arch.track_notifier_head;
+       cleanup_srcu_struct(&head->track_srcu);
+}
+
 void kvm_page_track_init(struct kvm *kvm)
 {
        struct kvm_page_track_notifier_head *head;

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 64697fe475c3cb0b005ee098d5e37974c646d53a..ccbd45ecd41a3fa5c850cf924cccbb2723aecc92 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8158,6 +8158,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
        kvm_free_vcpus(kvm);
        kvfree(rcu_dereference_check(kvm->arch.apic_map, 1));
        kvm_mmu_uninit_vm(kvm);
+       kvm_page_track_cleanup(kvm);
 }
 
 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,