This is a note to let you know that I've just added the patch titled
KVM: x86: cleanup the page tracking SRCU instance
to the 4.9-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-cleanup-the-page-tracking-srcu-instance.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2beb6dad2e8f95d710159d5befb390e4f62ab5cf Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Date: Mon, 27 Mar 2017 17:53:50 +0200
Subject: KVM: x86: cleanup the page tracking SRCU instance
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
commit 2beb6dad2e8f95d710159d5befb390e4f62ab5cf upstream.
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 <dvyukov@xxxxxxxxxx>
Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Fixes: 0eb05bf290cfe8610d9680b49abef37febd1c38a
Reviewed-by: Xiao Guangrong <xiaoguangrong.eric@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_page_track.h | 1 +
arch/x86/kvm/page_track.c | 8 ++++++++
arch/x86/kvm/x86.c | 1 +
3 files changed, 10 insertions(+)
--- a/arch/x86/include/asm/kvm_page_track.h
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -35,6 +35,7 @@ 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);
--- a/arch/x86/kvm/page_track.c
+++ b/arch/x86/kvm/page_track.c
@@ -156,6 +156,14 @@ bool kvm_page_track_is_active(struct kvm
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;
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7976,6 +7976,7 @@ 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,
Patches currently in stable-queue which might be from pbonzini@xxxxxxxxxx are
queue-4.9/kvm-x86-cleanup-the-page-tracking-srcu-instance.patch
queue-4.9/kvm-nvmx-fix-nested-vpid-vmx-exec-control.patch