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| author | Andy Honig <ahonig@google.com> | 2013-11-20 22:23:22 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-29 17:10:42 +0400 |
| commit | 777f8f3bcde8dc29bac9ab7e4e94dd84887ba50d (patch) | |
| tree | 917a6209db6b2bc01b75692513a57bf5efa3c165 /arch/x86/kvm/lapic.h | |
| parent | 4b9c8e9bd1f5c549fb581f7edae250d4d9ebc922 (diff) | |
| download | linux-777f8f3bcde8dc29bac9ab7e4e94dd84887ba50d.tar.xz | |
KVM: x86: Convert vapic synchronization to _cached functions (CVE-2013-6368)
commit fda4e2e85589191b123d31cdc21fd33ee70f50fd upstream.
In kvm_lapic_sync_from_vapic and kvm_lapic_sync_to_vapic there is the
potential to corrupt kernel memory if userspace provides an address that
is at the end of a page. This patches concerts those functions to use
kvm_write_guest_cached and kvm_read_guest_cached. It also checks the
vapic_address specified by userspace during ioctl processing and returns
an error to userspace if the address is not a valid GPA.
This is generally not guest triggerable, because the required write is
done by firmware that runs before the guest. Also, it only affects AMD
processors and oldish Intel that do not have the FlexPriority feature
(unless you disable FlexPriority, of course; then newer processors are
also affected).
Fixes: b93463aa59d6 ('KVM: Accelerated apic support')
Reported-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Honig <ahonig@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[ lizf: backported to 3.4: based on Paolo's backport hints for <3.10 ]
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kvm/lapic.h')
| -rw-r--r-- | arch/x86/kvm/lapic.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 6f4ce2575d09..6aec0714398e 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -15,7 +15,7 @@ struct kvm_lapic { bool irr_pending; void *regs; gpa_t vapic_addr; - struct page *vapic_page; + struct gfn_to_hva_cache vapic_cache; }; int kvm_create_lapic(struct kvm_vcpu *vcpu); void kvm_free_lapic(struct kvm_vcpu *vcpu); @@ -46,7 +46,7 @@ int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu); u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu); void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data); -void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr); +int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr); void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu); void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu); |