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| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-04-25 19:01:09 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-08 07:22:57 +0200 |
| commit | 8f2b774cbf81603a8146fb2e2d92dc88001fafec (patch) | |
| tree | 1c8cd2977be4e0b90dd49bc85b4c975334986ece | |
| parent | 99678e9cf282353b9b2938c7271e551b34a76ac9 (diff) | |
| download | linux-stable-8f2b774cbf81603a8146fb2e2d92dc88001fafec.tar.gz linux-stable-8f2b774cbf81603a8146fb2e2d92dc88001fafec.tar.bz2 linux-stable-8f2b774cbf81603a8146fb2e2d92dc88001fafec.zip | |
KVM: lapic: Check for in-kernel LAPIC before deferencing apic pointer
commit b904cb8dff824b79233e82c078837627ebd52717 upstream.
...to avoid dereferencing a null pointer when querying the per-vCPU
timer advance.
Fixes: 39497d7660d98 ("KVM: lapic: Track lapic timer advance per vCPU")
Reported-by: syzbot+f7e65445a40d3e0e4ebf@syzkaller.appspotmail.com
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/lapic.c | 3 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 3 |
2 files changed, 2 insertions, 4 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 4ae142eea96a..3339697de6e5 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1504,9 +1504,6 @@ void wait_lapic_expire(struct kvm_vcpu *vcpu) u32 timer_advance_ns = apic->lapic_timer.timer_advance_ns; u64 guest_tsc, tsc_deadline, ns; - if (!lapic_in_kernel(vcpu)) - return; - if (apic->lapic_timer.expired_tscdeadline == 0) return; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 613dd3c89b94..3eeb7183fc09 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7886,7 +7886,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) } trace_kvm_entry(vcpu->vcpu_id); - if (vcpu->arch.apic->lapic_timer.timer_advance_ns) + if (lapic_in_kernel(vcpu) && + vcpu->arch.apic->lapic_timer.timer_advance_ns) wait_lapic_expire(vcpu); guest_enter_irqoff(); |