From: Coleman Dietsch dietschc@csp.edu
commit af735db31285fa699384c649be72a9f32ecbb665 upstream.
Add a check for existing xen timers before initializing a new one.
Currently kvm_xen_init_timer() is called on every KVM_XEN_VCPU_ATTR_TYPE_TIMER, which is causing the following ODEBUG crash when vcpu->arch.xen.timer is already set.
ODEBUG: init active (active state 0) object type: hrtimer hint: xen_timer_callbac0 RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502 Call Trace: __debug_object_init debug_hrtimer_init debug_init hrtimer_init kvm_xen_init_timer kvm_xen_vcpu_set_attr kvm_arch_vcpu_ioctl kvm_vcpu_ioctl vfs_ioctl
Fixes: 536395260582 ("KVM: x86/xen: handle PV timers oneshot mode") Cc: stable@vger.kernel.org Link: https://syzkaller.appspot.com/bug?id=8234a9dfd3aafbf092cc5a7cd9842e3ebc45fc4... Reported-by: syzbot+e54f930ed78eb0f85281@syzkaller.appspotmail.com Signed-off-by: Coleman Dietsch dietschc@csp.edu Reviewed-by: Sean Christopherson seanjc@google.com Message-Id: 20220808190607.323899-2-dietschc@csp.edu Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/xen.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -713,7 +713,9 @@ int kvm_xen_vcpu_set_attr(struct kvm_vcp break; } vcpu->arch.xen.timer_virq = data->u.timer.port; - kvm_xen_init_timer(vcpu); + + if (!vcpu->arch.xen.timer.function) + kvm_xen_init_timer(vcpu);
/* Restart the timer if it's set */ if (data->u.timer.expires_ns)