On 14/06/21 13:38, Vitaly Kuznetsov wrote:
Hyper-V context is allocated dynamically when Hyper-V features are enabled on a vCPU but svm_hv_update_vp_id() is called unconditionally from svm_vcpu_run(), this leads to dereferencing to_hv_vcpu(vcpu) which can be NULL. Use kvm_hv_get_vpindex() wrapper to avoid the problem. Fixes: 4ba0d72aaa32 ("KVM: SVM: hyper-v: Direct Virtual Flush support") Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- - The patch introducing the issue is currently in kvm/queue. --- arch/x86/kvm/svm/svm_onhyperv.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h index ce23149670ea..9b9a55abc29f 100644 --- a/arch/x86/kvm/svm/svm_onhyperv.h +++ b/arch/x86/kvm/svm/svm_onhyperv.h @@ -99,9 +99,10 @@ static inline void svm_hv_update_vp_id(struct vmcb *vmcb, { struct hv_enlightenments *hve = (struct hv_enlightenments *)vmcb->control.reserved_sw; + u32 vp_index = kvm_hv_get_vpindex(vcpu);- if (hve->hv_vp_id != to_hv_vcpu(vcpu)->vp_index) {- hve->hv_vp_id = to_hv_vcpu(vcpu)->vp_index; + if (hve->hv_vp_id != vp_index) { + hve->hv_vp_id = vp_index; vmcb_mark_dirty(vmcb, VMCB_HV_NESTED_ENLIGHTENMENTS); } }
Squashed, thanks. Paolo
