On Wed, 06 Jul 2022 20:29:57 +0530 Jue Wang <juew@xxxxxxxxxx> wrote > Fix an access to vcpu->arch.apic when KVM_X86_SETUP_MCE is called > without KVM_CREATE_IRQCHIP called or KVM_CAP_SPLIT_IRQCHIP is > enabled. > > Reported-by: https://syzkaller.appspot.com/bug?id=10b9b238e087a6c9bef2cc48bee2375f58fabbfc > > Fixes: 4b903561ec49 ("KVM: x86: Add Corrected Machine Check Interrupt (CMCI) emulation to lapic.") > Signed-off-by: Jue Wang <juew@xxxxxxxxxx> > --- > arch/x86/kvm/x86.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > The syzkaller dashboard says to use the following line: Reported-by: syzbot+8cdad6430c24f396f158@xxxxxxxxxxxxxxxxxxxxxxxxx Tested-by: Siddh Raman Pant <code@xxxxxxxx> Thanks, Siddh > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 4322a1365f74..5913f90ec3f2 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -4820,8 +4820,9 @@ static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu, > if (mcg_cap & MCG_CMCI_P) > vcpu->arch.mci_ctl2_banks[bank] = 0; > } > - vcpu->arch.apic->nr_lvt_entries = > - KVM_APIC_MAX_NR_LVT_ENTRIES - !(mcg_cap & MCG_CMCI_P); > + if (lapic_in_kernel(vcpu)) > + vcpu->arch.apic->nr_lvt_entries = > + KVM_APIC_MAX_NR_LVT_ENTRIES - !(mcg_cap & MCG_CMCI_P); > > static_call(kvm_x86_setup_mce)(vcpu); > out: > -- > 2.37.0.rc0.161.g10f37bed90-goog > >
