| Message ID | 1455285615-6631-1-git-send-email-rkrcmar@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> -----Original Message----- > From: Radim Kr?má? [mailto:rkrcmar@redhat.com] > Sent: Friday, February 12, 2016 10:00 PM > To: linux@vger.kernel.org > Cc: kvm@vger.kernel.org; Dan Carpenter <dan.carpenter@oracle.com>; Wu, > Feng <feng.wu@intel.com>; Paolo Bonzini <pbonzini@redhat.com> > Subject: [PATCH] KVM: x86: fix *NULL on invalid low-prio irq > > Smatch noticed a NULL dereference in kvm_intr_is_single_vcpu_fast that > happens if VM already warned about invalid lowest-priority interrupt. > > Create a function for common code while fixing it. Thanks for the fix, Radim! I just saw the report by Dan and cooked a patch for it. Your patch looks good :) Thanks, Feng
2016-02-12 14:10+0000, Wu, Feng: >> From: Radim Kr?má? [mailto:rkrcmar@redhat.com] >> Smatch noticed a NULL dereference in kvm_intr_is_single_vcpu_fast that >> happens if VM already warned about invalid lowest-priority interrupt. >> >> Create a function for common code while fixing it. > > Thanks for the fix, Radim! I just saw the report by Dan and cooked a patch > for it. (Sorry for the duplication of effort, I will wait longer next time.) > Your patch looks good :) Thanks. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> -----Original Message----- > From: Radim Krcmár [mailto:rkrcmar@redhat.com] > Sent: Friday, February 12, 2016 10:28 PM > To: Wu, Feng <feng.wu@intel.com> > Cc: linux@vger.kernel.org; kvm@vger.kernel.org; Dan Carpenter > <dan.carpenter@oracle.com>; Paolo Bonzini <pbonzini@redhat.com> > Subject: Re: [PATCH] KVM: x86: fix *NULL on invalid low-prio irq > > 2016-02-12 14:10+0000, Wu, Feng: > >> From: Radim Kr?má? [mailto:rkrcmar@redhat.com] > >> Smatch noticed a NULL dereference in kvm_intr_is_single_vcpu_fast that > >> happens if VM already warned about invalid lowest-priority interrupt. > >> > >> Create a function for common code while fixing it. > > > > Thanks for the fix, Radim! I just saw the report by Dan and cooked a patch > > for it. > > (Sorry for the duplication of effort, I will wait longer next time.) No problem, that's fine. I didn't notice the report in time due to holiday. But it is good to having you help to fix it! :) Thanks, Feng > > > Your patch looks good :) > > Thanks.
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 1482a581a83c..cf74404230ca 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -685,6 +685,15 @@ int kvm_vector_to_index(u32 vector, u32 dest_vcpus, return idx; } +static void kvm_apic_disabled_lapic_found(struct kvm *kvm) +{ + if (!kvm->arch.disabled_lapic_found) { + kvm->arch.disabled_lapic_found = true; + printk(KERN_INFO + "Disabled LAPIC found during irq injection\n"); + } +} + bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, struct kvm_lapic_irq *irq, int *r, unsigned long *dest_map) { @@ -763,15 +772,8 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, idx = kvm_vector_to_index(irq->vector, dest_vcpus, &bitmap, 16); - /* - * We may find a hardware disabled LAPIC here, if that - * is the case, print out a error message once for each - * guest and return. - */ - if (!dst[idx] && !kvm->arch.disabled_lapic_found) { - kvm->arch.disabled_lapic_found = true; - printk(KERN_INFO - "Disabled LAPIC found during irq injection\n"); + if (!dst[idx]) { + kvm_apic_disabled_lapic_found(kvm); goto out; } @@ -859,16 +861,9 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq, idx = kvm_vector_to_index(irq->vector, dest_vcpus, &bitmap, 16); - /* - * We may find a hardware disabled LAPIC here, if that - * is the case, print out a error message once for each - * guest and return - */ dst = map->logical_map[cid][idx]; - if (!dst && !kvm->arch.disabled_lapic_found) { - kvm->arch.disabled_lapic_found = true; - printk(KERN_INFO - "Disabled LAPIC found during irq injection\n"); + if (!dst) { + kvm_apic_disabled_lapic_found(kvm); goto out; }
Smatch noticed a NULL dereference in kvm_intr_is_single_vcpu_fast that happens if VM already warned about invalid lowest-priority interrupt. Create a function for common code while fixing it. Fixes: 6228a0da8057 ("KVM: x86: Add lowest-priority support for vt-d posted-interrupts") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Radim Kr?má? <rkrcmar@redhat.com> --- arch/x86/kvm/lapic.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-)