On Thu, 16 Nov 2006 18:04:22 -0000
Avi Kivity <[EMAIL PROTECTED]> wrote:

> +static int kvm_dev_ioctl_set_msrs(struct kvm *kvm, struct kvm_msrs *msrs)
> +{
> +     struct kvm_vcpu *vcpu;
> +     struct kvm_msr_entry *entry, *entries;
> +     int rc;
> +     u32 size, num_entries, i;
> +
> +     if (msrs->vcpu < 0 || msrs->vcpu >= KVM_MAX_VCPUS)
> +             return -EINVAL;
> +
> +     num_entries = ARRAY_SIZE(msrs_to_save);
> +     if (msrs->nmsrs < num_entries) {
> +             msrs->nmsrs = num_entries; /* inform actual size */
> +             return -EINVAL;
> +     }
> +
> +     vcpu = vcpu_load(kvm, msrs->vcpu);
> +     if (!vcpu)
> +             return -ENOENT;
> +
> +     size = msrs->nmsrs * sizeof(struct kvm_msr_entry);
> +     rc = -E2BIG;
> +     if (size > 4096)
> +             goto out_vcpu;

Classic mutiplicative overflow bug.  Only msrs->nmsrs doesn't get used
again, so there is no bug here.  Yet.

> +     rc = -ENOMEM;
> +     entries = vmalloc(size);
> +     if (entries == NULL)
> +             goto out_vcpu;
> +
> +     rc = -EFAULT;
> +     if (copy_from_user(entries, msrs->entries, size))
> +             goto out_free;
> +
> +     rc = -EINVAL;
> +     for (i=0; i<num_entries; i++) {
> +             entry = &entries[i];
> +             if (set_msr(vcpu, entry->index,  entry->data))
> +                     goto out_free;
> +     }
> +
> +     rc = 0;
> +out_free:
> +     vfree(entries);
> +
> +out_vcpu:
> +     vcpu_put(vcpu);
> +
> +     return rc;
> +}

This function returns no indication of how many msrs it actually did set. 
Should it?
-
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