On 07/05/13 13:55, Andre Przywara wrote:
> Some ARM KVM VCPU ioctls require the vCPU to be properly initialized
> with the KVM_ARM_VCPU_INIT ioctl before being used with further
> requests. KVM_RUN checks whether this initialization has been
> done, but other ioctls do not.
> Namely KVM_GET_REG_LIST will dereference an array with index -1
> without initialization and thus leads to a kernel oops.
> Fix this by adding checks before executing the ioctl handlers.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx>
> ---
> arch/arm/kvm/arm.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index c1fe498..0c571ff 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -893,6 +893,11 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> case KVM_SET_ONE_REG:
> case KVM_GET_ONE_REG: {
> struct kvm_one_reg reg;
> +
> + /* Make sure they initialize the vcpu with KVM_ARM_VCPU_INIT */
> + if (unlikely(vcpu->arch.target < 0))
> + return -ENOEXEC;
> +
> if (copy_from_user(®, argp, sizeof(reg)))
> return -EFAULT;
> if (ioctl == KVM_SET_ONE_REG)
> @@ -905,6 +910,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
> struct kvm_reg_list reg_list;
> unsigned n;
>
> + /* Make sure they initialize the vcpu with KVM_ARM_VCPU_INIT */
> + if (unlikely(vcpu->arch.target < 0))
> + return -ENOEXEC;
> +
> if (copy_from_user(®_list, user_list, sizeof(reg_list)))
> return -EFAULT;
> n = reg_list.n;
>
So we also have the same snippet in kvm_arch_vcpu_ioctl_run().
Can you create a static function (kvm_vcpu_initialized?) containing that
code and make all three sites use it?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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