Re: [PATCH] SVM: nSVM: fix resource leak on error path

[Maxim Levitsky <mlevitsk@redhat.com>]

On Mon, 2020-09-14 at 20:45 +0100, Alex Dewar wrote:
> In svm_set_nested_state(), if nested_svm_vmrun_msrpm() returns false,
> then variables save and ctl will leak. Fix this.
> 
> Fixes: 772b81bb2f9b ("SVM: nSVM: setup nested msr permission bitmap on nested state load")
> Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
> ---
>  arch/x86/kvm/svm/nested.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
> index 598a769f1961..85f572cbabe4 100644
> --- a/arch/x86/kvm/svm/nested.c
> +++ b/arch/x86/kvm/svm/nested.c
> @@ -1148,7 +1148,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
>  	nested_prepare_vmcb_control(svm);
>  
>  	if (!nested_svm_vmrun_msrpm(svm))
> -		return -EINVAL;
> +		goto out_free;	/* ret == -EINVAL */
>  
>  out_set_gif:
>  	svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));

I think that this patch is based on unmerged patch, since I don't see
any memory allocation in nested_svm_vmrun_msrpm, nor out_free label.
in nether kvm/master, kvm/queue nor in upstream/master

If I recall correctly that would be something about allocating ctrl/save
dynamically rather than on stack.

Best regards,
	Maxim Levitsky