Re: [PATCH v3] KVM: PPC: Fix callback check in kvmppc_gsm_refresh_info

From: Gautam Menghani

Date: Mon Sep 21 2026 - 07:28:29 EST


On Fri, Sep 18, 2026 at 09:31:24PM +0700, Bui Nguyen Nhu Quynh wrote:
> The kvmppc_gsm_refresh_info() function incorrectly checks for the
> presence of the fill_info callback instead of refresh_info.
>
> This can lead to:
> - NULL pointer dereference if refresh_info is NULL but fill_info is present
> - EINVAL return if refresh_info is present but fill_info is NULL
>
> Fix this by checking the correct callback.
>
> Fixes: 6ccbbc33f06ad ("KVM: PPC: Add helper library for Guest State Buffers")
> Signed-off-by: Bui Nguyen Nhu Quynh <kaylovefoss@xxxxxxxxx>
> ---
> v3:
> - Resend to fix whitespace handling issue on v2. No code changes.
>

You missed the v2 changelog here. You should mention all changes
introduced in every version.

> arch/powerpc/kvm/guest-state-buffer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kvm/guest-state-buffer.c b/arch/powerpc/kvm/guest-state-buffer.c
> index 42843eca6727..aeb586ba4523 100644
> --- a/arch/powerpc/kvm/guest-state-buffer.c
> +++ b/arch/powerpc/kvm/guest-state-buffer.c
> @@ -598,7 +598,7 @@ EXPORT_SYMBOL_GPL(kvmppc_gsm_fill_info);
> int kvmppc_gsm_refresh_info(struct kvmppc_gs_msg *gsm,
> struct kvmppc_gs_buff *gsb)
> {
> - if (!gsm->ops->fill_info)
> + if (!gsm->ops->refresh_info)
> return -EINVAL;
>
> return gsm->ops->refresh_info(gsm, gsb);
> --
> 2.54.0
>
>

LGTM, this is a copy paste mistake. I did some quick sanity test with
this patch applied.

Tested-by: Gautam Menghani <gautam@xxxxxxxxxxxxx>