Re: [PATCH v3 3/4] KVM: PPC: Book3S HV: XICS: Avoid NULL ptr deref in kvmppc_xive_cleanup_vcpu()

[IBM]

Gautam Menghani <gautam@xxxxxxxxxxxxx> writes:

> In kvmppc_xive_connect_vcpu() if there is a failure before
> xc->vp_ipi_data is setup, it can result in a NULL pointer dereference in
> kvmppc_xive_cleanup_vcpu() when accessing the MMIO page in
> xive_vm_esb_load(). Fix this by adding a check before masking
> the VP IPI before accessing the MMIO pages.
>
> Fixes: 5af50993850a ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
> Cc: stable@xxxxxxxxxxxxxxx # 4.12+
> Signed-off-by: Gautam Menghani <gautam@xxxxxxxxxxxxx>
> ---
> v3:
> 1. Add some more info to the patch description.
>
> v2:
> 1. New patch - Introduced to fix the scenario where NULL ptr deref is
> possible. (Sashiko)
>

Make sense. However, the order of patch-2 and patch-3 should be
reversed. Otherwise LGTM.

Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>