Re: [PATCH] KVM: arm64: Fix the upper limit of the walker range

Marc Zyngier
2025-01-14T14:55:19Z

On Tue, 14 Jan 2025 14:50:51 +0000,
Sebastian Ene <sebastianene@google.com> wrote:
>
> Prevent the walker from running into weeds when walking an
> entire address range.
>
> Signed-off-by: Sebastian Ene <sebastianene@google.com>
> ---
> arch/arm64/kvm/hyp/pgtable.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
> index 40bd55966..2ffb5571e 100644
> --- a/arch/arm64/kvm/hyp/pgtable.c
> +++ b/arch/arm64/kvm/hyp/pgtable.c
> @@ -260,7 +260,7 @@ static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_da
> {
> u32 idx;
> int ret = 0;
> - u64 limit = BIT(pgt->ia_bits);
> + u64 limit = BIT(pgt->ia_bits) - 1;
>
> if (data->addr > limit || data->end > limit)
> return -ERANGE;

Huh, nice catch. I guess this deserves a

Fixes: b1e57de62cfb4 ("KVM: arm64: Add stand-alone page-table walker infrastructure")
Cc: stable@vger.kernel.org

right?

M.

--
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