From: Sean Christopherson <seanjc@google.com>
To: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Michael Roth <michael.roth@amd.com>
Subject: Re: [PATCH] KVM: SEV: Reject non-positive effective lengths during LAUNCH_UPDATE
Date: Mon, 8 Sep 2025 16:54:21 -0700 [thread overview]
Message-ID: <aL9srWU7gnKJzeig@google.com> (raw)
In-Reply-To: <b55f2ab4-da7c-5fed-adab-ceca54282ddb@amd.com>
On Mon, Sep 08, 2025, Tom Lendacky wrote:
> On 8/26/25 18:37, Sean Christopherson wrote:
> > diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> > index f4381878a9e5..746a57bf1f71 100644
> > --- a/arch/x86/kvm/svm/sev.c
> > +++ b/arch/x86/kvm/svm/sev.c
> > @@ -2360,6 +2360,8 @@ static int snp_launch_update(struct kvm *kvm, struct kvm_sev_cmd *argp)
> > return -EINVAL;
> >
> > npages = params.len / PAGE_SIZE;
> > + if (npages <= 0)
> > + return -EINVAL;
>
> Would it make sense to include a !params.len in the giant if check just
> above this, e.g.:
>
> if (!params.len || !PAGE_ALIGNED(params.len) || ...
>
> ?
>
> That way everything related to checking "params" remains in the one
> statement.
Oh, yeah, duh. I overlooked that the only way for npages to be '0' is if
params.len is '0', because the PAGE_ALIGNED() check will handed len == 1-4095.
Will send a v2. Thanks Tom!
prev parent reply other threads:[~2025-09-08 23:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-26 23:37 [PATCH] KVM: SEV: Reject non-positive effective lengths during LAUNCH_UPDATE Sean Christopherson
2025-09-08 21:35 ` Tom Lendacky
2025-09-08 23:54 ` Sean Christopherson [this message]
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