linux-kernel - Re: [PATCH v4 10/12] KVM: x86: never write to memory from kvm_vcpu_check

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALMp9eTT97oDmQT7pxeOMLQbt-371aMtC2Kev+-kWXVRDVrjeg@mail.gmail.com>
Date:   Sun, 10 Dec 2023 14:52:59 -0800
From:   Jim Mattson <jmattson@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>
Cc:     alexandru.elisei@....com, anup@...infault.org,
        aou@...s.berkeley.edu, atishp@...shpatra.org,
        borntraeger@...ux.ibm.com, chenhuacai@...nel.org, david@...hat.com,
        frankja@...ux.ibm.com, imbrenda@...ux.ibm.com, james.morse@....com,
        kvm-riscv@...ts.infradead.org, kvm@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        linux-mips@...r.kernel.org, linux-riscv@...ts.infradead.org,
        linuxppc-dev@...ts.ozlabs.org, maz@...nel.org, mlevitsk@...hat.com,
        oliver.upton@...ux.dev, palmer@...belt.com,
        paul.walmsley@...ive.com, pbonzini@...hat.com,
        suzuki.poulose@....com
Subject: Re: [PATCH v4 10/12] KVM: x86: never write to memory from kvm_vcpu_check_block()

On Thu, Dec 7, 2023 at 8:21 AM Sean Christopherson <seanjc@...gle.com> wrote:
> Doh.  We got the less obvious cases and missed the obvious one.
>
> Ugh, and we also missed a related mess in kvm_guest_apic_has_interrupt().  That
> thing should really be folded into vmx_has_nested_events().
>
> Good gravy.  And vmx_interrupt_blocked() does the wrong thing because that
> specifically checks if L1 interrupts are blocked.
>
> Compile tested only, and definitely needs to be chunked into multiple patches,
> but I think something like this mess?

The proposed patch does not fix the problem. In fact, it messes things
up so much that I don't get any test results back.

Google has an internal K-U-T test that demonstrates the problem. I
will post it soon.