From: Sean Christopherson <seanjc@google.com>
To: Amirmohammad Eftekhar <amirmohammad.eftekhar@cispa.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] KVM: VMX: Add array_index_nospec() to evmcs_field_offset()
Date: Fri, 23 Oct 2026 18:17:18 -0700 [thread overview]
Message-ID: <atwHHh1z3zVzLV4P@google.com> (raw)
In-Reply-To: <20261023171307.636760-1-amirmohammad.eftekhar@cispa.de>
On Fri, Oct 23, 2026, Amirmohammad Eftekhar wrote:
> From: Amirmohammad Eftekhar <amirmohammad.eftekhar@cispa.de>
>
> evmcs_field_offset() bounds-checks the guest-supplied field index against
> nr_evmcs_1_fields and then indexes vmcs_field_to_evmcs_1[] with it, but,
> unlike its vmcs12 counterpart get_vmcs12_field_offset(), it does not clamp
> the index with array_index_nospec() after the check. The field index is
> derived from a guest-supplied VMCS field encoding on the enlightened
> VMREAD/VMWRITE path, so the array access can be performed speculatively
> past the bounds check (Spectre v1), disclosing memory adjacent to
> vmcs_field_to_evmcs_1[].
>
> Clamp the index with array_index_nospec() immediately after the bounds
> check, mirroring get_vmcs12_field_offset().
>
> Signed-off-by: Amirmohammad Eftekhar <amirmohammad.eftekhar@cispa.de>
> ---
You already posted this exact patch[*], and at a glance several of the bug reports
appear to be duplicates as well. Please stop spamming duplicates. If you have
questions about the flow and/or timing of patches, e.g. since we're in a merge
window, then Documentation/process/maintainer-kvm-x86.rst is your friend.
[*] https://lore.kernel.org/all/20261017093016.32348-3-amirmohammad.eftekhar@cispa.de
next prev parent reply other threads:[~2026-10-24 1:17 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-23 17:13 [PATCH] KVM: VMX: Add array_index_nospec() to evmcs_field_offset() Amirmohammad Eftekhar
2026-10-24 1:17 ` Sean Christopherson [this message]
-- strict thread matches above, loose matches on Subject: below --
2026-10-17 9:30 Amirmohammad Eftekhar
2026-10-26 9:00 ` Vitaly Kuznetsov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=atwHHh1z3zVzLV4P@google.com \
--to=seanjc@google.com \
--cc=amirmohammad.eftekhar@cispa.de \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=vkuznets@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.