From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
Mikhail Lobanov <m.lobanov@rosa.ru>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Maxim Levitsky <mlevitsk@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
lvc-project@linuxtesting.org, stable@vger.kernel.org
Subject: Re: [PATCH v3] KVM: SVM: forcibly leave SMM mode on vCPU reset
Date: Fri, 25 Apr 2025 15:08:58 -0700 [thread overview]
Message-ID: <174559665447.890486.10602051835802598167.b4-ty@google.com> (raw)
In-Reply-To: <20250414171207.155121-1-m.lobanov@rosa.ru>
On Mon, 14 Apr 2025 20:12:06 +0300, Mikhail Lobanov wrote:
> Previously, commit ed129ec9057f ("KVM: x86: forcibly leave nested mode
> on vCPU reset") addressed an issue where a triple fault occurring in
> nested mode could lead to use-after-free scenarios. However, the commit
> did not handle the analogous situation for System Management Mode (SMM).
>
> This omission results in triggering a WARN when a vCPU reset occurs
> while still in SMM mode, due to the check in kvm_vcpu_reset(). This
> situation was reprodused using Syzkaller by:
> 1) Creating a KVM VM and vCPU
> 2) Sending a KVM_SMI ioctl to explicitly enter SMM
> 3) Executing invalid instructions causing consecutive exceptions and
> eventually a triple fault
>
> [...]
Applied to kvm-x86 fixes. I massaged the shortlog+changelog, as firing INIT
isn't architectural behavior, it's simply the least awful option, and more
importantly, it's KVM's existing behavior.
Thanks!
[1/1] KVM: SVM: forcibly leave SMM mode on vCPU reset
commit: a2620f8932fa9fdabc3d78ed6efb004ca409019f
--
https://github.com/kvm-x86/linux/tree/next
prev parent reply other threads:[~2025-04-25 22:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-14 17:12 Mikhail Lobanov
2025-04-25 22:08 ` Sean Christopherson [this message]
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