From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88A9119049B; Thu, 2 Jul 2026 16:40:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010409; cv=none; b=YW6QDrR4pYeGVLgc3wiTJY1aoU+X9bfjvNY6xb6/80AQAFtqbtz5cYbgwZqoWLmEeQKgOfH8EEa4DEYGdRzqUTA4dYIxijoZFZ4q8nMs0mQKlgFgxD3JB3DbHZ7KqOHdI+2QLtjJ2BdXVFGOrVkeyb0/NWI8g+AZVDgyx0MM3g4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783010409; c=relaxed/simple; bh=k6FQ4wNb7H6rjT0n7OY6luA0xVlzPNOlml/0xGg2/XQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F0y3c+Zbij0p6x4HLEd72qJFqLE/WrFfKjaaoZgku1yFL/6YDKYbZiEV+rsmu1d30tjtgve8UybeRjzMrRW4E3bXROpGh6+C/Zgxx+xrikgOppEIejHv//dUD8g7z1UDmHaz1tj0G3h3aVEnmkbYvM8+rx+usup6/1QuHH82SoA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OpEXGStB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OpEXGStB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE5E41F000E9; Thu, 2 Jul 2026 16:40:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783010408; bh=m8BCa82YwIMiQ7TKPg+Bn5y7drTCvYRV49B3/t6RkUk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OpEXGStBrMudFUT85bdIC/IpvU2v6ksN+1At/4JwEQnckulPkdCyp5GIkPIecx00B eb+TfF2LAzoGWgx1kY+1oCUzflmL7pvukAxioIT46iH3XpF1NUCQdgYlWLQnudsWMF qaSzIx3pvwamMDjul8GnP6osIkXoaKr+6y8ZcWnI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tom Lendacky , Sean Christopherson , Paolo Bonzini , Jack Wang , Sasha Levin Subject: [PATCH 6.12 097/204] KVM: SEV: Reject MMIO requests larger than 8 bytes with GHCB v2+ Date: Thu, 2 Jul 2026 18:19:14 +0200 Message-ID: <20260702155120.698485132@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155118.667618796@linuxfoundation.org> References: <20260702155118.667618796@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson commit dcf1b2d4b0564a27e4ca7c654871aab4f9620046 upstream. When using GHCB v2+, reject MMIO requests that are larger than 8 bytes. Per the GHCB spec: SW_EXITINFO2 must be less than or equal to 0x7fffffff for version 1 and less than or equal to 0x8 for all other versions. Fixes: 4af663c2f64a ("KVM: SEV: Allow per-guest configuration of GHCB protocol version") Cc: stable@vger.kernel.org Reviewed-by: Tom Lendacky Signed-off-by: Sean Christopherson Message-ID: <20260501202250.2115252-4-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Jack Wang Signed-off-by: Sasha Levin --- arch/x86/kvm/svm/sev.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 0a01971e33f0b7..497a6e70513570 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -4350,6 +4350,13 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) if (!control->exit_info_2) return 1; + if (to_kvm_sev_info(vcpu->kvm)->ghcb_version >= 2 && + control->exit_info_2 > 8) { + ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); + ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT); + return 1; + } + ret = setup_vmgexit_scratch(svm, true, control->exit_info_2); if (ret) break; @@ -4363,6 +4370,13 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) if (!control->exit_info_2) return 1; + if (to_kvm_sev_info(vcpu->kvm)->ghcb_version >= 2 && + control->exit_info_2 > 8) { + ghcb_set_sw_exit_info_1(svm->sev_es.ghcb, 2); + ghcb_set_sw_exit_info_2(svm->sev_es.ghcb, GHCB_ERR_INVALID_INPUT); + return 1; + } + ret = setup_vmgexit_scratch(svm, false, control->exit_info_2); if (ret) break; -- 2.53.0