From nobody Fri Sep 5 20:17:17 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6641EC32792 for ; Tue, 23 Aug 2022 11:47:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358273AbiHWLrf (ORCPT ); Tue, 23 Aug 2022 07:47:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358529AbiHWLmA (ORCPT ); Tue, 23 Aug 2022 07:42:00 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E336CE32C; Tue, 23 Aug 2022 02:29:35 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C3D3BB81C8B; Tue, 23 Aug 2022 09:29:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 30D8AC433D6; Tue, 23 Aug 2022 09:29:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661246972; bh=UzHrVfXis4IWjX5ArX2hRghplCJ80F/NMD75HVyyG8w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fsOUmgTGJAkraYb2OjSNTzDiXXkZwRx1034q3MzRi6Ng8RUpL08/dFBOVFVLpgUIQ hGSfdnUrBLAIaMbraO619BQxHGjzQuR4o7eB2ZnrmjjD3LZfI8+e3j840Ym9zyyYc6 SG5jHgzC/lCvOE1DxwXsn9om6WVLgH8+BKd2BsSY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Vitaly Kuznetsov , Paolo Bonzini , Stefan Ghinea Subject: [PATCH 5.4 278/389] KVM: x86: Check lapic_in_kernel() before attempting to set a SynIC irq Date: Tue, 23 Aug 2022 10:25:56 +0200 Message-Id: <20220823080127.144141719@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080115.331990024@linuxfoundation.org> References: <20220823080115.331990024@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Vitaly Kuznetsov commit 7ec37d1cbe17d8189d9562178d8b29167fe1c31a upstream When KVM_CAP_HYPERV_SYNIC{,2} is activated, KVM already checks for irqchip_in_kernel() so normally SynIC irqs should never be set. It is, however, possible for a misbehaving VMM to write to SYNIC/STIMER MSRs causing erroneous behavior. The immediate issue being fixed is that kvm_irq_delivery_to_apic() (kvm_irq_delivery_to_apic_fast()) crashes when called with 'irq.shorthand =3D APIC_DEST_SELF' and 'src =3D=3D NULL'. Signed-off-by: Vitaly Kuznetsov Message-Id: <20220325132140.25650-2-vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Ghinea Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/hyperv.c | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -309,6 +309,9 @@ static int synic_set_irq(struct kvm_vcpu struct kvm_lapic_irq irq; int ret, vector; =20 + if (KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm)) + return -EINVAL; + if (sint >=3D ARRAY_SIZE(synic->sint)) return -EINVAL;