From patchwork Thu Apr 23 15:40:03 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11505923 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BB80414DD for ; Thu, 23 Apr 2020 15:40:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3AC921655 for ; Thu, 23 Apr 2020 15:40:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587656435; bh=E7hIDSjhnPmiIoxSDtBaSnp525oAZljrQLvYSUMnRqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wB3Kb6oljIFQSXMxl6bmNzlz/Ce/AXbFRcnVfA81mhP+Ehvi7I/QAOXveBTBpTKSz /qn3EyhFOFxDQT5E906fwam/WzGHO72fEG01PasdZLF3G8vHBojsZCJEsdd4IKqbDR JfZBc2WQb+R4iqSYQXAWRd+W7sa5o1kPd/qRTVPE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729310AbgDWPke (ORCPT ); Thu, 23 Apr 2020 11:40:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:51254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728865AbgDWPkd (ORCPT ); Thu, 23 Apr 2020 11:40:33 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0B34920781; Thu, 23 Apr 2020 15:40:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587656433; bh=E7hIDSjhnPmiIoxSDtBaSnp525oAZljrQLvYSUMnRqI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IOr1AEawHtAGqEWt5ye+aq959VTWkVDQD2fChx+WW/oywhsZNDQntOeSVWZB03BBq PvZHChsnt5YsaUMzh01rx5pavN5sWmnoKAcSw7vyFMkJuwwoC8ffuKl4tQZsKOHV18 sKg9+DkPSmXh7SCoGNO9rYmO/cy96K8kBbtHjxTg= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jRdxn-005oPM-Dr; Thu, 23 Apr 2020 16:40:31 +0100 From: Marc Zyngier To: Paolo Bonzini Cc: Alexandru Elisei , =?utf-8?q?Andr=C3=A9_Przywa?= =?utf-8?q?ra?= , Christoffer Dall , Julien Grall , Zenghui Yu , James Morse , Julien Thierry , Suzuki K Poulose , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: [PATCH 2/8] KVM: arm64: PSCI: Narrow input registers when using 32bit functions Date: Thu, 23 Apr 2020 16:40:03 +0100 Message-Id: <20200423154009.4113562-3-maz@kernel.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200423154009.4113562-1-maz@kernel.org> References: <20200423154009.4113562-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: pbonzini@redhat.com, alexandru.elisei@arm.com, andre.przywara@arm.com, christoffer.dall@arm.com, julien@xen.org, yuzenghui@huawei.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When a guest delibarately uses an SMC32 function number (which is allowed), we should make sure we drop the top 32bits from the input arguments, as they could legitimately be junk. Reported-by: Christoffer Dall Reviewed-by: Christoffer Dall Reviewed-by: Alexandru Elisei Signed-off-by: Marc Zyngier --- virt/kvm/arm/psci.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 14a162e295a94..3772717efe3e5 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -186,6 +186,18 @@ static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET); } +static void kvm_psci_narrow_to_32bit(struct kvm_vcpu *vcpu) +{ + int i; + + /* + * Zero the input registers' upper 32 bits. They will be fully + * zeroed on exit, so we're fine changing them in place. + */ + for (i = 1; i < 4; i++) + vcpu_set_reg(vcpu, i, lower_32_bits(vcpu_get_reg(vcpu, i))); +} + static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; @@ -210,12 +222,16 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_SUCCESS; break; case PSCI_0_2_FN_CPU_ON: + kvm_psci_narrow_to_32bit(vcpu); + fallthrough; case PSCI_0_2_FN64_CPU_ON: mutex_lock(&kvm->lock); val = kvm_psci_vcpu_on(vcpu); mutex_unlock(&kvm->lock); break; case PSCI_0_2_FN_AFFINITY_INFO: + kvm_psci_narrow_to_32bit(vcpu); + fallthrough; case PSCI_0_2_FN64_AFFINITY_INFO: val = kvm_psci_vcpu_affinity_info(vcpu); break;