From patchwork Wed Apr 1 16:58:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11469345 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 F09A017EF for ; Wed, 1 Apr 2020 16:58:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC5582078C for ; Wed, 1 Apr 2020 16:58:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585760312; bh=FuGfYh1+EXJyAtf5C2GDqinq2NnOg9RLDsgqd9Et3Fc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=M0SPLSPrvKUvhgm05j4Vw9IMCsdAJgrhzKlw47r7P+vnpUc63guvDpaaD51mQXF9C XW5t3kWRzPA0+8NyPPCwK5V0vee5RlmnoOUh7YKIW9QEiye00AnAH2XDL1zEcmW59y GKUE9xQNfpv6uzhaKnxtSefghWXOqRn5NsJThg5g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733112AbgDAQ6c (ORCPT ); Wed, 1 Apr 2020 12:58:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:57620 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732747AbgDAQ6b (ORCPT ); Wed, 1 Apr 2020 12:58:31 -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 27DFE20714; Wed, 1 Apr 2020 16:58:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585760311; bh=FuGfYh1+EXJyAtf5C2GDqinq2NnOg9RLDsgqd9Et3Fc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=i28ZEb0cbGWPWRXxU2+ocBpFuSiIGV3bRbJUY/uTnhC2OaYZvpgPpBAAmKBvgHsg8 IhxMs03xJXiVPZ4SVzWURn8PR6Mttt+C1AXPzpBP5JWJDt3dc6REQuFkWCOQNs1/yz T159f8D3kIbJ+77A/BnSFuoATrUrPIq7qb2SIxKs= 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 1jJghB-00Haev-Bt; Wed, 01 Apr 2020 17:58:29 +0100 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Christoffer Dall , James Morse , Julien Thierry , Suzuki K Poulose , Christoffer Dall Subject: [PATCH 1/2] KVM: arm64: PSCI: Narrow input registers when using 32bit functions Date: Wed, 1 Apr 2020 17:58:15 +0100 Message-Id: <20200401165816.530281-2-maz@kernel.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200401165816.530281-1-maz@kernel.org> References: <20200401165816.530281-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Christoffer.Dall@arm.com, james.morse@arm.com, julien.thierry.kdev@gmail.com, suzuki.poulose@arm.com, christoffer.dall@arm.com 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 SSMC32 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 Signed-off-by: Marc Zyngier Reviewed-by: Christoffer Dall Reviewed-by: Alexandru Elisei --- 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 17e2bdd4b76f..69ff4a51ceb5 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -187,6 +187,18 @@ 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, (u32)vcpu_get_reg(vcpu, i)); +} + static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; @@ -211,12 +223,16 @@ 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;