From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:54968 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934933AbeFRITy (ORCPT ); Mon, 18 Jun 2018 04:19:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mark Rutland , Christoffer Dall , Marc Zyngier , kvmarm@lists.cs.columbia.edu, Will Deacon , Sasha Levin Subject: [PATCH 4.16 107/279] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr() Date: Mon, 18 Jun 2018 10:11:32 +0200 Message-Id: <20180618080613.251884990@linuxfoundation.org> In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland [ Upstream commit 5e1ca5e23b167987d5b6d8b08f2d5b7dd2d13f49 ] It's possible for userspace to control n. Sanitize n when using it as an array index. Note that while it appears that n must be bound to the interval [0,3] due to the way it is extracted from addr, we cannot guarantee that compiler transformations (and/or future refactoring) will ensure this is the case, and given this is a slow path it's better to always perform the masking. Found by smatch. Signed-off-by: Mark Rutland Acked-by: Christoffer Dall Acked-by: Marc Zyngier Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Will Deacon Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- virt/kvm/arm/vgic/vgic-mmio-v2.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c @@ -14,6 +14,8 @@ #include #include #include +#include + #include #include @@ -324,6 +326,9 @@ static unsigned long vgic_mmio_read_apr( if (n > vgic_v3_max_apr_idx(vcpu)) return 0; + + n = array_index_nospec(n, 4); + /* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */ return vgicv3->vgic_ap1r[n]; }