From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: [PATCH 4.14 071/189] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr() Date: Mon, 18 Jun 2018 10:12:47 +0200 Message-ID: <20180618081212.145698964@linuxfoundation.org> References: <20180618081209.254234434@linuxfoundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 9D58349FA8 for ; Mon, 18 Jun 2018 04:20:54 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1TqFtie5wjRU for ; Mon, 18 Jun 2018 04:20:32 -0400 (EDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 9333440192 for ; Mon, 18 Jun 2018 04:20:32 -0400 (EDT) In-Reply-To: <20180618081209.254234434@linuxfoundation.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: linux-kernel@vger.kernel.org Cc: Marc Zyngier , Greg Kroah-Hartman , Will Deacon , stable@vger.kernel.org, Sasha Levin , kvmarm@lists.cs.columbia.edu List-Id: kvmarm@lists.cs.columbia.edu 4.14-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 @@ -320,6 +322,9 @@ 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]; }