From patchwork Wed Dec 12 20:11:23 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 10727077 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BBE8113AF for ; Wed, 12 Dec 2018 20:12:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AAC2F2BA2A for ; Wed, 12 Dec 2018 20:12:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9E4B92BA2D; Wed, 12 Dec 2018 20:12:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4152B2BA2A for ; Wed, 12 Dec 2018 20:12:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Subject:To:From :Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=8OedJxX/gLCyKc4VSoKaF+qtMIsmdXP2tXgKd3Qkn6k=; b=XGgV6HN4eZbr9q zand2GPBtSO80G6nVVZHC09uQFHHw+Du67fK0AN3KFHuv5vQgo/RxULzQ2p2ihLUiG2xTruW7+AbB TKq9xAcyGMxw8LAho1n/100Ws5KbBhpfokzsIF3c1+zFWYeRGDxWJI/eLB495PvKYQgfgqonLhVYz sT2RQdByPwA0dalZxRiv5+Fuf/mEPeZyHk1bmZiXcdIrRZgwgHXb/laNi6nUnoEF9KNzDJfVLluD8 xYYpL4kZgyj1+NskwjHbe2a79VAuiIhkwdrJ6Ayy3TUCmzn7yz0Q6g7fQ8+t6Y1J9O9D+UYytgOw/ g/nQ6vYIn8064/oMgaPg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gXArZ-0001yU-8x; Wed, 12 Dec 2018 20:12:09 +0000 Received: from gateway21.websitewelcome.com ([192.185.45.38]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gXArW-0001xM-AQ for linux-arm-kernel@lists.infradead.org; Wed, 12 Dec 2018 20:12:07 +0000 Received: from cm10.websitewelcome.com (cm10.websitewelcome.com [100.42.49.4]) by gateway21.websitewelcome.com (Postfix) with ESMTP id CF29D400DC962 for ; Wed, 12 Dec 2018 14:11:42 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id XAr8g3v6EaEIgXAr8grF5d; Wed, 12 Dec 2018 14:11:42 -0600 X-Authority-Reason: nr=8 Received: from [189.250.70.203] (port=45282 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gXAqp-003BG9-PE; Wed, 12 Dec 2018 14:11:42 -0600 Date: Wed, 12 Dec 2018 14:11:23 -0600 From: "Gustavo A. R. Silva" To: Mark Rutland , Christoffer Dall , Marc Zyngier , Will Deacon Subject: [PATCH] KVM: arm/arm64: vgic: fix off-by-one bug in vgic_get_irq() Message-ID: <20181212201123.GA26674@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - lists.infradead.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.70.203 X-Source-L: No X-Exim-ID: 1gXAqp-003BG9-PE X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.70.203]:45282 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181212_121206_411182_6B04E01F X-CRM114-Status: GOOD ( 10.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Gustavo A. R. Silva" , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When using the nospec API, it should be taken into account that: "...if the CPU speculates past the bounds check then * array_index_nospec() will clamp the index within the range of [0, * size)." The above is part of the header for macro array_index_nospec() in linux/nospec.h Now, in this particular case, if intid evaluates to exactly VGIC_MAX_SPI or to exaclty VGIC_MAX_PRIVATE, the array_index_nospec() macro ends up returning VGIC_MAX_SPI - 1 or VGIC_MAX_PRIVATE - 1 respectively, instead of VGIC_MAX_SPI or VGIC_MAX_PRIVATE, which, based on the original logic: /* SGIs and PPIs */ if (intid <= VGIC_MAX_PRIVATE) return &vcpu->arch.vgic_cpu.private_irqs[intid]; /* SPIs */ if (intid <= VGIC_MAX_SPI) return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS]; are valid values for intid. Fix this by calling array_index_nospec() macro with VGIC_MAX_PRIVATE + 1 and VGIC_MAX_SPI + 1 as arguments for its parameter size. Fixes: 41b87599c743 ("KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- virt/kvm/arm/vgic/vgic.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index 50e25438fb3c..5db40696055a 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -103,13 +103,13 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu, { /* SGIs and PPIs */ if (intid <= VGIC_MAX_PRIVATE) { - intid = array_index_nospec(intid, VGIC_MAX_PRIVATE); + intid = array_index_nospec(intid, VGIC_MAX_PRIVATE + 1); return &vcpu->arch.vgic_cpu.private_irqs[intid]; } /* SPIs */ if (intid <= VGIC_MAX_SPI) { - intid = array_index_nospec(intid, VGIC_MAX_SPI); + intid = array_index_nospec(intid, VGIC_MAX_SPI + 1); return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS]; }