From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FA34C04A6B for ; Mon, 6 May 2019 15:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 42DCF2054F for ; Mon, 6 May 2019 15:05:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557155105; bh=BKhbmqv6L6lntJ0v+ab+H4zgl/rxM7OzeccCAY5BKTA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=d7pWq7RbS1fEe3Kdf2MP/wu8zyih9il6Rbts8CuaH7n4XlsAzQLLzfskPpGkN2Fbb bzA5FyY6puFQFDZOvbQb8qxthCHCE4UWSAl62vbUQrluaDLrpx9fMHshV8FSypBQeC RtGKtSCmBPkKQDNizx5YhXd/ZuJG3vjUz9J6/6ZY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727199AbfEFOi7 (ORCPT ); Mon, 6 May 2019 10:38:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:60192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726439AbfEFOix (ORCPT ); Mon, 6 May 2019 10:38:53 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 E8CDE214AF; Mon, 6 May 2019 14:38:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1557153532; bh=BKhbmqv6L6lntJ0v+ab+H4zgl/rxM7OzeccCAY5BKTA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eEex5zyep3Il6EmGrJerD3x3YUsVqB/uxJDGZUwpf7ZNqrWaB95d6XCU5tfbBbC9/ uSdE2zkMpa0NYYh8vD1MtVM2PvdHZagMxn5Phty9bvDWmV7lJXRSvAwxOp9un2VLyl zFhVqysVoluJUZIBB5PS5ecUW56Egc0sQqwFLO7E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+f7e65445a40d3e0e4ebf@syzkaller.appspotmail.com, Sean Christopherson , Konrad Rzeszutek Wilk , Paolo Bonzini Subject: [PATCH 5.0 103/122] KVM: lapic: Check for in-kernel LAPIC before deferencing apic pointer Date: Mon, 6 May 2019 16:32:41 +0200 Message-Id: <20190506143103.965452572@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190506143054.670334917@linuxfoundation.org> References: <20190506143054.670334917@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sean Christopherson commit b904cb8dff824b79233e82c078837627ebd52717 upstream. ...to avoid dereferencing a null pointer when querying the per-vCPU timer advance. Fixes: 39497d7660d98 ("KVM: lapic: Track lapic timer advance per vCPU") Reported-by: syzbot+f7e65445a40d3e0e4ebf@syzkaller.appspotmail.com Signed-off-by: Sean Christopherson Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/lapic.c | 3 --- arch/x86/kvm/x86.c | 3 ++- 2 files changed, 2 insertions(+), 4 deletions(-) --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1504,9 +1504,6 @@ void wait_lapic_expire(struct kvm_vcpu * u32 timer_advance_ns = apic->lapic_timer.timer_advance_ns; u64 guest_tsc, tsc_deadline, ns; - if (!lapic_in_kernel(vcpu)) - return; - if (apic->lapic_timer.expired_tscdeadline == 0) return; --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7886,7 +7886,8 @@ static int vcpu_enter_guest(struct kvm_v } trace_kvm_entry(vcpu->vcpu_id); - if (vcpu->arch.apic->lapic_timer.timer_advance_ns) + if (lapic_in_kernel(vcpu) && + vcpu->arch.apic->lapic_timer.timer_advance_ns) wait_lapic_expire(vcpu); guest_enter_irqoff();