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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 F24B0C35657 for ; Fri, 21 Feb 2020 16:05:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3E2D2067D for ; Fri, 21 Feb 2020 16:05:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WjzTvRtK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728985AbgBUQFD (ORCPT ); Fri, 21 Feb 2020 11:05:03 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:23993 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728130AbgBUQFD (ORCPT ); Fri, 21 Feb 2020 11:05:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582301102; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=b/XFBGDvO3UXFNECW6P4x7ADbFivKxUA9DrB33OKpco=; b=WjzTvRtKzRTq5zsdb4tDRrs26r0IxpM+lx6E1er697xfHJ+XO8V2YQ4BMLJ/w56Sw0BIot it09RaVOZd00/Sr4YmYIdwp3DXSiy8PsG1haPUQznYbPcByQalDxFIwCBZlJQf2t5h123A STYZv5aX80tAd2OiBq65wAV3sXcWohM= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-472-GZPzp5fqM1OzzsI9NDh1EQ-1; Fri, 21 Feb 2020 11:05:00 -0500 X-MC-Unique: GZPzp5fqM1OzzsI9NDh1EQ-1 Received: by mail-wr1-f71.google.com with SMTP id p8so1221090wrw.5 for ; Fri, 21 Feb 2020 08:05:00 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=b/XFBGDvO3UXFNECW6P4x7ADbFivKxUA9DrB33OKpco=; b=B6HoheHgY/hcqFNLatwRzUXYx3xdV5N45ixMxvHtlrkRwZsk72uXKw5ZKgeKERrCRp xEldtnzdNADn3ZAzsKCiOqPLDH9WurjHjI/3w5W5tRULDexQXuQtmYkcQ0zcJehXn2cp LCUXxrI1yg9XfpyBL1VBWI0fxihtxCCuUgwr3k9TcnSF6uC21Z4Hfqqb2BwcMgYCjdNe HZXpYXZMNmU9qbaFQwQg4FHemtyGPkc6UQyvyeEY9XmI0QDpW2GxSyHn1jpe+dtf1vN1 6mDxejd14wpa0ZTVM0vDBtVolULOwAOPH8nFkB29br90uF04OUgiYuTS5K52/Avqwzih m5ow== X-Gm-Message-State: APjAAAXfVgfqRt1dSVJGEXYcMfxhDPHV7I7JKD1uQNyiCh9Ya+VGCDyp AScyH2A8WHy1hQAkXHymE8v3qC/JswJtUdk4ymitSvvX1GXi//dP4zjwHN8fhpXgNpO4yroprvl TacrMjkbsaE7iUlBRQzzQHdab X-Received: by 2002:adf:c453:: with SMTP id a19mr49870841wrg.341.1582301097009; Fri, 21 Feb 2020 08:04:57 -0800 (PST) X-Google-Smtp-Source: APXvYqxcNZy47AONFyMZVt1Po1fABbweri3/gLj6WIymqQWTWEqb3bitDkuCMdiuyDTbVITIsZ7gWA== X-Received: by 2002:adf:c453:: with SMTP id a19mr49870335wrg.341.1582301089399; Fri, 21 Feb 2020 08:04:49 -0800 (PST) Received: from [192.168.178.40] ([151.20.135.128]) by smtp.gmail.com with ESMTPSA id 25sm4424881wmi.32.2020.02.21.08.04.48 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Feb 2020 08:04:48 -0800 (PST) Subject: Re: [PATCH] kvm: x86: svm: Fix NULL pointer dereference when AVIC not enabled To: Alex Williamson , Suravee Suthikulpanit Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, joro@8bytes.org, jon.grimm@amd.com References: <1582296737-13086-1-git-send-email-suravee.suthikulpanit@amd.com> <20200221083934.3ed38014@x1.home> From: Paolo Bonzini Message-ID: Date: Fri, 21 Feb 2020 17:04:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20200221083934.3ed38014@x1.home> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21/02/20 16:39, Alex Williamson wrote: > On Fri, 21 Feb 2020 08:52:17 -0600 > Suravee Suthikulpanit wrote: > >> Launching VM w/ AVIC disabled together with pass-through device >> results in NULL pointer dereference bug with the following call trace. >> >> RIP: 0010:svm_refresh_apicv_exec_ctrl+0x17e/0x1a0 [kvm_amd] >> >> Call Trace: >> kvm_vcpu_update_apicv+0x44/0x60 [kvm] >> kvm_arch_vcpu_ioctl_run+0x3f4/0x1c80 [kvm] >> kvm_vcpu_ioctl+0x3d8/0x650 [kvm] >> do_vfs_ioctl+0xaa/0x660 >> ? tomoyo_file_ioctl+0x19/0x20 >> ksys_ioctl+0x67/0x90 >> __x64_sys_ioctl+0x1a/0x20 >> do_syscall_64+0x57/0x190 >> entry_SYSCALL_64_after_hwframe+0x44/0xa9 >> >> Investigation shows that this is due to the uninitialized usage of >> struct vapu_svm.ir_list in the svm_set_pi_irte_mode(), which is >> called from svm_refresh_apicv_exec_ctrl(). >> >> The ir_list is initialized only if AVIC is enabled. So, fixes by >> adding a check if AVIC is enabled in the svm_refresh_apicv_exec_ctrl(). >> >> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206579 >> Fixes: 8937d762396d ("kvm: x86: svm: Add support to (de)activate posted interrupts.") >> Signed-off-by: Suravee Suthikulpanit >> Cc: Alex Williamson >> --- >> arch/x86/kvm/svm.c | 3 +++ >> 1 file changed, 3 insertions(+) > > Works for me, thanks Suravee! > > Tested-by: Alex Williamson > >> >> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c >> index 19035fb..1858455 100644 >> --- a/arch/x86/kvm/svm.c >> +++ b/arch/x86/kvm/svm.c >> @@ -5222,6 +5222,9 @@ static void svm_refresh_apicv_exec_ctrl(struct kvm_vcpu *vcpu) >> struct vmcb *vmcb = svm->vmcb; >> bool activated = kvm_vcpu_apicv_active(vcpu); >> >> + if (!avic) >> + return; >> + >> if (activated) { >> /** >> * During AVIC temporary deactivation, guest could update > Thanks to both of you. I'll get it to Linus next Monday. Paolo