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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 6AA60C4338F for ; Thu, 29 Jul 2021 12:49:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 00C666018A for ; Thu, 29 Jul 2021 12:49:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 00C666018A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:60764 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m95T9-00062D-Tp for qemu-devel@archiver.kernel.org; Thu, 29 Jul 2021 08:48:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39366) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m95RX-0003S8-56 for qemu-devel@nongnu.org; Thu, 29 Jul 2021 08:47:19 -0400 Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]:37758) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m95RV-0007VL-JA for qemu-devel@nongnu.org; Thu, 29 Jul 2021 08:47:18 -0400 Received: by mail-ed1-x535.google.com with SMTP id h8so8053642ede.4 for ; Thu, 29 Jul 2021 05:47:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=bVkJDxISQsJiDctueFKDZan7YC/pcML2RCP1C418uk4=; b=c06BUHB91VgQ+8E6/MrKgA2a2Ws/JgbUomkSp4pt16jwo+DLrjJueCCc5BjFhFGpzr lMITfegCQcQ5wwpZ9xrCjLDxfwKJkYECh5jjfxKFWMyPJ7zDRB845ZiuEWiD0K0J28JR 6qDdu5eOEHhyNba9NM4A2IzrdkvtmrA3Fvw1Jmf5ASQYlOku8Tgxep3y/eFVU6yd/8FL uK3aTxccc3g2ddBCbwrHXi9tmvujAxrhyv8TecUrUORr4dWGndfqb4k2wek96uNWHncI OqMZr7HO12zsQbyD1yv8ErnHV/9W5Ti7D8OfRmHDNLBzWZ9ExtRyi5NsDd80S5S7Vdke Bx6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=bVkJDxISQsJiDctueFKDZan7YC/pcML2RCP1C418uk4=; b=hJhLMGAiFmaFg/OE2Vveccq20fcK3JOyY1/wj4HcKoRQGk8XY3OA+zNOxThniFCemG ZfmPyL9bgtDgSH335vt1A+uOCVa4JRv3AqYq98j2tUmBcGhq5Zsek+3acjkIx5zAY4oo xFhD70fREqw7JAM6UAWnpSa9ggGEAYwX4RgPRfA1UiYgrZybRNmrKM4hrTPNXBniKy6G o8Be3asQb1sXcPmAWC5CmI3ilO7W5SNGvDtccHF44NGm/sbjPTYSdTn9ZbWAyM98gBHf lwsgwYpqdX82pU1aQWPqrU3lg2qghuGFobtl28b9vRIBmG/2/1+6W/0Es0ZGUOLhUuXH EiyQ== X-Gm-Message-State: AOAM532wIlJn3v8k+P6QlB0E6BR9nFBPd6p0s41N4Fwi8L3xafSpgMkw 4sIKUktYAM/j+b++ZTkcC/ghPll121fUcg== X-Google-Smtp-Source: ABdhPJy9FHz9OB/nJCj1/QqX5UdqbW4GlOH97zct1Rnjl33wPrJy4PQoC91FwWd9qgV9f/yz2MAUqg== X-Received: by 2002:a05:6402:1778:: with SMTP id da24mr2707480edb.385.1627562836164; Thu, 29 Jul 2021 05:47:16 -0700 (PDT) Received: from avogadro.lan ([2001:b07:6468:f312:5e2c:eb9a:a8b6:fd3e]) by smtp.gmail.com with ESMTPSA id m12sm954659ejd.21.2021.07.29.05.47.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Jul 2021 05:47:15 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 1/7] i386: assert 'cs->kvm_state' is not null Date: Thu, 29 Jul 2021 14:47:07 +0200 Message-Id: <20210729124713.208422-2-pbonzini@redhat.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210729124713.208422-1-pbonzini@redhat.com> References: <20210729124713.208422-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2a00:1450:4864:20::535; envelope-from=paolo.bonzini@gmail.com; helo=mail-ed1-x535.google.com X-Spam_score_int: -14 X-Spam_score: -1.5 X-Spam_bar: - X-Spam_report: (-1.5 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FORGED_FROMDOMAIN=0.249, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.248, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vitaly Kuznetsov Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Vitaly Kuznetsov Coverity reports potential NULL pointer dereference in get_supported_hv_cpuid_legacy() when 'cs->kvm_state' is NULL. While 'cs->kvm_state' can indeed be NULL in hv_cpuid_get_host(), kvm_hyperv_expand_features() makes sure that it only happens when KVM_CAP_SYS_HYPERV_CPUID is supported and KVM_CAP_SYS_HYPERV_CPUID implies KVM_CAP_HYPERV_CPUID so get_supported_hv_cpuid_legacy() is never really called. Add asserts to strengthen the protection against broken KVM behavior. Coverity: CID 1458243 Signed-off-by: Vitaly Kuznetsov Message-Id: <20210716115852.418293-1-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- target/i386/kvm/kvm.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 59ed8327ac..e69abe48e3 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -974,6 +974,12 @@ static struct kvm_cpuid2 *get_supported_hv_cpuid(CPUState *cs) do_sys_ioctl = kvm_check_extension(kvm_state, KVM_CAP_SYS_HYPERV_CPUID) > 0; + /* + * Non-empty KVM context is needed when KVM_CAP_SYS_HYPERV_CPUID is + * unsupported, kvm_hyperv_expand_features() checks for that. + */ + assert(do_sys_ioctl || cs->kvm_state); + /* * When the buffer is too small, KVM_GET_SUPPORTED_HV_CPUID fails with * -E2BIG, however, it doesn't report back the right size. Keep increasing @@ -1105,6 +1111,14 @@ static uint32_t hv_cpuid_get_host(CPUState *cs, uint32_t func, int reg) if (kvm_check_extension(kvm_state, KVM_CAP_HYPERV_CPUID) > 0) { cpuid = get_supported_hv_cpuid(cs); } else { + /* + * 'cs->kvm_state' may be NULL when Hyper-V features are expanded + * before KVM context is created but this is only done when + * KVM_CAP_SYS_HYPERV_CPUID is supported and it implies + * KVM_CAP_HYPERV_CPUID. + */ + assert(cs->kvm_state); + cpuid = get_supported_hv_cpuid_legacy(cs); } hv_cpuid_cache = cpuid; -- 2.31.1