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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5E248C43613 for ; Thu, 20 Jun 2019 18:27:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38D9920656 for ; Thu, 20 Jun 2019 18:27:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728307AbfFTS12 (ORCPT ); Thu, 20 Jun 2019 14:27:28 -0400 Received: from mga05.intel.com ([192.55.52.43]:56248 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726408AbfFTSFD (ORCPT ); Thu, 20 Jun 2019 14:05:03 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jun 2019 11:05:02 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,397,1557212400"; d="scan'208";a="243714870" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.137]) by orsmga001.jf.intel.com with ESMTP; 20 Jun 2019 11:05:01 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id 9ABAE300FFA; Thu, 20 Jun 2019 11:05:01 -0700 (PDT) From: Andi Kleen To: ehankland@google.com Cc: linux-kernel@vger.kernel.org, linux-kvm@vger.kernel.org Subject: Re: [PATCH v1] KVM: x86: PMU Whitelist References: Date: Thu, 20 Jun 2019 11:05:01 -0700 In-Reply-To: (Eric Hankland's message of "Wed, 22 May 2019 15:23:00 -0700") Message-ID: <877e9g9lpu.fsf@firstfloor.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Eric Hankland writes: > > +int kvm_vcpu_ioctl_set_pmu_whitelist(struct kvm_vcpu *vcpu, > + struct kvm_pmu_whitelist __user *whtlst) > +{ > + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); > + struct kvm_pmu_whitelist *old = pmu->whitelist; > + struct kvm_pmu_whitelist *new = NULL; > + struct kvm_pmu_whitelist tmp; > + int r; > + size_t size; > + > + r = -EFAULT; > + if (copy_from_user(&tmp, whtlst, sizeof(struct kvm_pmu_whitelist))) > + goto err; > + > + size = sizeof(tmp) + sizeof(tmp.events[0]) * tmp.num_events; > + new = kvzalloc(size, GFP_KERNEL_ACCOUNT); Consider what happens when tmp.num_events is large enough to wrap size. I suspect that's a kernel exploit as written. Also don't you need to copy tmp to new? -Andi