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=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no 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 42B8CC433DF for ; Wed, 22 Jul 2020 04:53:15 +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 0CA4D207BB for ; Wed, 22 Jul 2020 04:53:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Askkn8bQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CA4D207BB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:32768 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jy6kk-0002RN-Bv for qemu-devel@archiver.kernel.org; Wed, 22 Jul 2020 00:53:14 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54174) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jy6k3-000219-4O for qemu-devel@nongnu.org; Wed, 22 Jul 2020 00:52:31 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:58765 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jy6k0-0004AM-Ni for qemu-devel@nongnu.org; Wed, 22 Jul 2020 00:52:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595393547; 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: in-reply-to:in-reply-to:references:references; bh=STZrqDrbzeeluizI6/yn1XLp7GJSAlpC12VVmj0kCng=; b=Askkn8bQrEYSi+2Pwq0TUDgpeqS230GJTe/GjyVjlnymULXCRvQjuQZFzRFKgPlFo5XIMl wYJimFPil5Jbe3wQasag2lfJUxrJ1z1SvCatJKKLOeF/NSDe3XvH5oedd9sVQPV2vFDxoV FclgrICBrh82VU47QAriFxMZ/2lUjwQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-347-Gd6qNzZfPe6E2fLu5KdHbQ-1; Wed, 22 Jul 2020 00:52:23 -0400 X-MC-Unique: Gd6qNzZfPe6E2fLu5KdHbQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 19A458005B0; Wed, 22 Jul 2020 04:52:22 +0000 (UTC) Received: from kaapi (ovpn-112-29.phx2.redhat.com [10.3.112.29]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E63F874F6B; Wed, 22 Jul 2020 04:52:18 +0000 (UTC) Date: Wed, 22 Jul 2020 10:22:15 +0530 (IST) From: P J P X-X-Sender: pjp@kaapi To: Jason Wang Subject: Re: [PATCH v3] e1000e: using bottom half to send packets In-Reply-To: <307795f9-70bb-b83b-6110-da2c923e4dc2@redhat.com> Message-ID: References: <20200721151728.112395-1-liq3ea@163.com> <307795f9-70bb-b83b-6110-da2c923e4dc2@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/mixed; boundary="-1463810047-1603545069-1595393541=:4380" Received-SPF: pass client-ip=207.211.31.81; envelope-from=ppandit@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/21 23:34:34 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: dmitry.fleytman@gmail.com, Li Qiang , liq3ea@gmail.com, qemu-devel@nongnu.org, alxndr@bu.edu, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---1463810047-1603545069-1595393541=:4380 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT +-- On Wed, 22 Jul 2020, Jason Wang wrote --+ | On 2020/7/21 下午11:17, Li Qiang wrote: | > Alexander Bulekov reported a UAF bug related e1000e packets send. | > | > -->https://bugs.launchpad.net/qemu/+bug/1886362 | > | > This is because the guest trigger a e1000e packet send and set the | > data's address to e1000e's MMIO address. So when the e1000e do DMA | > it will write the MMIO again and trigger re-entrancy and finally | > causes this UAF. | > | > Paolo suggested to use a bottom half whenever MMIO is doing complicate | > things in here: | > -->https://lists.nongnu.org/archive/html/qemu-devel/2020-07/msg03342.html | > | > Reference here: | > 'The easiest solution is to delay processing of descriptors to a bottom | > half whenever MMIO is doing something complicated. This is also better | > for latency because it will free the vCPU thread more quickly and leave | > the work to the I/O thread.' | > | > This patch fixes this UAF. | > | > Reported-by: Alexander Bulekov | > Signed-off-by: Li Qiang | > --- | > Change since v2: | > 1. Add comments for the tx bh schdule when VM resumes | > 2. Leave the set ics code in 'e1000e_start_xmit' | > 3. Cancel the tx bh and reset tx_waiting in e1000e_core_reset | | | So based on our discussion this is probably not sufficient. It solves the | issue TX re-entrancy but not RX (e.g RX DMA to RDT?) Or is e1000e's RX is | reentrant? Fixes: (CVE-2020-15859) -> https://bugzilla.redhat.com/show_bug.cgi?id=1859168 Thank you. -- Prasad J Pandit / Red Hat Product Security Team 8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D ---1463810047-1603545069-1595393541=:4380--