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=-9.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 BD691C433E0 for ; Mon, 27 Jul 2020 20:16:16 +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 85BC420729 for ; Mon, 27 Jul 2020 20:16:16 +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="Y7dOEqVc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85BC420729 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]:45608 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k09Xj-0000HG-Ps for qemu-devel@archiver.kernel.org; Mon, 27 Jul 2020 16:16:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54860) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k09Vo-0006uz-Op for qemu-devel@nongnu.org; Mon, 27 Jul 2020 16:14:16 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:52585 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 1k09Vn-00080N-4z for qemu-devel@nongnu.org; Mon, 27 Jul 2020 16:14:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595880854; 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=HwqyojKaNFiDvTHphjix7QdNCXyf6E4WoS4snBduGCQ=; b=Y7dOEqVcJL4/nv2D8jpC3fGyAqOOaURwv8yFtE0/LIej3Q+WHINzlOL2djSjh4ytZbRfts W/E53XMoAp1imm5maKGPMzG+aiSHUU/BXRBJLVz8eMxRR96Z/tT8KFzjUXnlVpAzWclHJq ybzl5iQ5Eeyy2WBdtwk5BUrNz7HoQ9s= 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-103-1Ikx3IafMMSb1Bl56WSBrw-1; Mon, 27 Jul 2020 16:14:07 -0400 X-MC-Unique: 1Ikx3IafMMSb1Bl56WSBrw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 11168805723; Mon, 27 Jul 2020 20:14:06 +0000 (UTC) Received: from [10.10.118.248] (ovpn-118-248.rdu2.redhat.com [10.10.118.248]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CEEF610013C0; Mon, 27 Jul 2020 20:14:01 +0000 (UTC) Subject: Re: [PATCH v4 15/21] migration/block-dirty-bitmap: relax error handling in incoming part To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20200727194236.19551-1-vsementsov@virtuozzo.com> <20200727194236.19551-16-vsementsov@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: Date: Mon, 27 Jul 2020 15:14:00 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200727194236.19551-16-vsementsov@virtuozzo.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/27 03:37:14 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=unavailable 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: kwolf@redhat.com, fam@euphon.net, quintela@redhat.com, qemu-devel@nongnu.org, dgilbert@redhat.com, stefanha@redhat.com, den@openvz.org, mreitz@redhat.com, jsnow@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/27/20 2:42 PM, Vladimir Sementsov-Ogievskiy wrote: > Bitmaps data is not critical, and we should not fail the migration (or > use postcopy recovering) because of dirty-bitmaps migration failure. > Instead we should just lose unfinished bitmaps. > > Still we have to report io stream violation errors, as they affect the > whole migration stream. > I'm amending this to also add: While touching this, tighten code that was previously blindly calling malloc on a size read from the migration stream, as a corrupted stream (perhaps from a malicious user) should not be able to convince us to allocate an inordinate amount of memory. > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > migration/block-dirty-bitmap.c | 164 +++++++++++++++++++++++++-------- > 1 file changed, 127 insertions(+), 37 deletions(-) > > @@ -650,15 +695,46 @@ static int dirty_bitmap_load_bits(QEMUFile *f, DBMLoadState *s) > > if (s->flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) { > trace_dirty_bitmap_load_bits_zeroes(); > - bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte, nr_bytes, > - false); > + if (!s->cancelled) { > + bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte, > + nr_bytes, false); > + } > } else { > size_t ret; > - uint8_t *buf; > + g_autofree uint8_t *buf = NULL; > uint64_t buf_size = qemu_get_be64(f); > - uint64_t needed_size = > - bdrv_dirty_bitmap_serialization_size(s->bitmap, > - first_byte, nr_bytes); > + uint64_t needed_size; > + > + /* > + * Actual check for buf_size is done a bit later. We can't do it in s/Actual/The actual/ > + * cancelled mode as we don't have the bitmap to check the constraints > + * (so, we do allocate buffer and read prior to the check). On the other > + * hand, we shouldn't blindly g_malloc the number from the stream. > + * Actually one chunk should not be larger thatn CHUNK_SIZE. Let's allow than > + * a bit larger (which means that bitmap migration will fail anyway and > + * the whole migration will most probably fail soon due to broken > + * stream). > + */ > + if (buf_size > 10 * CHUNK_SIZE) { > + error_report("Bitmap migration stream requests too large buffer " > + "size to allocate"); Bitmap migration stream buffer allocation request is too large I'll make those touchups. Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org