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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 01D26FCC9DE for ; Tue, 10 Mar 2026 09:04:57 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vzt11-0007HJ-Pc; Tue, 10 Mar 2026 05:04:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vzt0u-0007Gr-KL for qemu-devel@nongnu.org; Tue, 10 Mar 2026 05:04:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vzt0p-0008OB-3q for qemu-devel@nongnu.org; Tue, 10 Mar 2026 05:04:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1773133461; h=from:from:reply-to: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=Ny9luQVSX+i34yZm4gF9ds4AYSGfNIsLIYl8Upc740I=; b=Z0+TjPeWulYlb+VDJWZ7fIc+uLqww5+c/S44OdAbAPY5Z0ZmA8Ode3d8zLmPRfk7n5gnGW SNb+zM66qTptDxScG73EnCfuFlvgQJuL6Hdkyuwby/bvC8NccYFFwewCu6aXLGfMEq9gDB zIeKf+POhUFA+ifcUMtTFZi+Bs95SDs= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-207-LeeKbdcMPMa3N0qCFvvPwA-1; Tue, 10 Mar 2026 05:04:19 -0400 X-MC-Unique: LeeKbdcMPMa3N0qCFvvPwA-1 X-Mimecast-MFC-AGG-ID: LeeKbdcMPMa3N0qCFvvPwA_1773133458 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8B23418005BD; Tue, 10 Mar 2026 09:04:18 +0000 (UTC) Received: from redhat.com (unknown [10.44.33.213]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id AAF611956095; Tue, 10 Mar 2026 09:04:15 +0000 (UTC) Date: Tue, 10 Mar 2026 09:04:12 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Paolo Bonzini Cc: qemu-devel@nongnu.org, mcascell@redhat.com, security@1seal.org Subject: Re: [PATCH] hyperv/syndbg: check length returned by cpu_physical_memory_map() [Fixes: CVE-2026-3842] Message-ID: References: <20260309190155.80619-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260309190155.80619-1-pbonzini@redhat.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_VALIDITY_RPBL_BLOCKED=0.819, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.903, SPF_HELO_PASS=-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: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Mar 09, 2026 at 08:01:44PM +0100, Paolo Bonzini wrote: > If cpu_physical_memory_map() returns a length shorter than the one > that was passed into the function, writing the full out_len bytes > causes an access beyond the memory allocated to the guest; or in > the case of the MMIO bounce buffer, an out-of-bounds access in a > heap-allocated object. > > Add a check similar to the one already in handle_send_msg(), > and take the occasion to remove repeated computations of > recv_byte_count + UDP_PKT_HEADER_SIZE and clarify that the > code does not write past out_len bytes. > Can you add Fixes: CVE-2026-3842 > Reported-by: Oleh Konko > Reviewed-by: Daniel P. Berrangé > Signed-off-by: Paolo Bonzini > --- > hw/hyperv/syndbg.c | 23 +++++++++++------------ > 1 file changed, 11 insertions(+), 12 deletions(-) With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|