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 lists1p.gnu.org (lists1p.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 017E5CD37B5 for ; Mon, 11 May 2026 10:44:41 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wMO7b-0007Vr-7v; Mon, 11 May 2026 06:44:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wMO7R-0007TR-50 for qemu-devel@nongnu.org; Mon, 11 May 2026 06:44:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wMO7N-0001wO-IL for qemu-devel@nongnu.org; Mon, 11 May 2026 06:44:12 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778496244; 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=W8Ga0H8oe8kn7FIx5LyzRjRyRzZXHgIzsLmyKcPZz0o=; b=aZcPpIyUwa9b+jFiX3kzxRS2zDWFely7lcmvXNaMWQwKTbDPS81CdgoXqCpdG2PWLs+cmw dax1ah1GpB/mYjqVxtP5I3tt/HvjRlQDZ9ni7rualwp1S/SIczZ8iuE/TEh409hP4DOoK7 0NNw7pzibTFuI97LwimQGqaYGtSRXFI= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-564-6GmqnU6yOG2njzAf9uVDiw-1; Mon, 11 May 2026 06:44:01 -0400 X-MC-Unique: 6GmqnU6yOG2njzAf9uVDiw-1 X-Mimecast-MFC-AGG-ID: 6GmqnU6yOG2njzAf9uVDiw_1778496240 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 28C03195608A; Mon, 11 May 2026 10:44:00 +0000 (UTC) Received: from redhat.com (unknown [10.44.50.30]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 28C1C30001BE; Mon, 11 May 2026 10:43:56 +0000 (UTC) Date: Mon, 11 May 2026 11:43:53 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Stefano Garzarella Cc: qemu-devel@nongnu.org, Xie Yongji , qemu-stable@nongnu.org, "Michael S. Tsirkin" , DARKNAVY Subject: Re: [PATCH 1/2] libvhost-user: fix buffer overflow in virtqueue_read_indirect_desc() Message-ID: References: <20260417132645.121192-1-sgarzare@redhat.com> <20260417132645.121192-2-sgarzare@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260417132645.121192-2-sgarzare@redhat.com> User-Agent: Mutt/2.3.1 (2026-03-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-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: 2.1.29 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 Fri, Apr 17, 2026 at 03:26:44PM +0200, Stefano Garzarella wrote: > From: Stefano Garzarella > > virtqueue_read_indirect_desc() copies an indirect descriptor table > into a buffer in chunks when the table crosses a memory region > boundary. The destination is a struct vring_desc pointer but is > advanced by a byte count, so each increment moves the pointer by > read_len elements instead of read_len bytes, writing beyond the > buffer. > > Use a char pointer for the destination so that the arithmetic > advances correctly. > > While at it, change the source from a struct vring_desc pointer > to a void pointer: when the table is split across regions, > vu_gpa_to_va() can return a pointer into the middle of a descriptor, > so casting it to a struct vring_desc pointer is wrong. The pointer is > only used as a memcpy() source, so a void pointer is fine. > > Fixes: CVE-2026-6425 > Fixes: 293084a719 ("libvhost-user: Support across-memory-boundary access") > Cc: qemu-stable@nongnu.org > Reported-by: DARKNAVY > Signed-off-by: Stefano Garzarella > --- > subprojects/libvhost-user/libvhost-user.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) Reviewed-by: Daniel P. Berrangé 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 :|