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=-15.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 1E01BC4361B for ; Thu, 10 Dec 2020 18:04:24 +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 7ABB823B26 for ; Thu, 10 Dec 2020 18:04:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7ABB823B26 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]:50434 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1knQIg-0003IP-DJ for qemu-devel@archiver.kernel.org; Thu, 10 Dec 2020 13:04:22 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:60418) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1knQFH-0001iQ-1e for qemu-devel@nongnu.org; Thu, 10 Dec 2020 13:00:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:20485) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1knQFA-0000Ug-94 for qemu-devel@nongnu.org; Thu, 10 Dec 2020 13:00:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607623243; 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=eEv02TkJ3ZxJp4sNOjbr3fw7o9eG8eOgMJNISH+HE7A=; b=O+20qrDB3kseIXBLLaaUisT6cZUO23dPmDfQI74jFXIwuZc778IP1QvlO86DwzkLEAmfIp zeppSifyN6m76Ai5V1EoXS7mxiPKuSfVycCmFyDwou3ITR70qHlhiLXPLiP45IktTueNGZ 2gfK8c6HVCicnv+YQjlS9qRRXW92XKA= 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-557-dIxifL-nO2ueqh8tL92yAg-1; Thu, 10 Dec 2020 13:00:41 -0500 X-MC-Unique: dIxifL-nO2ueqh8tL92yAg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2B8C8835DE4; Thu, 10 Dec 2020 18:00:40 +0000 (UTC) Received: from work-vm (ovpn-113-66.ams2.redhat.com [10.36.113.66]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BE65E60BFA; Thu, 10 Dec 2020 18:00:13 +0000 (UTC) Date: Thu, 10 Dec 2020 18:00:10 +0000 From: "Dr. David Alan Gilbert" To: Alex Chen Subject: Re: [PATCH] virtiofsd: Fix potential NULL pointer dereference in virtio_send_msg() Message-ID: <20201210180010.GG3629@work-vm> References: <20201210151426.89244-1-alex.chen@huawei.com> MIME-Version: 1.0 In-Reply-To: <20201210151426.89244-1-alex.chen@huawei.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=216.205.24.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: qemu-trivial@nongnu.org, qemu-devel@nongnu.org, stefanha@redhat.com, zhang.zhanghailiang@huawei.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Alex Chen (alex.chen@huawei.com) wrote: > The 'ch' will be NULL in the following stack: > send_notify_iov()->fuse_send_msg()->virtio_send_msg(), > so we should check 'ch' is valid before dereferencing it > > Reported-by: Euler Robot > Signed-off-by: Alex Chen Please check, but I don't think we can currently hit this because we never call send_notify_iov - it's currently called by fuse_lowlevel_notify_inval_entry, inval_inode, and fuse_lowlevel_notify_poll - but I don't think those are called anywhere. In that case, probably the best fix is to remove those until we put notify back in. Dave > --- > tools/virtiofsd/fuse_virtio.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c > index 623812c432..31b2187a15 100644 > --- a/tools/virtiofsd/fuse_virtio.c > +++ b/tools/virtiofsd/fuse_virtio.c > @@ -205,6 +205,8 @@ static void copy_iov(struct iovec *src_iov, int src_count, > int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch, > struct iovec *iov, int count) > { > + assert(ch); > + > FVRequest *req = container_of(ch, FVRequest, ch); > struct fv_QueueInfo *qi = ch->qi; > VuDev *dev = &se->virtio_dev->dev; > -- > 2.19.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK