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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 ED6EEC433FF for ; Thu, 1 Aug 2019 16:39:06 +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 82BD920838 for ; Thu, 1 Aug 2019 16:39:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82BD920838 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]:57654 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1htE6a-0000w9-Mg for qemu-devel@archiver.kernel.org; Thu, 01 Aug 2019 12:39:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55701) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1htE4R-0008P7-VV for qemu-devel@nongnu.org; Thu, 01 Aug 2019 12:36:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1htE4R-0005tr-3H for qemu-devel@nongnu.org; Thu, 01 Aug 2019 12:36:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35628) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1htE4Q-0005pq-TZ for qemu-devel@nongnu.org; Thu, 01 Aug 2019 12:36:51 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 25C3630C4AD0 for ; Thu, 1 Aug 2019 16:36:43 +0000 (UTC) Received: from work-vm (ovpn-117-184.ams2.redhat.com [10.36.117.184]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 766565D9E5; Thu, 1 Aug 2019 16:36:36 +0000 (UTC) Date: Thu, 1 Aug 2019 17:36:34 +0100 From: "Dr. David Alan Gilbert" To: Stefan Hajnoczi Message-ID: <20190801163634.GQ2773@work-vm> References: <20190801163206.7906-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190801163206.7906-1-stefanha@redhat.com> User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Thu, 01 Aug 2019 16:36:43 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH] virtiofsd: fix req use-after-free in lo_flush() 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: virtio-fs@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Stefan Hajnoczi (stefanha@redhat.com) wrote: > Isn't it funny that a commit trying to fix use-after-free introduced its > own use-after-free? > > fuse_reply_err() frees the request so we cannot call lo_data(req) > afterwards. > > Fixes: a5081fc6fc3603671383616127b3a5e169cf64ed > ("virtiofsd: introduce inode refcount to prevent use-after-free") > Signed-off-by: Stefan Hajnoczi Squashed into the top. Dave > --- > contrib/virtiofsd/passthrough_ll.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c > index ee8627446a..a81c01d0d1 100644 > --- a/contrib/virtiofsd/passthrough_ll.c > +++ b/contrib/virtiofsd/passthrough_ll.c > @@ -1969,9 +1969,8 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi) > pthread_mutex_unlock(&inode->plock_mutex); > > res = close(dup(lo_fi_fd(req, fi))); > - fuse_reply_err(req, res == -1 ? errno : 0); > - > lo_inode_put(lo_data(req), &inode); > + fuse_reply_err(req, res == -1 ? errno : 0); > } > > static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, > -- > 2.21.0 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK