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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 C27C0C19759 for ; Thu, 1 Aug 2019 16:33:24 +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 8BBD120679 for ; Thu, 1 Aug 2019 16:33:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8BBD120679 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]:57592 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1htE15-0005f8-PU for qemu-devel@archiver.kernel.org; Thu, 01 Aug 2019 12:33:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54801) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1htDzz-00054E-RE for qemu-devel@nongnu.org; Thu, 01 Aug 2019 12:32:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1htDzy-0003m9-UD for qemu-devel@nongnu.org; Thu, 01 Aug 2019 12:32:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43088) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1htDzy-0003lW-PI for qemu-devel@nongnu.org; Thu, 01 Aug 2019 12:32:14 -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 CFCF2314355F for ; Thu, 1 Aug 2019 16:32:12 +0000 (UTC) Received: from localhost (ovpn-116-232.ams2.redhat.com [10.36.116.232]) by smtp.corp.redhat.com (Postfix) with ESMTP id 588D75D9CA; Thu, 1 Aug 2019 16:32:07 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org, virtio-fs@redhat.com Date: Thu, 1 Aug 2019 17:32:06 +0100 Message-Id: <20190801163206.7906-1-stefanha@redhat.com> MIME-Version: 1.0 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 [10.5.110.49]); Thu, 01 Aug 2019 16:32:12 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [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: "Dr. David Alan Gilbert" , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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 --- contrib/virtiofsd/passthrough_ll.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passt= hrough_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); =20 res =3D close(dup(lo_fi_fd(req, fi))); - fuse_reply_err(req, res =3D=3D -1 ? errno : 0); - lo_inode_put(lo_data(req), &inode); + fuse_reply_err(req, res =3D=3D -1 ? errno : 0); } =20 static void lo_fsync(fuse_req_t req, fuse_ino_t ino, int datasync, --=20 2.21.0