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=-3.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 C9C16C4363A for ; Fri, 30 Oct 2020 12:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6403120729 for ; Fri, 30 Oct 2020 12:00:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="h/93EuGC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726120AbgJ3MAp (ORCPT ); Fri, 30 Oct 2020 08:00:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:45257 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725808AbgJ3MAp (ORCPT ); Fri, 30 Oct 2020 08:00:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604059243; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rNq2Zfxvzm57VdYBL3I2bff9Y+07X81lkXYsCB6Of6k=; b=h/93EuGCdaLpfNGLwyaEbBDU2u0niZMXwv92xf++X3BNpxGp6Gz/x+XrZnkxMbIj9mjtFu hPsnoN1pNcpQXWyAyCU1hJf7RbVWVSYNUZ8EzpdyuBFa9WPAFRJTOBpwxq8AM/x9CLhDpX 7lGNqqJIBRmvqDzyqKHI/CRqOxF4IEU= 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-285-T42lQ-NzP2iqpOaPm4nVfw-1; Fri, 30 Oct 2020 08:00:41 -0400 X-MC-Unique: T42lQ-NzP2iqpOaPm4nVfw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AB51110866C3; Fri, 30 Oct 2020 12:00:40 +0000 (UTC) Received: from ovpn-66-212.rdu2.redhat.com (ovpn-66-212.rdu2.redhat.com [10.10.66.212]) by smtp.corp.redhat.com (Postfix) with ESMTP id E279B1001281; Fri, 30 Oct 2020 12:00:04 +0000 (UTC) Message-ID: <8b57dd7972f54fcf271a5790696cbd6c950269ff.camel@redhat.com> Subject: Re: WARN_ON(fuse_insert_writeback(root, wpa)) in tree_insert() From: Qian Cai To: Miklos Szeredi Cc: Vivek Goyal , Stefan Hajnoczi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, virtio-fs-list Date: Fri, 30 Oct 2020 08:00:03 -0400 In-Reply-To: References: <89f0dbf6713ebd44ec519425e3a947e71f7aed55.camel@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2020-10-29 at 16:20 +0100, Miklos Szeredi wrote: > On Thu, Oct 29, 2020 at 4:02 PM Qian Cai wrote: > > On Wed, 2020-10-07 at 16:08 -0400, Qian Cai wrote: > > > Running some fuzzing by a unprivileged user on virtiofs could trigger the > > > warning below. The warning was introduced not long ago by the commit > > > c146024ec44c ("fuse: fix warning in tree_insert() and clean up writepage > > > insertion"). > > > > > > From the logs, the last piece of the fuzzing code is: > > > > > > fgetxattr(fd=426, name=0x7f39a69af000, value=0x7f39a8abf000, size=1) > > > > I can still reproduce it on today's linux-next. Any idea on how to debug it > > further? > > Can you please try the attached patch? So far so good. I'll keep running it over the weekend to be a little bit sure. It was taking a while to reproduce.