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=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 CD906C43461 for ; Wed, 16 Sep 2020 21:09:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7151E20731 for ; Wed, 16 Sep 2020 21:09:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YDqOUlxc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726269AbgIPVJ5 (ORCPT ); Wed, 16 Sep 2020 17:09:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:43734 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726661AbgIPVJy (ORCPT ); Wed, 16 Sep 2020 17:09:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600290593; 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=RVdVObv8tbiDVGVAm0SCTZNM8HTzvb9fYiClqlI5+Vg=; b=YDqOUlxcH+/xbGbISfZoIsK5ni48L0Af8NKi9KV+62nWsX1xYDKrkmsHRb8+2gCryZfwyh VtRwKxTzV6oahQimTlWAD3QUDA7wRSekzIbY5MjJuWtK7GmbH3VvtjJSe1IcOxKaPT39bf 3YThZv0gG++qQrbzqWscWsluCrbaa1g= 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-465-oYobg3TyPaOR4_EN5N2vjg-1; Wed, 16 Sep 2020 17:09:51 -0400 X-MC-Unique: oYobg3TyPaOR4_EN5N2vjg-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 93725801ADC; Wed, 16 Sep 2020 21:09:50 +0000 (UTC) Received: from ovpn-66-86.rdu2.redhat.com (ovpn-66-86.rdu2.redhat.com [10.10.66.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id B345C1001281; Wed, 16 Sep 2020 21:09:49 +0000 (UTC) Message-ID: <87ded87d232d9cf87c9c64495bf9190be0e0b6e8.camel@redhat.com> Subject: Re: slab-out-of-bounds in iov_iter_revert() From: Qian Cai To: Al Viro Cc: torvalds@linux-foundation.org, vgoyal@redhat.com, miklos@szeredi.hu, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 16 Sep 2020 17:09:49 -0400 In-Reply-To: <20200911235511.GB3421308@ZenIV.linux.org.uk> References: <20200911215903.GA16973@lca.pw> <20200911235511.GB3421308@ZenIV.linux.org.uk> 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 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sat, 2020-09-12 at 00:55 +0100, Al Viro wrote: > On Fri, Sep 11, 2020 at 05:59:04PM -0400, Qian Cai wrote: > > Super easy to reproduce on today's mainline by just fuzzing for a few > > minutes > > on virtiofs (if it ever matters). Any thoughts? > > Usually happens when ->direct_IO() fucks up and reports the wrong amount > of data written/read. We had several bugs like that in the past - see > e.g. 85128b2be673 (fix nfs O_DIRECT advancing iov_iter too much). > > Had there been any recent O_DIRECT-related patches on the filesystems > involved? This is only reproducible using FUSE/virtiofs so far, so I will stare at fuse_direct_IO() until someone can beat me to it.