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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 4C1EEC4161D for ; Thu, 11 Oct 2018 13:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0936920652 for ; Thu, 11 Oct 2018 13:44:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="o6b7IsJe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0936920652 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728488AbeJKVLO (ORCPT ); Thu, 11 Oct 2018 17:11:14 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:36858 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727316AbeJKVLO (ORCPT ); Thu, 11 Oct 2018 17:11:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=v8819EttYxOvTmgTpUHdv0GZSNWbIsLeBMFrLt7b8AM=; b=o6b7IsJeWiGyakuspAevLxBak 7yhcppPoNs7yXoVoAnC5q02WjkqlDyohh9XzEq//nZTfpJ5fYciQBVMTfIEKalspMUfpRayCz67+D 4u/EHAVGK0pzXoHetr62J8Ww6c3LsPLxGskpVB7CE0TD1ZR/FsPqlFC/L1W5I9fBJFh3+78SErEzy KLVBpBqXfAYSmoWUpyiSHUA57HjrYMLKBi5WQKB5LN483i8fhc1DJvdjAP2XgYLAuEoblaCsV7z1M E+GJBudXdHKVOXYi8/zI2iwgXKsY86KOPs1MpRWw+rHsgfyZiZqhoAeKmD0DKeubWsReoUYB1r/mV T2goiVs9Q==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gAbFt-00087P-4W; Thu, 11 Oct 2018 13:43:57 +0000 Date: Thu, 11 Oct 2018 06:43:56 -0700 From: Christoph Hellwig To: "Darrick J. Wong" Cc: david@fromorbit.com, sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, Amir Goldstein , linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: Re: [PATCH 04/25] vfs: strengthen checking of file range inputs to generic_remap_checks Message-ID: <20181011134356.GD23424@infradead.org> References: <153923113649.5546.9840926895953408273.stgit@magnolia> <153923116686.5546.8711942394464060950.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153923116686.5546.8711942394464060950.stgit@magnolia> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Wed, Oct 10, 2018 at 09:12:46PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > File range remapping, if allowed to run past the destination file's EOF, > is an optimization on a regular file write. Regular file writes that > extend the file length are subject to various constraints which are not > checked by range cloning. > > This is a correctness problem because we're never allowed to touch > ranges that the page cache can't support (s_maxbytes); we're not > supposed to deal with large offsets (MAX_NON_LFS) if O_LARGEFILE isn't > set; and we must obey resource limits (RLIMIT_FSIZE). > > Therefore, add these checks to the new generic_remap_checks function so > that we curtail unexpected behavior. > > Signed-off-by: Darrick J. Wong > Reviewed-by: Amir Goldstein Looks good, Reviewed-by: Christoph Hellwig