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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C0C0C4332F for ; Tue, 18 Oct 2022 20:44:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229569AbiJRUog (ORCPT ); Tue, 18 Oct 2022 16:44:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229718AbiJRUoe (ORCPT ); Tue, 18 Oct 2022 16:44:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0E8AFAD3 for ; Tue, 18 Oct 2022 13:44:28 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CE569B8210D for ; Tue, 18 Oct 2022 20:44:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B728C433D7; Tue, 18 Oct 2022 20:44:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666125865; bh=mgOex7y3sOnBUo89KQHwT+Tu6LykPf5SHLU0nCKUTas=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R48A+rKr8aqP1+9XdhrzOykTv1So2wIkwLP9Q7t9Fjwmp3TEvV3Xi6wdfm/8D8Um/ mTdCkLO9XuPFz1JVNltU8uLC5aDr44iQM0TEVf+RiUBawCA+fYyB4jdbWEuEJbxMQJ sQj36nopr5Fp7oYtzcRvl2omZlHrZLuBAwH+/pJIx/D1EnFvlV0a8mU3ecLR4KUQv/ a2D8IedNy3fIGSIeC9WpvFRDl0Tq5DN5tLoBHf7w/sl2V/V4435RLyOfCYc+uGtN9t vVDJpOu9XlkK5DcBOwIVGFmVL0u2Yks6xTkhWGkopo2yFfdRPFIBvyxM6fGfsHF1UD ETnl6hemB/y2A== Date: Tue, 18 Oct 2022 13:44:25 -0700 From: "Darrick J. Wong" To: bugzilla-daemon@kernel.org Cc: linux-xfs@vger.kernel.org Subject: Re: [Bug 216563] [xfstests generic/113] memcpy: detected field-spanning write (size 32) of single field "efdp->efd_format.efd_extents" at fs/xfs/xfs_extfree_item.c:693 (size 16) Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sun, Oct 09, 2022 at 10:42:29PM +0000, bugzilla-daemon@kernel.org wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=216563 > > --- Comment #3 from Dave Chinner (david@fromorbit.com) --- > On Sun, Oct 09, 2022 at 10:08:46AM -0700, Darrick J. Wong wrote: > > On Sun, Oct 09, 2022 at 11:59:13AM +0000, bugzilla-daemon@kernel.org wrote: > > > https://bugzilla.kernel.org/show_bug.cgi?id=216563 > > > > > > Bug ID: 216563 > > > Summary: [xfstests generic/113] memcpy: detected field-spanning > > > write (size 32) of single field > > > "efdp->efd_format.efd_extents" at > > > fs/xfs/xfs_extfree_item.c:693 (size 16) > > > Product: File System > > > Version: 2.5 > > > Kernel Version: v6.1-rc0 > > > Hardware: All > > > OS: Linux > > > Tree: Mainline > > > Status: NEW > > > Severity: normal > > > Priority: P1 > > > Component: XFS > > > Assignee: filesystem_xfs@kernel-bugs.kernel.org > > > Reporter: zlang@redhat.com > > > Regression: No > > > > > > I xfstests generic/113 hit below kernel warning [1] on xfs with 64k > > directory > > > block size (-n size=65536). It's reproducible for me, and the last time I > > > reproduce this bug on linux v6.0+ which HEAD= ... > > > > > > commit e8bc52cb8df80c31c73c726ab58ea9746e9ff734 > > > Author: Linus Torvalds > > > Date: Fri Oct 7 17:04:10 2022 -0700 > > > > > > Merge tag 'driver-core-6.1-rc1' of > > > git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core > > > > > > I hit this issue on xfs with 64k directory block size 3 times(aarch64, > > x86_64 > > > and ppc64le), and once on xfs with 1k blocksize (aarch64). > > > > > > > > > [1] > > > [ 4328.023770] run fstests generic/113 at 2022-10-08 11:57:42 > > > [ 4330.104632] XFS (sda3): EXPERIMENTAL online scrub feature in use. Use at > > > your own risk! > > > [ 4333.094807] XFS (sda3): Unmounting Filesystem > > > [ 4333.934996] XFS (sda3): Mounting V5 Filesystem > > > [ 4333.973061] XFS (sda3): Ending clean mount > > > [ 4335.457595] XFS (sda3): EXPERIMENTAL online scrub feature in use. Use at > > > your own risk! > > > [ 4338.564849] XFS (sda3): Unmounting Filesystem > > > [ 4339.391848] XFS (sda3): Mounting V5 Filesystem > > > [ 4339.430908] XFS (sda3): Ending clean mount > > > [ 4340.100364] XFS (sda3): EXPERIMENTAL online scrub feature in use. Use at > > > your own risk! > > > [ 4343.379506] XFS (sda3): Unmounting Filesystem > > > [ 4344.195036] XFS (sda3): Mounting V5 Filesystem > > > [ 4344.232984] XFS (sda3): Ending clean mount > > > [ 4345.190073] XFS (sda3): EXPERIMENTAL online scrub feature in use. Use at > > > your own risk! > > > [ 4348.198562] XFS (sda3): Unmounting Filesystem > > > [ 4349.065061] XFS (sda3): Mounting V5 Filesystem > > > [ 4349.104995] XFS (sda3): Ending clean mount > > > [ 4350.118883] XFS (sda3): EXPERIMENTAL online scrub feature in use. Use at > > > your own risk! > > > [ 4353.233555] XFS (sda3): Unmounting Filesystem > > > [ 4354.093530] XFS (sda3): Mounting V5 Filesystem > > > [ 4354.135975] XFS (sda3): Ending clean mount > > > [ 4354.337550] ------------[ cut here ]------------ > > > [ 4354.342354] memcpy: detected field-spanning write (size 32) of single > > field > > > "efdp->efd_format.efd_extents" at fs/xfs/xfs_extfree_item.c:693 (size 16) > > > [ 4354.355820] WARNING: CPU: 7 PID: 899243 at fs/xfs/xfs_extfree_item.c:693 > > > xfs_efi_item_relog+0x1fc/0x270 [xfs] > > > > I think this is caused by an EF[ID] with ef[id]_nextents > 1, since the > > structure definition is: > > > > typedef struct xfs_efd_log_format { > > uint16_t efd_type; /* efd log item type */ > > uint16_t efd_size; /* size of this item */ > > uint32_t efd_nextents; /* # of extents freed */ > > uint64_t efd_efi_id; /* id of corresponding efi */ > > xfs_extent_t efd_extents[1]; /* array of extents freed */ > > } xfs_efd_log_format_t; > > > > Yuck, an array[1] that is actually a VLA! > > Always been the case; the comment above both EFI and EFD definitions > state this directly: > > /* > * This is the structure used to lay out an efi log item in the > * log. The efi_extents field is a variable size array whose > * size is given by efi_nextents. > */ > > The EFI/EFD support recording multiple extents being freed in a > single intent. The idea behind this originally was that all the > extents being freed in a single transaction would be recorded in the > same EFI (i.e. XFS_ITRUNC_MAX_EXTENTS) and the EFI and EFD could > then be relogged as progress freeing those extents is made after the > BMBT modifications were committed... > > > I guess we're going to have to turn that into a real VLA, and adjust the > > xfs_ondisk.h macros to match? > > > > What memory sanitizer kconfig option enables this, anyway? > > 54d9469bc515 fortify: Add run-time WARN for cross-field memcpy() > > CONFIG_FORTIFY_SOURCE=y, committed in 6.0-rc2. > > It effectively ignores flex arrays defined with [], but sees > anything defined with [1] as a fixed size array of known size and so > issues a warning when it's actually used as a flex array. > > unsafe_memcpy() could be a temporary solution, given we know the > code works fine as it stands... Annoyingly, this now triggers fstests failures on xfs/436 when log recovery tries to memcpy a BUI log item: ------------[ cut here ]------------ memcpy: detected field-spanning write (size 48) of single field "dst_bui_fmt" at fs/xfs/xfs_bmap_item.c:628 (size 16) WARNING: CPU: 0 PID: 20925 at fs/xfs/xfs_bmap_item.c:628 xlog_recover_bui_commit_pass2+0x124/0x160 [xfs] Here we're using struct xfs_map_extent bui_extents[] for the VLA, so I think this means the memcpy fortify macros aren't detecting the VLAs correctly at all. --D > Cheers, > > Dave. > > -- > You may reply to this email to add a comment. > > You are receiving this mail because: > You are watching the assignee of the bug.