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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC895C25B76 for ; Tue, 11 Jun 2024 09:14:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7EACE6B0088; Tue, 11 Jun 2024 05:14:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 79A9C6B008A; Tue, 11 Jun 2024 05:14:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 662066B008C; Tue, 11 Jun 2024 05:14:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 4A4E06B0088 for ; Tue, 11 Jun 2024 05:14:23 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id E400F412C8 for ; Tue, 11 Jun 2024 09:14:22 +0000 (UTC) X-FDA: 82218046764.18.634A7D6 Received: from mail-yw1-f172.google.com (mail-yw1-f172.google.com [209.85.128.172]) by imf11.hostedemail.com (Postfix) with ESMTP id 1BC2840016 for ; Tue, 11 Jun 2024 09:14:20 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=ia6Sp6eX; spf=pass (imf11.hostedemail.com: domain of hughd@google.com designates 209.85.128.172 as permitted sender) smtp.mailfrom=hughd@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1718097261; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=EqcTAILBWMoM2RnR2kpmmEiseDcW1gScP97iUYXzTvE=; b=hhU9y9Nfcw7zt3euHJ7v8yLxOO3ESU+fR1LZMHjC/enafAkJeRBhImYc5/lEVqTvo6rnpN f+53TxNQSTDvp5zQ+lE/AlNopV3HtLfTm5/IScaHetbtbjx4Rm5w7tkR7FRYwyhnlwajTf fL8yylgZNPWroSZ793Kj3PLHu90Fqwo= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=ia6Sp6eX; spf=pass (imf11.hostedemail.com: domain of hughd@google.com designates 209.85.128.172 as permitted sender) smtp.mailfrom=hughd@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1718097261; a=rsa-sha256; cv=none; b=lpI2j4zaJ2aRSoy5JyEWTq6cAjRdiDsPawh6lyitVURgFf23PAYHnijeQMlJNd5MC2aY5n dycY3QuXsIX5T3eO1JrvyAgLDYafbNq0ZugaQGVHyvWr/MET4tNF1vuMDvpWJpnQsKcqJP vXysPSCiUhtktnisqHCh6h0YC2d6lRI= Received: by mail-yw1-f172.google.com with SMTP id 00721157ae682-62cf4d32c68so10180947b3.1 for ; Tue, 11 Jun 2024 02:14:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1718097260; x=1718702060; darn=kvack.org; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=EqcTAILBWMoM2RnR2kpmmEiseDcW1gScP97iUYXzTvE=; b=ia6Sp6eXHmtQmOJeXNu8quZEy5PRnqCl6n55laRX/bBthLbmdWorsPBiZNdtH+oRRF sn8pSDNRgyenseghlO82KpNxtU5634AhV+A/ikevnQWSRW78Urs4IQJZhcgeFAlW/l7I luMv/7wpvHPYuSj7HdkDDRP0V66QSgC9+SoJGu4fRItIScZPDCUiiVLNCeOy8e/6x+Rc pG46afmnE/V0GUg9gLvuqb3d2+7esDeg3pcYh54CsRlRWlm+UyadVvZtnnjJxA9SF78J WGSdn30TM5udoZKhKdbVLAtI5EM48deybUcLPsnnWd+ewrt7dLti0V77BGAZKqlW7NjB vy1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718097260; x=1718702060; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=EqcTAILBWMoM2RnR2kpmmEiseDcW1gScP97iUYXzTvE=; b=rYGkz4i8F7ZXVksm/4HkmeuVO6tlo4xia9Q9AnNA2kVs+Xx7SqJGFG4RY+DDR6tAWn YS8YekvnSZxm8WiSfY9dNqYFtTKJ6TqMaEy0uqZHd1Pwgst0riYXfWO0QRo9N0sM9as6 zZGn2J1rB+tUrtS3LuEXhg4NOc5XJq9dXR/inQaUm72iOcJ9k24/qZaVGqIz6oYKJTIq ujOw0irj42r7ZF2g1BGbi1ZxbK9cIhuWoRRaWBXwOGARFkfymH6ayOP84Ola0RXccM3P XVwnVRwRtmiHeqivyPxSnmdXKC9Xv4nhKbz30iNAAf7htXcCItxVk/I99JWw3Kg1nIiu nIOA== X-Forwarded-Encrypted: i=1; AJvYcCUlMJCvhbYrQORiTj81h2UvSbcGDs6ECfjJ9VVPUe7ymRQofwl47ba0g0aegt3HfvsQziyKr3P7vqzI+5BEQ+zpY18= X-Gm-Message-State: AOJu0YyzuWxQYhEcZ3zTNnpzTrdUDD2vJAOvKMrr/eAOsym8yGgcWVss IdLyT3MbmKc1Y39TfylQDGlZPmVne5wR1ipyJlnaeSMxWdP0wyvqz30crQXiZw== X-Google-Smtp-Source: AGHT+IFsGRjvigUxgTTtTqGgMnNIg8YFES6i9HDNADq5rjt43maW5TChLkUemeXXADRcsznTywdH0A== X-Received: by 2002:a0d:c782:0:b0:62d:a29:5384 with SMTP id 00721157ae682-62d0a2954a3mr52702187b3.43.1718097258846; Tue, 11 Jun 2024 02:14:18 -0700 (PDT) Received: from darker.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id 00721157ae682-62ccacade03sm19192037b3.27.2024.06.11.02.14.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 11 Jun 2024 02:14:18 -0700 (PDT) Date: Tue, 11 Jun 2024 02:13:59 -0700 (PDT) From: Hugh Dickins To: Yosry Ahmed cc: syzbot , akpm@linux-foundation.org, chengming.zhou@linux.dev, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, nphamcs@gmail.com, syzkaller-bugs@googlegroups.com, Hugh Dickins , Jan Kara , linux-ext4@vger.kernel.org Subject: Re: [syzbot] [mm?] KMSAN: uninit-value in zswap_store In-Reply-To: Message-ID: <02a21a55-8fe3-a9eb-f54b-051d75ae8335@google.com> References: <000000000000d0f165061a6754c3@google.com> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="-1463770367-1445972292-1718097257=:2984" X-Rspam-User: X-Rspamd-Queue-Id: 1BC2840016 X-Rspamd-Server: rspam01 X-Stat-Signature: z4whoh3yjaxs81ina3bb6f48xzsriwbx X-HE-Tag: 1718097260-835155 X-HE-Meta: U2FsdGVkX1/I31cMLDvN9QHk3HCxB3mtcJVP4Nes+wU9UENJ2tluK4dAFmEB9/PsZimchTZzoBTrGxqTIIsftwvQUtgZbNqiGFGqMzhhzUcS7BwVpR9jRnzprJg29Bd491UlDxfWC6hWWOIld9B9y0Ulc7fUmvMxwwAAQSBusACT8MQ6GBlwcaJ+xm5Yg8wq4D/usr7i8lvdlHKzObs5RlS9YSpCoZHiTz+m8+izX7be4NsZ+YCyV+zm6w1jpAUVBQummVjgbk1mGBxaccECGZXYvhjJIipevOQ2mIr1u6AV7/VqloGfElWqb7yHHi/nabt4/MtgONkDxTpnfwfpaYY9+Z8lxaU5H2mlaVxv9ad9cW53xr5zaL6fbvLcYKpuAmieQt2OuPpJPo6naE+SpyhH/TcUCUVWR1vpNgUka+gRojaiYd4ny+5K8JaWvTtpS79dr0D+sn072/qNcavMIyWKZx16nSjiCUMNMRLQI5mbxoW1BGUFuDRj2nnQQLcvLa9qLR+6e2AuSH9wf9f8nbM8jJ/+wqRAvU81SOPPBm17X0+D6qy3BnNxP6doRWhzl8uh45XcX3hK/6X1rHqT4zdEczGthi49vfgmnWRA6nY86WoCwbCTPGSnaIySUfeih6MxoD5ibC19Ffaw6yqvX4b//VXGhKBtjbdDsX1uhqI+/cdfwbr1uaSEkwNByDxjrghofbUDmzllRiMuqcBgOqwiLr48CZXd7GP/HRTjwbC5Ff4Kmso9bnZN71YQkNkmn75WKaU1BgqhB7aUWXliAvKKoGsxhqOyYj22fkTTC/Hiw0lZtbUfl3AxAxQyCOYXLik/zdGMIBmlCqrbF+VpgzAHBFw65SFZ2qz8yefbOLrRvHTeeOv68iwfuNVqTlgwHoR1cxBywm2kN91ohF8gTraMMOmCmIS8kz69SjH5WuGgUxHusBIOJXJjCRE1b7h4awB3eriku4FwUJcKdDa jcXuJi31 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 uhMEzP7A /16GkIoL6tj7JjCOIxHEbCDSmVNoenPgF+hZkppzNg+DeKi8lVGPaHJj+jSiL5kfWLt/Q9NOJODVxWsR/MVUliaIRiRG3HpskibUCzdgv9vBHCLa1YiB7UXR1ka3DOL65AywLNnyOdFvmI8RM1SD449cA726VDNUSljmK9Sw4TOCBJDXhl8kTw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000017, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---1463770367-1445972292-1718097257=:2984 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE On Mon, 10 Jun 2024, Yosry Ahmed wrote: > On Sat, Jun 8, 2024 at 2:09=E2=80=AFPM syzbot > wrote: > > > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: 614da38e2f7a Merge tag 'hid-for-linus-2024051401' of gi= t:/.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=3D113f3fd6980= 000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=3Df5d2cbf3363= 3f507 > > dashboard link: https://syzkaller.appspot.com/bug?extid=3D9c1fe13fcb515= 74b249b > > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for D= ebian) 2.40 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > Downloadable assets: > > disk image: https://storage.googleapis.com/syzbot-assets/89eafb874b71/d= isk-614da38e.raw.xz > > vmlinux: https://storage.googleapis.com/syzbot-assets/356000512ad9/vmli= nux-614da38e.xz > > kernel image: https://storage.googleapis.com/syzbot-assets/839c73939115= /bzImage-614da38e.xz > > > > IMPORTANT: if you fix the issue, please add the following tag to the co= mmit: > > Reported-by: syzbot+9c1fe13fcb51574b249b@syzkaller.appspotmail.com >=20 > This doesn't look like a zswap bug, and perhaps not a bug at all but I > am not sure. Zswap is reading the data in a folio to check if it is > filled with a repeated pattern, and it is encountering uninitialized > data. I am not sure if this is expected behavior or not. I agree, it doesn't look like a zswap bug: zswap is just following orders. >=20 > Could it just be that the size of the data written by syzbot is not > divisible by PAGE_SIZE, so part of the final page is left > uninitialized? Do we keep the unwritten parts of a shmem page > uninitialized by any chance? Shmem can keep uninitialized data pages around, but should be zeroing what's still uninitialized before it can reach the outside world - in this case being written to swap. I don't know of a shmem bug here. >=20 > Hugh, do you mind taking a quick look at whether this is a real bug? >=20 > If this is expected behavior, perhaps there is some annotation we can > use in zswap that it is fine to encounter uninitialized data when > reading the folio. I've not been faced with a KMSAN report before, so I might well be misunderstanding its language: but this looks like an ext4 "bug" to me. I think the story that the three KMSAN stacks are telling is this: syzbot has an ext4 filesystem on a loop device on a tmpfs file (I do exactly that too); ext4 is doing some ext4_xattr_inode_write() business, in the course of which it writes back a not-fully-initialized block to the loop device; shmem faithfully copies that data into its pagecache, then later when under memory pressure that page gets "written" out to zswap: where zswap_is_page_same_filled() takes an interest in the data, and KMSAN objects because some of it was not originally initialized. If that's a correct interpretation, then it's probably not a big deal: it's probably the uninitialized end of a buffer that's written out, not any part of the "disk" which ext4 would ever show to a user; but I do agree with KMSAN that ext4 would do better to clear that area, rather than accidentally storing someone else's super-secret info. Hugh >=20 > > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D > > BUG: KMSAN: uninit-value in zswap_is_page_same_filled mm/zswap.c:1481 [= inline] > > BUG: KMSAN: uninit-value in zswap_store+0x1008/0x2ca0 mm/zswap.c:1553 > > zswap_is_page_same_filled mm/zswap.c:1481 [inline] > > zswap_store+0x1008/0x2ca0 mm/zswap.c:1553 > > swap_writepage+0x126/0x4c0 mm/page_io.c:198 > > shmem_writepage+0x1826/0x1f70 mm/shmem.c:1518 > > pageout mm/vmscan.c:660 [inline] > > shrink_folio_list+0x4a55/0x7910 mm/vmscan.c:1323 > > evict_folios+0x9d7f/0xcc20 mm/vmscan.c:4537 > > try_to_shrink_lruvec+0x160e/0x1a50 mm/vmscan.c:4733 > > shrink_one+0x66f/0xd40 mm/vmscan.c:4772 > > shrink_many mm/vmscan.c:4835 [inline] > > lru_gen_shrink_node mm/vmscan.c:4935 [inline] > > shrink_node+0x4856/0x55f0 mm/vmscan.c:5894 > > kswapd_shrink_node mm/vmscan.c:6704 [inline] > > balance_pgdat mm/vmscan.c:6895 [inline] > > kswapd+0x1eba/0x4460 mm/vmscan.c:7164 > > kthread+0x3e2/0x540 kernel/kthread.c:389 > > ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > Uninit was stored to memory at: > > memcpy_from_iter lib/iov_iter.c:73 [inline] > > iterate_bvec include/linux/iov_iter.h:122 [inline] > > iterate_and_advance2 include/linux/iov_iter.h:249 [inline] > > iterate_and_advance include/linux/iov_iter.h:271 [inline] > > __copy_from_iter lib/iov_iter.c:249 [inline] > > copy_page_from_iter_atomic+0x12b7/0x2ae0 lib/iov_iter.c:481 > > generic_perform_write+0x4c1/0xc60 mm/filemap.c:3982 > > shmem_file_write_iter+0x2bd/0x2f0 mm/shmem.c:2920 > > do_iter_readv_writev+0x7e6/0x960 > > vfs_iter_write+0x459/0xd00 fs/read_write.c:895 > > lo_write_bvec drivers/block/loop.c:246 [inline] > > lo_write_simple drivers/block/loop.c:267 [inline] > > do_req_filebacked drivers/block/loop.c:491 [inline] > > loop_handle_cmd drivers/block/loop.c:1907 [inline] > > loop_process_work+0x1502/0x3440 drivers/block/loop.c:1942 > > loop_rootcg_workfn+0x2b/0x40 drivers/block/loop.c:1973 > > process_one_work kernel/workqueue.c:3267 [inline] > > process_scheduled_works+0xa81/0x1bd0 kernel/workqueue.c:3348 > > worker_thread+0xea5/0x1560 kernel/workqueue.c:3429 > > kthread+0x3e2/0x540 kernel/kthread.c:389 > > ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147 > > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 > > > > Uninit was created at: > > __alloc_pages+0x9d6/0xe70 mm/page_alloc.c:4598 > > alloc_pages_mpol+0x299/0x990 mm/mempolicy.c:2264 > > alloc_pages mm/mempolicy.c:2335 [inline] > > folio_alloc+0x1d0/0x230 mm/mempolicy.c:2342 > > filemap_alloc_folio+0xa6/0x440 mm/filemap.c:984 > > __filemap_get_folio+0xa10/0x14b0 mm/filemap.c:1926 > > grow_dev_folio fs/buffer.c:1042 [inline] > > grow_buffers fs/buffer.c:1108 [inline] > > __getblk_slow fs/buffer.c:1134 [inline] > > bdev_getblk+0x39b/0xc80 fs/buffer.c:1429 > > __getblk include/linux/buffer_head.h:355 [inline] > > sb_getblk include/linux/buffer_head.h:361 [inline] > > ext4_getblk+0x3da/0xe00 fs/ext4/inode.c:843 > > ext4_xattr_inode_write fs/ext4/xattr.c:1421 [inline] > > ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1596 [inline] > > ext4_xattr_set_entry+0x574d/0x6880 fs/ext4/xattr.c:1718 > > ext4_xattr_block_set+0xb94/0x4fb0 fs/ext4/xattr.c:2037 > > ext4_xattr_move_to_block fs/ext4/xattr.c:2654 [inline] > > ext4_xattr_make_inode_space fs/ext4/xattr.c:2729 [inline] > > ext4_expand_extra_isize_ea+0x20bd/0x3560 fs/ext4/xattr.c:2821 > > __ext4_expand_extra_isize+0x5dc/0x680 fs/ext4/inode.c:5789 > > ext4_try_to_expand_extra_isize fs/ext4/inode.c:5832 [inline] > > __ext4_mark_inode_dirty+0x70d/0xa10 fs/ext4/inode.c:5910 > > ext4_delete_inline_entry+0x650/0x7d0 fs/ext4/inline.c:1753 > > ext4_delete_entry+0x13f/0x7d0 fs/ext4/namei.c:2719 > > __ext4_unlink+0x9b8/0x11b0 fs/ext4/namei.c:3273 > > ext4_unlink+0x226/0x630 fs/ext4/namei.c:3321 > > vfs_unlink+0x676/0xa30 fs/namei.c:4343 > > do_unlinkat+0x823/0xe10 fs/namei.c:4407 > > __do_sys_unlinkat fs/namei.c:4450 [inline] > > __se_sys_unlinkat fs/namei.c:4443 [inline] > > __x64_sys_unlinkat+0x17c/0x230 fs/namei.c:4443 > > x64_sys_call+0x846/0x3b50 arch/x86/include/generated/asm/syscalls_64.h= :264 > > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > > do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 > > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > > > CPU: 1 PID: 88 Comm: kswapd1 Not tainted 6.9.0-syzkaller-02707-g614da38= e2f7a #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS= Google 04/02/2024 > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D > > > > > > --- > > This report is generated by a bot. It may contain errors. > > See https://goo.gl/tpsmEJ for more information about syzbot. > > syzbot engineers can be reached at syzkaller@googlegroups.com. > > > > syzbot will keep track of this issue. See: > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > > > If the report is already addressed, let syzbot know by replying with: > > #syz fix: exact-commit-title > > > > If you want to overwrite report's subsystems, reply with: > > #syz set subsystems: new-subsystem > > (See the list of subsystem names on the web dashboard) > > > > If the report is a duplicate of another one, reply with: > > #syz dup: exact-subject-of-another-report > > > > If you want to undo deduplication, reply with: > > #syz undup >=20 ---1463770367-1445972292-1718097257=:2984--