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 5A856C433EF for ; Fri, 10 Jun 2022 01:24:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240100AbiFJBY2 (ORCPT ); Thu, 9 Jun 2022 21:24:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231691AbiFJBY1 (ORCPT ); Thu, 9 Jun 2022 21:24:27 -0400 Received: from mail-il1-f197.google.com (mail-il1-f197.google.com [209.85.166.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D96A72DA81 for ; Thu, 9 Jun 2022 18:24:25 -0700 (PDT) Received: by mail-il1-f197.google.com with SMTP id x5-20020a923005000000b002d1a91c4d13so18751998ile.4 for ; Thu, 09 Jun 2022 18:24:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:date:in-reply-to:message-id:subject :from:to; bh=n0Ch7+DU9ChBm9opkEwvPaHDcGkdnzEb2XEWkE5Tbz0=; b=nopkFsa9kTwfqLGWKgCd+UU3tGSpN5Cwed+aJ9GDASghKZivIXWr0nDRVT4TPT9uuP 4GiNdyiJmv24lfRgWb1tiXBnJ9FVuLdzxR74nD4HA7yrYOH359iOS/DvzcaOxJHX6P9u p++RrKjbnfAjz0RMSnYgHMx54BeE27qhwtilJ+D/pJbig0w0UOf6PIomFmN394yeIDl9 ZU4GPv1tXC1idzpxnzHq+qyLSrunynUwgezLEZpBEsdkM45vpRS6UzCjaKnB3p+m99Xl 0TBpAsZTNot/O3I9+ZMAQTEOlsCqv4UJR8uBSiFAF3viX98SMTk9b+R9/7T1LW0AXoeB uG6w== X-Gm-Message-State: AOAM530iCXL6i/IZCe17kZQZdV+MLM+5PQ86cgB2vOfHlbIgtvzw0lfe /TCAU/nhP8SAMvQgl3T3NhOEZOnlulsJAbnyTMovB5h66kpZ X-Google-Smtp-Source: ABdhPJzjg59yvuNzBbkLIKpk4zMOxAOYYp7M22Dj8lcRIyMUNweOFwHFy1SP9AuENBe/T7CDUhVXJxniffYE8syJyYpyU1X5G7Bh MIME-Version: 1.0 X-Received: by 2002:a92:c242:0:b0:2d1:e04f:43c0 with SMTP id k2-20020a92c242000000b002d1e04f43c0mr23944404ilo.111.1654824265255; Thu, 09 Jun 2022 18:24:25 -0700 (PDT) Date: Thu, 09 Jun 2022 18:24:25 -0700 In-Reply-To: <0000000000003ce9d105e0db53c8@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000007f13ca05e10dccc0@google.com> Subject: Re: [syzbot] KASAN: use-after-free Read in copy_page_from_iter_atomic (2) From: syzbot To: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, willy@infradead.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org syzbot has found a reproducer for the following issue on: HEAD commit: ff539ac73ea5 Add linux-next specific files for 20220609 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1627d920080000 kernel config: https://syzkaller.appspot.com/x/.config?x=a5002042f00a8bce dashboard link: https://syzkaller.appspot.com/bug?extid=d2dd123304b4ae59f1bd compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10d6d7cff00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1113b2bff00000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d2dd123304b4ae59f1bd@syzkaller.appspotmail.com BTRFS error (device loop0): bad tree block start, want 30490624 have 0 ================================================================== BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0xef6/0x1b30 lib/iov_iter.c:969 Read of size 4096 at addr ffff888170801000 by task kworker/u4:0/8 CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.19.0-rc1-next-20220609-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: loop0 loop_rootcg_workfn Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 memcpy+0x20/0x60 mm/kasan/shadow.c:65 copy_page_from_iter_atomic+0xef6/0x1b30 lib/iov_iter.c:969 generic_perform_write+0x2b8/0x560 mm/filemap.c:3735 __generic_file_write_iter+0x2aa/0x4d0 mm/filemap.c:3855 generic_file_write_iter+0xd7/0x220 mm/filemap.c:3887 call_write_iter include/linux/fs.h:2057 [inline] do_iter_readv_writev+0x3d1/0x640 fs/read_write.c:742 do_iter_write+0x182/0x700 fs/read_write.c:868 vfs_iter_write+0x70/0xa0 fs/read_write.c:909 lo_write_bvec drivers/block/loop.c:249 [inline] lo_write_simple drivers/block/loop.c:271 [inline] do_req_filebacked drivers/block/loop.c:495 [inline] loop_handle_cmd drivers/block/loop.c:1859 [inline] loop_process_work+0xd83/0x2050 drivers/block/loop.c:1894 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 The buggy address belongs to the physical page: page:ffffea0005c20040 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x170801 flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000000000 ffffea0005c20048 ffffea0005c20048 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner info is not present (never set?) Memory state around the buggy address: ffff888170800f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888170800f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888170801000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888170801080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888170801100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================