From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oa2-f0.google.com (mail-oa2-f0.google.com [74.125.231.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB32E5237AD for ; Wed, 9 Sep 2026 11:08:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788952115; cv=none; b=Fo+kqp6+8+yU05O/mUOla6P588FEz2TjMeDJKS+fvemRuR08HipS3VTRifHC8ckaVkkVs62Je+N5NHmrpjEAy9mkWVisrZMLXzwuZ9GCSqGTrruWsG0rsNAXKv4/dtXip/LworeUEKfXEnYaB98bJfvLYQ8qJjIPXTf0xNEvNgY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788952115; c=relaxed/simple; bh=zLFT2midDUIE08jFtiZXoNTa28LZis4aapNizkR9Pl4=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=JYhc7zUMZF5pJ0E4lo5GFNpMFBOagptrszvgYw6vy48pRQv6HmNjppqqayimLUhKtP/ILnIwC/LIxSO6z63Ji7AFtWQONBcdI+6APF5WinW22zHbW58UUAr3mBExS+ngPD8LZKmW98QzWSbo/Jj90bT6ljRUplJcg44DOhlQ5D0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=74.125.231.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oa2-f0.google.com with SMTP id 586e51a60fabf-451e8472960so4569099fac.1 for ; Wed, 09 Sep 2026 04:08:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788952112; x=1789556912; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=poOtJKRFcKQRNN+xN9bSoCheSB1ECKcVLBbKDneilbo=; b=OxBVuMemyFH4HSxm9fJ6/IU8Hh1ZmCwXx5QN4M1SPC9aatPV8QfRkSk+5J7De2FFQK xNhM/2Qv4Her/TVAeTlrULOgJtsS29yhZyMOLBmLZUgn2Iu7L1bMuMfjKbAXmz75WVa4 GNFC0sYAgWNb+bg8klUqgmyMoYqHMNaGKVgce3tg1lDWGxfOEBGv0B/cQodGdta8L/S8 3PVxHpsk3PkZLU2n92zqW1nTmmuLndS521DxkQO1VQJTkR0o9NTbqBdABUJmrBt4R0D4 WBzAL3Boep4Ya5GParrqNvQzIplMjxfk+1yFwFHUuxqhc3CcN/qGRchCpsrxWlPq0pgO fI/Q== X-Forwarded-Encrypted: i=1; AKwUvBzz1+yQXlG8TX6wePWqFCGUFl71hqg9AXp7z3NAq0avyr8LtDCrjpkvAStnKh4MMPcSf6USs20LthtoUuA=@vger.kernel.org X-Gm-Message-State: AFuF++ldydcb2Ac5+4v+rEolrKPs0Mte1Pjkk1H69Eg9eIltcKXAqQIS rysmz6U9oSuLY8PHg6sN+9UQLQS+hnV2W4QanDt46vk5+w8MsFx3SixaVPEd/d7c9JUROLIz0zw jEcX+zKTs2yqKKHe92tJ/zZw4PYMrb9iwXYCBF4IDkjeqDuTWe9RJ5fKP+tA= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:f08:b0:6bd:ec40:e809 with SMTP id 006d021491bc7-6bee4da46bdmr181333eaf.13.1788952112746; Wed, 09 Sep 2026 04:08:32 -0700 (PDT) Date: Wed, 09 Sep 2026 04:08:32 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aa13e30.f614420e.2bf292.0015.GAE@google.com> Subject: [syzbot] [exfat?] WARNING in fat_write_inode From: syzbot To: hirofumi@mail.parknet.co.jp, linkinjeon@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, sj1557.seo@samsung.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 654ae5d73c05 Merge tag 'drm-fixes-2026-09-05' of https://g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=146d68f9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=e909ffe6b35dddb7 dashboard link: https://syzkaller.appspot.com/bug?extid=4cb66d4011e51657d6b4 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-654ae5d7.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b52a78a429eb/vmlinux-654ae5d7.xz kernel image: https://storage.googleapis.com/syzbot-assets/ee752e9e76b3/bzImage-654ae5d7.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+4cb66d4011e51657d6b4@syzkaller.appspotmail.com ------------[ cut here ]------------ !buffer_uptodate(bh) WARNING: fs/buffer.c:991 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:991, CPU#0: syz.0.0/5320 Modules linked in: CPU: 0 UID: 0 PID: 5320 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:mark_buffer_dirty+0x299/0x410 fs/buffer.c:991 Code: 4c 89 f7 e8 d9 01 d8 ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 74 52 fb ff e8 bf 8b 66 ff eb 8c e8 b8 8b 66 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 aa 8b 66 ff 90 0f 0b 90 e9 cf fd ff ff RSP: 0018:ffffc9000e3cf850 EFLAGS: 00010293 RAX: ffffffff82614078 RBX: ffff888043def620 RCX: ffff8880003fcb00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 RBP: ffffc9000e3cf901 R08: ffff888043def627 R09: 1ffff110087bdec4 R10: dffffc0000000000 R11: ffffed10087bdec5 R12: 1ffff92001c79f20 R13: ffff888043def620 R14: ffff888041c13410 R15: dffffc0000000000 FS: 00005555923af540(0000) GS:ffff88808c2cd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563f7528d660 CR3: 000000004429a000 CR4: 0000000000352ef0 Call Trace: __fat_write_inode fs/fat/inode.c:946 [inline] fat_write_inode+0x939/0xca0 fs/fat/inode.c:963 write_inode fs/fs-writeback.c:1608 [inline] __writeback_single_inode+0x69d/0x1220 fs/fs-writeback.c:1851 writeback_single_inode+0x544/0xf70 fs/fs-writeback.c:1926 sync_inode_metadata+0x122/0x1d0 fs/fs-writeback.c:3100 writeback_inode fs/fat/inode.c:1916 [inline] fat_flush_inodes+0x9b/0x1d0 fs/fat/inode.c:1936 fat_file_release+0xe0/0x1a0 fs/fat/file.c:180 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f597199e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff8b9d4328 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f5971c27da0 RCX: 00007f597199e159 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f5971c27da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007f5971c27cb0 R11: 0000000000000246 R12: 00000000000179c9 R13: 00007f5971c2645c R14: 0000000000017964 R15: 00007fff8b9d4430 --- 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