From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (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 1EAE123909C for ; Fri, 24 Apr 2026 02:35:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776998137; cv=none; b=qqA88rMnQh9kLJlKG742Me1eje4s+FcLTKAnm9zS+hWLT7J3atg5cfuYGHIaaAkQLNuN9dfwHR6Twt1KUrcgJ1vLj1f6M7+ED0FZrPr7tkl44HXtytEZTE4HNfqqKDrONyf6TC01PTdH0n+Bb8xMfaXiJ5AR9OnqMQUD0MW+7O0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776998137; c=relaxed/simple; bh=2EZvwEGcrt1tiwRLtcHMO0tM94itIV7GvCue78p0q08=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=k4RhMjb0sZdnGDQkTplxxH5xqBGDqVZtYGa1dEgu5q0EVOcYvGSguLHNY63lc4Lq5UYWX6/6PyzNfN9C7OWKkNbD4F14BoS2N8ytY6+tlCpyHYccn4yUonsY3OAJSeMBS6eMYzzGb3BHWo4FsUMOeiZZFwtld5dU2cYH+qciSpE= 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=209.85.210.77 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-ot1-f77.google.com with SMTP id 46e09a7af769-7dcd603855aso8685426a34.0 for ; Thu, 23 Apr 2026 19:35:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776998135; x=1777602935; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=/s6duOhe5iGwsgMoXyGArdKN1ztF9KS9kBveVk4qrQE=; b=BDqPPrzd25XEG+ob9Uy2D0v9zCF0Zo8LNhJLD/svuKAiZ2D8hnMOh5VGhV9kdtkYur kKg3WsD76DK1oKYEZld5onDZmRTqdTIqPeN3ABuHWsGF7bSG2JCiB9Yb0OELABvFgvQN z3vb4ufhS8/6pqXyLi4lEGm7AJhismWP8HTar2WQIxSgM8Sj5BQnYJTSoXQDGNe2GFy8 gvEYaEKUiYWuaxSlflJCndKMQmrs8TCZ8fmvdKlKMX6MxNIIZmulvsSw7QwkOLVMzpvU aTTFXaWNIKEQ//xdRmMwovyKnW+l9KMRs9+ZLBOtobbY8/2hKgzn/Rn47/ASBv2EW8iX E6hA== X-Forwarded-Encrypted: i=1; AFNElJ+Tr9JAKYsl6/Kl5xjwpNpCXTsCB82dMkSgv3C+mqOch3pdJRpjMEoQkRZSDWRSCCLpi8pTB+5o7KJZRm0=@vger.kernel.org X-Gm-Message-State: AOJu0YzP97NFn4/JH8LgdSZHBa0/TX6eHkv6W5lS5IHJESClq2DtdFLD LmQ4yFRJAahEcBhaUqNpFAcsip16MIc2z7RsFRy1xlrIxqHI2n6PW2n+/CEZNu2js+5mm9FKDu5 Ym1173Uma991qlyHXIQb69H02syOxvn29dp2z5kg3RCX1y04h9kR5zECKuOY= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:6186:b0:694:96b4:feb9 with SMTP id 006d021491bc7-69496b4ffe9mr5747159eaf.33.1776998135150; Thu, 23 Apr 2026 19:35:35 -0700 (PDT) Date: Thu, 23 Apr 2026 19:35:35 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69ead6f7.a00a0220.9259.002f.GAE@google.com> Subject: [syzbot] [btrfs?] possible deadlock in btrfs_finish_one_ordered (3) From: syzbot To: clm@fb.com, dsterba@suse.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: c1f49dea2b8f Merge tag 'mm-hotfixes-stable-2026-04-19-00-1.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12a7d4ce580000 kernel config: https://syzkaller.appspot.com/x/.config?x=2b4ac2aaea441e9b dashboard link: https://syzkaller.appspot.com/bug?extid=639b46ea64e2a7c2b93d compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/305242213735/disk-c1f49dea.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/1da8423852f9/vmlinux-c1f49dea.xz kernel image: https://storage.googleapis.com/syzbot-assets/d8bb8e7b4ae2/bzImage-c1f49dea.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+639b46ea64e2a7c2b93d@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ kworker/u8:12/27491 is trying to acquire lock: ffff888077978600 (sb_internal#2){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x88e/0x2680 fs/btrfs/inode.c:3254 but task is already holding lock: ffff88803966a758 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x39c/0x2680 fs/btrfs/inode.c:3216 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (btrfs_ordered_extent){++++}-{0:0}: btrfs_start_ordered_extent_nowriteback+0x390/0x700 fs/btrfs/ordered-data.c:890 btrfs_start_ordered_extent fs/btrfs/ordered-data.h:203 [inline] btrfs_wait_ordered_range+0x154/0x260 fs/btrfs/ordered-data.c:942 btrfs_sync_file+0x78a/0x1200 fs/btrfs/file.c:1662 generic_write_sync include/linux/fs.h:2654 [inline] btrfs_do_write_iter+0x6a3/0x840 fs/btrfs/file.c:1468 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61d/0xb90 fs/read_write.c:688 ksys_write+0x150/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #7 (&ei->i_mmap_lock){++++}-{4:4}: down_read+0x47/0x2e0 kernel/locking/rwsem.c:1568 btrfs_page_mkwrite+0x636/0x1a60 fs/btrfs/file.c:1918 do_page_mkwrite+0x14d/0x310 mm/memory.c:3668 wp_page_shared mm/memory.c:4069 [inline] do_wp_page+0x19ba/0x4cc0 mm/memory.c:4288 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x151d/0x3170 mm/memory.c:6718 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 -> #6 (sb_pagefaults#3){.+.+}-{0:0}: percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_pagefault include/linux/fs/super.h:159 [inline] btrfs_page_mkwrite+0x351/0x1a60 fs/btrfs/file.c:1873 do_page_mkwrite+0x14d/0x310 mm/memory.c:3668 wp_page_shared mm/memory.c:4069 [inline] do_wp_page+0x19ba/0x4cc0 mm/memory.c:4288 handle_pte_fault mm/memory.c:6427 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x151d/0x3170 mm/memory.c:6718 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] _inline_copy_to_user include/linux/uaccess.h:206 [inline] _copy_to_user+0x85/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:236 [inline] do_pipe2+0xd4/0x190 fs/pipe.c:1040 __do_sys_pipe fs/pipe.c:1061 [inline] __se_sys_pipe fs/pipe.c:1059 [inline] __x64_sys_pipe+0x3a/0x50 fs/pipe.c:1059 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&mm->mmap_lock){++++}-{4:4}: down_write_killable+0xa6/0x240 kernel/locking/rwsem.c:1637 mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] upgrade_mmap_lock_carefully+0xba/0x1b0 mm/mmap_lock.c:474 lock_mm_and_find_vma+0x12b/0x340 mm/mmap_lock.c:527 do_user_addr_fault+0x330/0x1340 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 filldir64+0x2b2/0x640 fs/readdir.c:368 dir_emit include/linux/fs.h:3578 [inline] offset_dir_emit fs/libfs.c:499 [inline] offset_iterate_dir fs/libfs.c:515 [inline] offset_readdir+0x3fc/0x530 fs/libfs.c:564 iterate_dir+0x399/0x570 fs/readdir.c:110 __do_sys_getdents64 fs/readdir.c:399 [inline] __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&type->i_mutex_dir_key#5){++++}-{4:4}: down_read+0x47/0x2e0 kernel/locking/rwsem.c:1568 inode_lock_shared include/linux/fs.h:1044 [inline] lookup_slow+0x46/0x70 fs/namei.c:1931 walk_component fs/namei.c:2278 [inline] lookup_last fs/namei.c:2785 [inline] path_lookupat+0x3f5/0x8c0 fs/namei.c:2809 filename_lookup+0x256/0x5d0 fs/namei.c:2838 kern_path+0x3d/0x150 fs/namei.c:3044 is_same_device fs/btrfs/volumes.c:764 [inline] device_list_add+0xfd1/0x2280 fs/btrfs/volumes.c:898 btrfs_scan_one_device+0x3ef/0x680 fs/btrfs/volumes.c:1499 btrfs_get_tree_super fs/btrfs/super.c:1858 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline] btrfs_get_tree+0x4ab/0x1910 fs/btrfs/super.c:2121 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&fs_devs->device_list_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:632 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:806 insert_dev_extents fs/btrfs/block-group.c:2876 [inline] btrfs_create_pending_block_groups+0x77b/0x1b40 fs/btrfs/block-group.c:2927 __btrfs_end_transaction+0x140/0x650 fs/btrfs/transaction.c:1091 flush_space+0x406/0xe20 fs/btrfs/space-info.c:912 do_async_reclaim_data_space+0x145/0x520 fs/btrfs/space-info.c:1448 btrfs_async_reclaim_data_space+0x41/0x90 fs/btrfs/space-info.c:1512 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x192/0xe40 fs/btrfs/transaction.c:324 start_transaction+0xbef/0x1820 fs/btrfs/transaction.c:719 btrfs_dirty_inode+0x9f/0x190 fs/btrfs/inode.c:6441 touch_atime+0x2f8/0x6b0 fs/inode.c:2265 file_accessed include/linux/fs.h:2264 [inline] filemap_read+0x1053/0x1230 mm/filemap.c:2878 __kernel_read+0x504/0x9b0 fs/read_write.c:532 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline] ima_calc_file_hash+0x446/0x860 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x51d/0x9c0 security/integrity/ima/ima_api.c:300 process_measurement+0x12cd/0x1c80 security/integrity/ima/ima_main.c:425 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685 security_file_post_open+0xb3/0x260 security/security.c:2755 do_open fs/namei.c:4701 [inline] path_openat+0x2e4d/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (btrfs_trans_num_writers){++++}-{0:0}: join_transaction+0x171/0xe40 fs/btrfs/transaction.c:323 start_transaction+0xbef/0x1820 fs/btrfs/transaction.c:719 btrfs_dirty_inode+0x9f/0x190 fs/btrfs/inode.c:6441 touch_atime+0x2f8/0x6b0 fs/inode.c:2265 file_accessed include/linux/fs.h:2264 [inline] filemap_read+0x1053/0x1230 mm/filemap.c:2878 __kernel_read+0x504/0x9b0 fs/read_write.c:532 integrity_kernel_read+0x89/0xd0 security/integrity/iint.c:28 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:222 [inline] ima_calc_file_hash+0x446/0x860 security/integrity/ima/ima_crypto.c:280 ima_collect_measurement+0x51d/0x9c0 security/integrity/ima/ima_api.c:300 process_measurement+0x12cd/0x1c80 security/integrity/ima/ima_main.c:425 ima_file_check+0xe1/0x130 security/integrity/ima/ima_main.c:685 security_file_post_open+0xb3/0x260 security/security.c:2755 do_open fs/namei.c:4701 [inline] path_openat+0x2e4d/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (sb_internal#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] start_transaction+0xaa9/0x1820 fs/btrfs/transaction.c:713 btrfs_finish_one_ordered+0x88e/0x2680 fs/btrfs/inode.c:3254 btrfs_work_helper+0x37b/0xc20 fs/btrfs/async-thread.c:312 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 other info that might help us debug this: Chain exists of: sb_internal#2 --> &ei->i_mmap_lock --> btrfs_ordered_extent Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(btrfs_ordered_extent); lock(&ei->i_mmap_lock); lock(btrfs_ordered_extent); rlock(sb_internal#2); *** DEADLOCK *** 3 locks held by kworker/u8:12/27491: #0: ffff88807c47f940 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88807c47f940 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006627c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006627c40 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff88803966a758 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x39c/0x2680 fs/btrfs/inode.c:3216 stack backtrace: CPU: 1 UID: 0 PID: 27491 Comm: kworker/u8:12 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: btrfs-endio-write btrfs_work_helper Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs/super.h:19 [inline] sb_start_intwrite include/linux/fs/super.h:177 [inline] start_transaction+0xaa9/0x1820 fs/btrfs/transaction.c:713 btrfs_finish_one_ordered+0x88e/0x2680 fs/btrfs/inode.c:3254 btrfs_work_helper+0x37b/0xc20 fs/btrfs/async-thread.c:312 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 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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