INFO: task segctord:25242 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:segctord state:D stack:28680 pid:25242 tgid:25242 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 __schedule_loop kernel/sched/core.c:7049 [inline] schedule+0x164/0x360 kernel/sched/core.c:7064 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7121 rwsem_down_write_slowpath+0x883/0x1080 kernel/locking/rwsem.c:1215 __down_write_common kernel/locking/rwsem.c:1347 [inline] __down_write kernel/locking/rwsem.c:1356 [inline] down_write+0x1bc/0x200 kernel/locking/rwsem.c:1626 nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline] nilfs_segctor_thread+0x6b5/0xdc0 fs/nilfs2/segment.c:2684 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 INFO: task syz.4.4075:26728 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4075 state:D stack:25432 pid:26728 tgid:26727 ppid:21952 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5354 [inline] __schedule+0x165c/0x5520 kernel/sched/core.c:6966 __schedule_loop kernel/sched/core.c:7049 [inline] schedule+0x164/0x360 kernel/sched/core.c:7064 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227 sync_inodes_sb+0x225/0xbf0 fs/fs-writeback.c:2942 __iterate_supers+0x13d/0x250 fs/super.c:927 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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 RIP: 0033:0x7f1b1759c799 RSP: 002b:00007f1b157f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1b17815fa0 RCX: 00007f1b1759c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1b17815fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1b17816038 R14: 00007f1b17815fa0 R15: 00007ffe98065eb8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75d0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75d0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75d0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/69: 2 locks held by getty/5596: #0: ffff8880376e70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:12/7757: #0: ffff888020688940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3253 [inline] #0: ffff888020688940 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3361 #1: ffffc9001b737c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3254 [inline] #1: ffffc9001b737c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3361 4 locks held by syz.1.3849/25224: 1 lock held by segctord/25242: #0: ffff888022ab8288 (&nilfs->ns_segctor_sem){++++}-{4:4}, at: nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 3 locks held by syz-executor/26015: #0: ffff88807e5140d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807e5140d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807e5140d8 (&type->s_umount_key#52){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffff8880803e4b68 (&fs_info->ordered_operations_mutex){+.+.}-{4:4}, at: btrfs_wait_ordered_roots+0xe7/0x6f0 fs/btrfs/ordered-data.c:822 #2: ffff88804649a788 (&root->ordered_extent_mutex){+.+.}-{4:4}, at: btrfs_wait_ordered_extents+0x234/0xce0 fs/btrfs/ordered-data.c:766 2 locks held by kworker/u8:5/26553: #0: ffff888077db9940 ((wq_completion)btrfs-flush_delalloc){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3253 [inline] #0: ffff888077db9940 ((wq_completion)btrfs-flush_delalloc){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3361 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by syz.4.4075/26728: #0: ffff8880737040d8 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880737040d8 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff888026b40810 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline] #1: ffff888026b40810 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xbf0 fs/fs-writeback.c:2940 1 lock held by syz.6.4390/28744: #0: ffffffff8e7632b8 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 1 lock held by syz.6.4390/28745: #0: ffff8880362f3aa0 (sk_lock-AF_QIPCRTR){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff8880362f3aa0 (sk_lock-AF_QIPCRTR){+.+.}-{0:0}, at: qrtr_recvmsg+0xd0/0x970 net/qrtr/af_qrtr.c:1035 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 19346 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:lock_acquire+0xe7/0x350 kernel/locking/lockdep.c:5868 Code: 9c 41 5f fa 48 c7 c7 58 1b f6 8d e8 c3 5a 10 0a 65 ff 05 0c 30 7c 11 45 31 c9 4c 89 7c 24 08 41 f7 c7 00 02 00 00 41 0f 94 c1 <4c> 89 ef 89 de 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 RSP: 0018:ffffc900000076b8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000102 RDX: 0000000000000000 RSI: ffffffff8df61b58 RDI: ffffffff8c288380 RBP: ffffffff81771696 R08: 0000000000000000 R09: 0000000000000001 R10: ffffc90000007878 R11: ffffffff81b15b50 R12: 0000000000000002 R13: ffffffff8e75d0e0 R14: 0000000000000000 R15: 0000000000000046 FS: 0000555595445500(0000) GS:ffff88812543f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e1d9a75f78 CR3: 00000000844ee000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2202 __queue_work+0xccf/0xfc0 kernel/workqueue.c:2357 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1794 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x67e/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 b2 16 21 00 fb eb 44 e8 aa 16 21 00 e8 75 58 0d 0a 4d 85 f6 74 94 e8 9b 16 21 00 fb 48 c7 c7 00 f5 74 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18 RSP: 0018:ffffc900041cf9a0 EFLAGS: 00000293 RAX: ffffffff81a50be5 RBX: ffffffff81a50a5f RCX: ffff88802dc71e80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e74f500 RBP: ffffc900041cfa50 R08: ffffffff90128af7 R09: 1ffffffff202515e R10: dffffc0000000000 R11: fffffbfff202515f R12: 0000000000000000 R13: 000000000000002d R14: 0000000000000200 R15: 1ffff92000839f38 _printk+0xdd/0x130 kernel/printk/printk.c:2504 lmLogSync+0x7b8/0xa50 fs/jfs/jfs_logmgr.c:983 jfs_syncpt+0x7b/0x90 fs/jfs/jfs_logmgr.c:1039 jfs_sync_fs+0x87/0xa0 fs/jfs/super.c:650 sync_filesystem+0x1cf/0x230 fs/sync.c:66 generic_shutdown_super+0x77/0x2d0 fs/super.c:625 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 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:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb79259d9d7 Code: a2 c7 05 1c fd 24 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffcff845448 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fb792632050 RCX: 00007fb79259d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcff845500 RBP: 00007ffcff845500 R08: 00007ffcff846500 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcff846590 R13: 00007fb792632050 R14: 00000000001a18da R15: 00007ffcff8465d0