INFO: task segctord:6775 blocked for more than 149 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:segctord state:D stack:27760 pid: 6775 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 rwsem_down_write_slowpath+0xc87/0x1260 kernel/locking/rwsem.c:1165 nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline] nilfs_segctor_thread+0x518/0x1180 fs/nilfs2/segment.c:2647 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 5 locks held by kworker/1:1/23: #0: ffff8881411c0938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90000ddfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888023d55220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #2: ffff888023d55220 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x55e0 drivers/usb/core/hub.c:5827 #3: ffff888078a71220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #3: ffff888078a71220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954 #4: ffff88807650a1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #4: ffff88807650a1a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954 1 lock held by khungtaskd/27: #0: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:1/144: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900016afd00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/u4:4/1331: #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90005537d00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by udevd/3561: #0: ffff88802037e118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 1 lock held by dhcpcd/3853: #0: ffffffff8d43dbc8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x700 net/netlink/af_netlink.c:2352 2 locks held by getty/3947: #0: ffff88802bfad098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 5 locks held by kworker/1:6/4235: #0: ffff8881411c0938 ( (wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900031afd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff888023d45220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #2: ffff888023d45220 (&dev->mutex){....}-{3:3}, at: hub_event+0x19f/0x55e0 drivers/usb/core/hub.c:5827 #3: ffff88804bef4220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #3: ffff88804bef4220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954 #4: ffff88804ab221a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #4: ffff88804ab221a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x480 drivers/base/dd.c:954 5 locks held by kworker/u4:6/4273: #0: ffff888016dcd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900032bfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8d431cd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x148/0xba0 net/core/net_namespace.c:589 #3: ffffffff8d43dbc8 ( rtnl_mutex){+.+.}-{3:3}, at: vti6_exit_batch_net+0xbb/0x420 net/ipv6/ip6_vti.c:1185 #4: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #4: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by kworker/1:12/4352: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900041cfd00 ( (work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 2 locks held by kworker/1:16/5269: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000398fd00 ( (work_completion)(&rew.rew_work) ){+.+.}-{0:0} , at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 3 locks held by kworker/1:18/5271: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900039dfd00 ( (work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c323da8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 4 locks held by udevd/5647: #0: ffff888062618c30 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff88805f18d088 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112 #2: ffff888060f0b578 ( kn->active #32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113 #3: ffff88804bef4220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline] #3: ffff88804bef4220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408 6 locks held by syz.6.574/6776: 1 lock held by segctord/6775: #0: ffff88806024c2a0 (&nilfs->ns_segctor_sem){++++}-{3:3}, at: nilfs_transaction_lock+0x252/0x4c0 fs/nilfs2/segment.c:357 2 locks held by syz-executor/8547: #0: ffff88801fb1fd18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888147c43468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 1 lock held by udevd/8854: #0: ffff88802037e118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 2 locks held by syz.8.1096/9421: #0: ffff88802037e118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff88802031d468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6776 Comm: syz.6.574 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:rb_set_parent_color include/linux/rbtree_augmented.h:165 [inline] RIP: 0010:____rb_erase_color lib/rbtree.c:345 [inline] RIP: 0010:rb_erase+0xb27/0xe60 lib/rbtree.c:445 Code: 49 89 45 10 4c 89 eb 48 83 cb 01 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 59 d1 b7 fd <49> 89 1c 24 48 85 ed 4c 8b 34 24 74 2d 48 89 e8 48 c1 e8 03 48 b9 RSP: 0018:ffffc90000dd0ca8 EFLAGS: 00000046 RAX: 1ffff920005c9f5c RBX: ffff8880b912ac09 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: ffff8880b912a310 RDI: ffffc90002edfd88 RBP: ffffc9000347fd80 R08: ffffffff8d89f82f R09: 1ffffffff1b13f05 R10: dffffc0000000000 R11: fffffbfff1b13f06 R12: ffffc90002e4fae0 R13: ffff8880b912ac08 R14: 1ffff11017225581 R15: 1ffff920005cdfb1 FS: 00007f7f5b8056c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0210622000 CR3: 000000007a628000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rb_erase_cached include/linux/rbtree.h:126 [inline] timerqueue_del+0xaa/0x100 lib/timerqueue.c:57 __remove_hrtimer kernel/time/hrtimer.c:1102 [inline] __run_hrtimer kernel/time/hrtimer.c:1665 [inline] __hrtimer_run_queues+0x366/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:console_trylock_spinning+0x301/0x370 kernel/printk/printk.c:1909 Code: 85 db 74 89 e8 10 ea 18 00 fb 31 c0 eb 48 e8 06 ea 18 00 e8 a1 8d 5c 08 48 85 db 74 d1 e8 f7 e9 18 00 fb 48 c7 c7 60 3e 31 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 68 1a 4c 60 RSP: 0018:ffffc9000322f4e0 EFLAGS: 00000246 RAX: ffffffff81604c19 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc90005941000 RSI: 000000000007ffff RDI: ffffffff8c313e60 RBP: ffffc9000322f5b0 R08: ffffffff901d61cf R09: 1ffffffff203ac39 R10: dffffc0000000000 R11: fffffbfff203ac3a R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff92000645e9c vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273 _printk+0xda/0x130 kernel/printk/printk.c:2299 __nilfs_msg+0x2d8/0x3b0 fs/nilfs2/super.c:78 nilfs_clean_segments+0x5b9/0xa30 fs/nilfs2/segment.c:2535 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:940 [inline] nilfs_ioctl+0x2052/0x2190 fs/nilfs2/ioctl.c:1304 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f7f5d5cce59 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:00007f7f5b805028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7f5d846090 RCX: 00007f7f5d5cce59 RDX: 0000200000000640 RSI: 0000000040786e88 RDI: 0000000000000005 RBP: 00007f7f5d662d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7f5d846128 R14: 00007f7f5d846090 R15: 00007ffc5f33a088