INFO: task kworker/u8:2:35 blocked for more than 143 seconds. Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:2 state:D stack:20696 pid:35 tgid:35 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_unbound netfs_write_collection_worker Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 bit_wait+0x12/0xd0 kernel/sched/wait_bit.c:237 __wait_on_bit+0xb0/0x2f0 kernel/sched/wait_bit.c:49 out_of_line_wait_on_bit+0x1d5/0x260 kernel/sched/wait_bit.c:64 wait_on_bit include/linux/wait_bit.h:77 [inline] netfs_retry_writes+0x16e/0x19b0 fs/netfs/write_retry.c:215 netfs_collect_write_results fs/netfs/write_collect.c:352 [inline] netfs_write_collection_worker+0x2f90/0x3bb0 fs/netfs/write_collect.c:374 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 3 locks held by kworker/0:0/8: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3317 #1: ffffc900000d7c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900000d7c60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3317 #2: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #2: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 1 lock held by khungtaskd/30: #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/u8:2/35: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3317 #1: ffffc90000ab7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90000ab7c60 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3317 2 locks held by getty/5590: #0: ffff888031acb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 3 locks held by syz.1.1510/11227: #0: ffff888012352420 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3035 [inline] #0: ffff888012352420 (sb_writers#17){.+.+}-{0:0}, at: vfs_writev+0x2d6/0xbc0 fs/read_write.c:1048 #1: ffff88805a14ae58 (&sb->s_type->i_mutex_key#28){++++}-{4:4}, at: netfs_start_io_write+0xd7/0x100 fs/netfs/locking.c:112 #2: ffff88805a14b210 (&ctx->wb_lock){+.+.}-{4:4}, at: netfs_begin_writethrough+0x68/0x140 fs/netfs/write_issue.c:623 3 locks held by syz.2.1904/12586: #0: ffffffff8feb5890 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:512 #1: ffffffff8fec2008 (rtnl_mutex){+.+.}-{4:4}, at: setup_net+0x602/0x9e0 net/core/net_namespace.c:384 #2: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #2: ffffffff8eb3e438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996 2 locks held by syz.0.1914/12622: #0: ffffffff8fec2008 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fec2008 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3b/0x1b0 drivers/net/tun.c:3517 #1: ffff8880b863e7d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606 3 locks held by syz.6.1915/12624: #0: ffff88805cc0cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline] #0: ffff88805cc0cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677 #1: ffff88805cc0c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60d/0x1260 net/bluetooth/hci_sync.c:5185 #2: ffff888059b56b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1760 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111