INFO: task kworker/u4:3:14245 blocked for more than 143 seconds. Not tainted 6.8.0-rc7-syzkaller-00142-g3aaa8ce7a335 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:22584 pid:14245 tgid:14245 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x177f/0x49a0 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0x149/0x260 kernel/sched/core.c:6817 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6874 rwsem_down_write_slowpath+0xeea/0x13b0 kernel/locking/rwsem.c:1178 __down_write_common+0x1ae/0x200 kernel/locking/rwsem.c:1306 f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 f2fs_write_inode+0x3f0/0x470 fs/f2fs/inode.c:794 write_inode fs/fs-writeback.c:1473 [inline] __writeback_single_inode+0x69f/0xfd0 fs/fs-writeback.c:1690 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1987 wb_writeback+0x461/0xc80 fs/fs-writeback.c:2094 wb_check_background_flush fs/fs-writeback.c:2164 [inline] wb_do_writeback fs/fs-writeback.c:2252 [inline] wb_workfn+0xc33/0xfb0 fs/fs-writeback.c:2279 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130be0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 1 lock held by udevd/4512: #0: ffff8880b953c918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 2 locks held by getty/4825: #0: ffff88802b3660a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by syz-executor.4/5092: #0: ffffffff8e136578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #0: ffffffff8e136578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a3/0x890 kernel/rcu/tree_exp.h:995 4 locks held by kworker/u4:3/14245: #0: ffff888017ed1d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888017ed1d38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000c267d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000c267d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff88802380e0e0 (&type->s_umount_key#97){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff88803096d2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff88803096d2a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 3 locks held by kworker/u5:0/15292: #0: ffff888031f3b138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888031f3b138 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc90013367d20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc90013367d20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff888038641060 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:305 8 locks held by syz-executor.0/26219: 1 lock held by syz-executor.0/27662: 6 locks held by syz-executor.2/27671: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc7-syzkaller-00142-g3aaa8ce7a335 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2ef/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:243 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 27692 Comm: syz-executor.2 Not tainted 6.8.0-rc7-syzkaller-00142-g3aaa8ce7a335 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 RIP: 0033:0x7f418162968d Code: 0f 84 8e 00 00 00 48 8b 4f 18 48 8d 72 01 48 89 77 28 0f b6 34 11 ba 08 00 00 00 39 d0 0f 4f c2 85 c0 74 cd 89 f1 41 0f bf 11 <4d> 8d 71 02 d1 fe 83 e1 01 44 09 e9 41 89 c9 41 29 d1 45 39 d1 7c RSP: 002b:00007f41824ab500 EFLAGS: 00000202 RAX: 0000000000000004 RBX: 0000000000000010 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f41824ab670 RBP: 0000000000000000 R08: 0000000000000003 R09: 00007f41824ab5f6 R10: 0000000000000000 R11: 00007f41824ab5d0 R12: 0000000000000006 R13: 0000000000000002 R14: 00007f41824ab5f6 R15: 00007f41824ab670 FS: 00007f41824ac6c0 GS: 0000000000000000