INFO: task kworker/u4:3:24194 blocked for more than 143 seconds. Not tainted 6.8.0-rc6-syzkaller-00037-g805d849d7c3c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:3 state:D stack:20112 pid:24194 tgid:24194 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) 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 2 locks held by getty/4816: #0: ffff88802aefb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 1 lock held by syz-executor.4/20459: #0: ffff8880230ac0e0 (&type->s_umount_key#56){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880230ac0e0 (&type->s_umount_key#56){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880230ac0e0 (&type->s_umount_key#56){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:504 4 locks held by kworker/u4:3/24194: #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #0: ffff888018acdd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #1: ffffc9000348fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2608 [inline] #1: ffffc9000348fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2706 #2: ffff88807ae020e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:561 #3: ffff8880754d12a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2138 [inline] #3: ffff8880754d12a8 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x500/0x730 fs/f2fs/segment.c:437 3 locks held by kworker/u4:1/1872: 6 locks held by syz-executor.2/8174: 1 lock held by syz-executor.0/10341: #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 1 lock held by syz-executor.3/10343: #0: ffff88802ddf20e0 (&type->s_umount_key#55/1){+.+.}-{3:3}, at: alloc_super+0x221/0x9d0 fs/super.c:343 2 locks held by syz-executor.2/10352: 1 lock held by syz-executor.1/10374: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc6-syzkaller-00037-g805d849d7c3c #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: kworker/u4:5 Not tainted 6.8.0-rc6-syzkaller-00037-g805d849d7c3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline] RIP: 0010:do_raw_spin_unlock+0x45/0x8b0 kernel/locking/spinlock_debug.c:141 Code: 00 fc ff df 48 8d 57 04 48 89 d0 48 c1 e8 03 48 89 44 24 10 0f b6 04 18 84 c0 48 89 14 24 0f 85 31 04 00 00 81 3a ad 4e ad de <0f> 85 04 01 00 00 4c 89 ff be 04 00 00 00 e8 e8 c2 7f 00 4c 89 f8 RSP: 0018:ffffc90004a37b90 EFLAGS: 00000046 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffc90004a37b03 RDX: ffff888014ca0004 RSI: ffffffff8baac7e0 RDI: ffff888014ca0000 RBP: ffffc90004a37dc8 R08: ffffffff8f843cef R09: 1ffffffff1f0879d R10: dffffc0000000000 R11: fffffbfff1f0879e R12: 1ffff110068ff0cc R13: dffffc0000000000 R14: ffff8880347f8660 R15: ffff888014ca0000 FS: 0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f12345a2000 CR3: 0000000029d20000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irq+0x1e/0x50 kernel/locking/spinlock.c:202 process_one_work kernel/workqueue.c:2606 [inline] process_scheduled_works+0x7f4/0x1420 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