INFO: task kworker/u8:4:67 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:21576 pid:67 tgid:67 ppid:2 task_flags:0x4248060 flags:0x00080000 Workqueue: xfs-cil/loop5 xlog_cil_push_work Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:289 [inline] __down_common+0x3d0/0x850 kernel/locking/semaphore.c:314 down+0x80/0xd0 kernel/locking/semaphore.c:100 xfs_buf_lock+0x14d/0x4c0 fs/xfs/xfs_buf.c:903 xfs_buf_item_unpin+0x1c4/0x700 fs/xfs/xfs_buf_item.c:551 xlog_cil_ail_insert fs/xfs/xfs_log_cil.c:-1 [inline] xlog_cil_committed+0x9dd/0x1140 fs/xfs/xfs_log_cil.c:995 xlog_cil_push_work+0x256b/0x2b10 fs/xfs/xfs_log_cil.c:1607 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 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.5.6027:25144 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.6027 state:D stack:26824 pid:25144 tgid:25102 ppid:23115 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0x164/0x360 kernel/sched/core.c:7282 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 __flush_workqueue+0x6f6/0x14f0 kernel/workqueue.c:4110 xlog_cil_push_now fs/xfs/xfs_log_cil.c:1725 [inline] xlog_cil_force_seq+0x228/0x8c0 fs/xfs/xfs_log_cil.c:1927 xfs_log_force_seq+0x196/0x440 fs/xfs/xfs_log.c:2984 __xfs_trans_commit+0x7e2/0xbf0 fs/xfs/xfs_trans.c:877 xfs_trans_commit+0x13e/0x1c0 fs/xfs/xfs_trans.c:926 xfs_sync_sb_buf+0x13f/0x230 fs/xfs/libxfs/xfs_sb.c:1490 xfs_ioc_setlabel+0x1de/0x340 fs/xfs/xfs_ioctl.c:1060 xfs_file_ioctl+0x9bf/0x16c0 fs/xfs/xfs_ioctl.c:1217 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 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: 0033:0x7f622e39cdd9 RSP: 002b:00007f622f187028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f622e616090 RCX: 00007f622e39cdd9 RDX: 0000200000000600 RSI: 0000000041009432 RDI: 0000000000000004 RBP: 00007f622e432d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f622e616128 R14: 00007f622e616090 R15: 00007ffed3146c78 Showing all locks held in the system: 1 lock held by khungtaskd/32: #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:4/67: #0: ffff88807e2b5140 ((wq_completion)xfs-cil/loop5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88807e2b5140 ((wq_completion)xfs-cil/loop5){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000205fc40 ((work_completion)(&ctx->push_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000205fc40 ((work_completion)(&ctx->push_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 2 locks held by getty/5590: #0: ffff888035ec10a0 (&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/0:4/5851: #0: ffff8880685b6140 ((wq_completion)xfs-sync/loop5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff8880685b6140 ((wq_completion)xfs-sync/loop5){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90004017c40 ((work_completion)(&(&log->l_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90004017c40 ((work_completion)(&(&log->l_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 1 lock held by syz-executor/11218: #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.5.6027/25144: #0: ffff88802a9ba410 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:537 1 lock held by syz-executor/26662: #0: ffff888022a8e0d8 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888022a8e0d8 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888022a8e0d8 (&type->s_umount_key#87){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 3 locks held by kworker/1:7/27187: #0: ffff88813fe57140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88813fe57140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90002597c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90002597c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff88805d9a5230 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11218 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline] RIP: 0010:delay_tsc+0x71/0xc0 arch/x86/lib/delay.c:72 Code: 00 00 e8 02 7d dc f5 65 8b 05 4b 59 89 07 85 c0 74 1c f3 90 bf 01 00 00 00 e8 4b 7b dc f5 e8 46 79 01 00 39 c5 75 0e 0f 01 f9 <66> 90 eb bd e8 26 54 7c f5 eb dd 4c 29 fb e8 2c 79 01 00 89 c5 0f RSP: 0018:ffffc90005ae7590 EFLAGS: 00000046 RAX: 00000000f862eb94 RBX: 0000000000000993 RCX: 0000000000000001 RDX: 00000000000002a8 RSI: ffffffff8c289b40 RDI: ffffffff8c289b00 RBP: 0000000000000001 R08: ffff888025848237 R09: 1ffff11004b09046 R10: dffffc0000000000 R11: ffffffff8bb77690 R12: 1ffffffff3503932 R13: 00000000ffffffff R14: 000002a8f862e715 R15: 00000000000003ec FS: 000055555f7dc500(0000) GS:ffff888125313000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe60924e90 CR3: 0000000077810000 CR4: 0000000000350ef0 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:1976 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline] serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 _btrfs_printk+0x29a/0x320 fs/btrfs/messages.c:236 btrfs_put_super+0x118/0x1c0 fs/btrfs/super.c:73 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_anon_super+0x3b/0x70 fs/super.c:1292 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2127 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:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f19f339e017 Code: a2 c7 05 dc 06 25 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:00007ffe609254e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f19f3432120 RCX: 00007f19f339e017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe609255a0 RBP: 00007ffe609255a0 R08: 00007ffe609265a0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe60926630 R13: 00007f19f3432120 R14: 00000000001225ec R15: 00007ffe60926670