INFO: task kworker/u8:16:5958 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:16 stat[ 564.202289][ T38] task:kworker/u8:16 state:D stack:22176 pid:5958 tgid:5958 ppid:2 task_flags:0x4248060 flags:0x00080000 Workqueue: xfs-cil/loop5 xlog_cil_push_work Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:268 [inline] __down_common+0x310/0x670 kernel/locking/semaphore.c:293 down+0x80/0xd0 kernel/locking/semaphore.c:100 xfs_buf_lock+0x14d/0x490 fs/xfs/xfs_buf.c:993 xfs_buf_item_unpin+0x1c4/0x6d0 fs/xfs/xfs_buf_item.c:556 xlog_cil_ail_insert fs/xfs/xfs_log_cil.c:-1 [inline] xlog_cil_committed+0x94c/0x1020 fs/xfs/xfs_log_cil.c:897 xlog_cil_push_work+0x1f2a/0x2560 fs/xfs/xfs_log_cil.c:1518 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 INFO: task syz.5.368:9288 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.368 state:D stack:27152 pid:9288 tgid:9248 ppid:7096 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x9a/0x270 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+0x2bf/0x5d0 kernel/sched/completion.c:153 __flush_workqueue+0x6f7/0x14b0 kernel/workqueue.c:4033 xlog_cil_push_now fs/xfs/xfs_log_cil.c:1636 [inline] xlog_cil_force_seq+0x22a/0x8f0 fs/xfs/xfs_log_cil.c:1838 xfs_log_force_seq+0x196/0x440 fs/xfs/xfs_log.c:3048 __xfs_trans_commit+0x7cc/0xbe0 fs/xfs/xfs_trans.c:879 xfs_trans_commit+0x13e/0x1c0 fs/xfs/xfs_trans.c:928 xfs_sync_sb_buf+0x134/0x230 fs/xfs/libxfs/xfs_sb.c:1487 xfs_ioc_setlabel fs/xfs/xfs_ioctl.c:1039 [inline] xfs_file_ioctl+0x14ab/0x17f0 fs/xfs/xfs_ioctl.c:1196 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc0defcf749 RSP: 002b:00007fc0dd20d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc0df226090 RCX: 00007fc0defcf749 RDX: 00002000000001c0 RSI: 0000000041009432 RDI: 0000000000000007 RBP: 00007fc0df053f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc0df226128 R14: 00007fc0df226090 R15: 00007fff9b4b61b8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by dhcpcd/5462: #0: ffffffff8e8899d8 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5f1/0x790 net/socket.c:1337 #1: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xd0/0x650 net/8021q/vlan.c:579 2 locks held by getty/5560: #0: ffff88803426f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:4/5885: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000563fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000563fbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff88801c348260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x224/0x3e0 drivers/net/netdevsim/fib.c:1490 3 locks held by kworker/0:5/5914: #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff55138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900056cfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900056cfbc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff88805b10c260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x224/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by kworker/u8:16/5958: #0: ffff88803944f938 ((wq_completion)xfs-cil/loop5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88803944f938 ((wq_completion)xfs-cil/loop5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900057efbc0 ((work_completion)(&ctx->push_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900057efbc0 ((work_completion)(&ctx->push_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 6 locks held by kworker/u8:20/6405: #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000588fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000588fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e898840 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670 #3: ffff8880555980d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff8880555980d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880555980d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506 #4: ffff888029092300 (&devlink->lock_key#19){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff888029092300 (&devlink->lock_key#19){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff888029092300 (&devlink->lock_key#19){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506 #5: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2143 3 locks held by kworker/u8:21/6516: #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000605fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000605fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by syz-executor/7107: #0: ffff888030e4c0d0 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888030e4c0d0 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888030e4c0d0 (&type->s_umount_key#87){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8d9f9978 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by kworker/1:8/7202: #0: ffff88803f753538 ((wq_completion)xfs-sync/loop5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88803f753538 ((wq_completion)xfs-sync/loop5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000472fbc0 ((work_completion)(&(&log->l_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000472fbc0 ((work_completion)(&(&log->l_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 1 lock held by syz.5.368/9288: #0: ffff88803f758480 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:543 2 locks held by syz-executor/9418: #0: ffff88805fac40d0 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805fac40d0 (&type->s_umount_key#87){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805fac40d0 (&type->s_umount_key#87){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8d9f9978 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 7 locks held by syz-executor/10802: #0: ffff8880346d4480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2681 [inline] #0: ffff8880346d4480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682 #1: ffff88805b0da878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff8880262f2e18 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff8880262f2e18 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e12c678 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184 #4: ffff88805b4d30d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88805b4d30d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x430 drivers/base/dd.c:1006 #5: ffff88805b10e300 (&devlink->lock_key#21){+.+.}-{4:4}, at: nsim_drv_probe+0xc3/0xbd0 drivers/net/netdevsim/dev.c:1637 #6: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2083 3 locks held by syz-executor/10984: 2 locks held by syz-executor/11026: #0: ffffffff8edb5e48 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8edb5e48 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8edb5e48 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8e8a5978 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071 2 locks held by syz.9.578/11048: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [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:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 4e da b5 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 bf 13 18 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90000167950 EFLAGS: 00000202 RAX: 1ffffffff31f3700 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff98f9c010 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8509d220 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff98f9bd80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126dee000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a4a855000 CR3: 000000003d2a0000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3109 [inline] console_flush_one_record+0x685/0xb80 kernel/printk/printk.c:3215 legacy_kthread_func+0x16f/0x210 kernel/printk/printk.c:3674 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246