INFO: task kworker/1:0:13741 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/1:0 state:D stack:23416 pid:13741 tgid:13741 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: xfs-sync/loop8 xfs_flush_inodes_worker Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 wb_wait_for_completion+0x3b2/0x700 fs/fs-writeback.c:227 sync_inodes_sb+0x226/0xc30 fs/fs-writeback.c:3030 xfs_flush_inodes_worker+0x61/0x80 fs/xfs/xfs_super.c:667 process_one_work+0x93a/0x12b0 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3490 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.8.1390:15927 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1390 state:D stack:22000 pid:15927 tgid:15910 ppid:7348 task_flags:0x400640 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0xc0/0x2c0 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+0x2ca/0x5e0 kernel/sched/completion.c:153 __flush_work+0x9c2/0xd70 kernel/workqueue.c:4378 xfs_file_buffered_write+0x27c/0x880 fs/xfs/xfs_file.c:1079 __kernel_write_iter+0x453/0x8f0 fs/read_write.c:621 dump_emit_page fs/coredump.c:1298 [inline] dump_user_range+0xc1c/0x12c0 fs/coredump.c:1372 elf_core_dump+0x3485/0x3a90 fs/binfmt_elf.c:2109 coredump_write+0x129c/0x1960 fs/coredump.c:1052 do_coredump fs/coredump.c:1131 [inline] vfs_coredump+0x3705/0x44c0 fs/coredump.c:1200 get_signal+0x1094/0x12c0 kernel/signal.c:3023 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __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:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2fca2fce59 RSP: 002b:00007f2fc85350e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f2fca576098 RCX: 00007f2fca2fce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2fca57609c RBP: 00007f2fca576090 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2fca576128 R14: 00007fff3f669050 R15: 00007fff3f669138 Showing all locks held in the system: 4 locks held by pr/legacy/17: #0: ffffffff8dfb5200 (console_lock){+.+.}-{0:0}, at: legacy_kthread_func+0x1a3/0x250 kernel/printk/printk.c:3711 #1: ffffffff8de9caf8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:305 [inline] #1: ffffffff8de9caf8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:428 [inline] #1: ffffffff8de9caf8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:291 [inline] #1: ffffffff8de9caf8 (console_srcu){....}-{0:0}, at: console_flush_one_record+0xfa/0xb50 kernel/printk/printk.c:3246 #2: ffffffff99bb7c98 (&port_lock_key){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffffffff99bb7c98 (&port_lock_key){+.+.}-{3:3}, at: uart_port_lock_irqsave include/linux/serial_core.h:719 [inline] #2: ffffffff99bb7c98 (&port_lock_key){+.+.}-{3:3}, at: serial8250_console_write+0x17c/0x1b40 drivers/tty/serial/8250/8250_port.c:3338 #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 1 lock held by khungtaskd/39: #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777 10 locks held by kworker/u8:3/57: #0: ffff88801b696138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc9000123fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8f378900 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0 net/core/net_namespace.c:248 #4: ffffffff8de591a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #5: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #6: ffff8880353d8328 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline] #6: ffff8880353d8328 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: dev_reset_queue+0x144/0x1f0 include/net/sch_generic.h:752 #7: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #7: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #7: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #7: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #8: ffffffff8de591a0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #9: ffff8880353d8230 (&sch->root_lock_key#9){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline] #9: ffff8880353d8230 (&sch->root_lock_key#9){+...}-{3:3}, at: dev_reset_queue+0x160/0x1f0 include/net/sch_generic.h:753 3 locks held by kworker/u8:4/67: #0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc9000152fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 4 locks held by kworker/u8:15/3329: #0: ffff88801b6bc938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc9000fa37c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffff8880616ce7f0 (sb_internal#4){.+.+}-{0:0}, at: xfs_trans_alloc+0xcf/0x990 fs/xfs/xfs_trans.c:254 #3: ffff888062754d78 (&xfs_nondir_ilock_class#2){++++}-{4:4}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4380 [inline] #3: ffff888062754d78 (&xfs_nondir_ilock_class#2){++++}-{4:4}, at: xfs_bmapi_convert_delalloc+0x370/0x1540 fs/xfs/libxfs/xfs_bmap.c:4501 2 locks held by getty/5366: #0: ffff8880360e40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:3/5600: #0: ffff88813fe4b938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc900044c7c60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 5 locks held by kworker/u8:20/6330: #0: ffff88813fe8c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc90007d6fc60 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffff88802676e310 (&devlink->lock_key#18){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xcb0 drivers/net/netdevsim/dev.c:909 #3: ffff88805f5c6920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffff88805f5c6920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:862 [inline] #3: ffff88805f5c6920 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1e0/0xcb0 drivers/net/netdevsim/dev.c:922 #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #4: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 4 locks held by kworker/u9:1/10616: #0: ffff88802ce85138 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc90004c17c60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffff888060730f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331 #3: ffff8880607300b0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0xa6f/0x1190 net/bluetooth/hci_sync.c:5786 4 locks held by kworker/1:0/13741: #0: ffff888061bc3138 ((wq_completion)xfs-sync/loop8){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #1: ffffc90004627c60 ((work_completion)(&mp->m_flush_inodes_work)){+.+.}-{0:0}, at: process_one_work+0x8cd/0x12b0 kernel/workqueue.c:3301 #2: ffff8880616ce0d0 (&type->s_umount_key#75){++++}-{4:4}, at: xfs_flush_inodes_worker+0x45/0x80 fs/xfs/xfs_super.c:666 #3: ffff888026954920 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline] #3: ffff888026954920 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x20f/0xc30 fs/fs-writeback.c:3028 1 lock held by syz-executor/15822: #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline] #0: ffffffff8dfc3040 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 7 locks held by syz-executor/15830: #0: ffff8880357ee500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2728 [inline] #0: ffff8880357ee500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88803c540878 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff888029e22b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888029e22b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ebfce78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff888059588160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff888059588160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff888059588160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffff8880639fc310 (&devlink->lock_key#41){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799 #6: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #6: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2164 2 locks held by syz.8.1390/15927: #0: ffff8880616ce500 (sb_writers#23){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1131 [inline] #0: ffff8880616ce500 (sb_writers#23){.+.+}-{0:0}, at: vfs_coredump+0x3705/0x44c0 fs/coredump.c:1200 #1: ffff888062755000 (&sb->s_type->i_mutex_key#34){++++}-{4:4}, at: xfs_ilock+0xee/0x380 fs/xfs/xfs_inode.c:149 2 locks held by syz-executor/15937: #0: ffffffff8f378900 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575 #1: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11553 2 locks held by syz-executor/15945: #0: ffffffff8f378900 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:575 #1: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline] #1: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11553 1 lock held by syz-executor/15952: #0: ffffffff8f387f38 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bf/0x1e30 drivers/net/tun.c:3148 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 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: 17 Comm: pr/legacy Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 8e 60 81 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 af 3a ed fc 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:ffffc90000167a28 EFLAGS: 00000202 RAX: 1ffffffff3376f00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8543b7a0 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99bb7cc0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125fd4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd7202b37e8 CR3: 000000002a3bc000 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+0x190/0x300 drivers/tty/serial/8250/8250_port.c:1982 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3229 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3294 [inline] serial8250_console_write+0x113a/0x1b40 drivers/tty/serial/8250/8250_port.c:3379 console_emit_next_record kernel/printk/printk.c:3163 [inline] console_flush_one_record+0x642/0xb50 kernel/printk/printk.c:3269 legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712 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