INFO: task syz.0.3018:16031 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.0.3018 state:D stack:27432 pid:16031 tgid:16030 ppid:14766 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5581 [inline] __schedule+0x1b47/0x5b40 kernel/sched/core.c:7384 __schedule_loop kernel/sched/core.c:7461 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7476 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7533 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821 write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874 nfsctl_transaction_write+0x10f/0x160 fs/nfsd/nfsctl.c:117 vfs_write+0x296/0xba0 fs/read_write.c:685 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f784939e159 RSP: 002b:00007f784a2ce028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7849625fa0 RCX: 00007f784939e159 RDX: 0000000000000005 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007f784943506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7849626038 R14: 00007f7849625fa0 R15: 00007ffeacc9cea8 Showing all locks held in the system: locks held by pr/ttyS0/16: 1, last CPU#0: #0: ffffffff8ec36118 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff8ec36118 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:493 [inline] #0: ffffffff8ec36118 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 locks held by khungtaskd/34: 1, last CPU#0: #0: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:2/45: 3, last CPU#0: #0: ffff888054663948 ((wq_completion)bond0#6){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888054663948 ((wq_completion)bond0#6){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888054663948 ((wq_completion)bond0#6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888054663948 ((wq_completion)bond0#6){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc90000b57c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000b57c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000b57c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc90000b57c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #2: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xf0/0x1840 drivers/net/bonding/bond_alb.c:1594 locks held by kworker/u8:5/101: 3, last CPU#0: #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc90002697c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90002697c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90002697c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc90002697c40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff88807e6ef258 (&devlink->lock_key#6){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834 locks held by kworker/u8:6/196: 3, last CPU#0: #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc9000304fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000304fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000304fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc9000304fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff888056693258 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834 locks held by kworker/u8:7/258: 3, last CPU#0: #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc9000310fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000310fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000310fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc9000310fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff88801fec4258 (&devlink->lock_key#5){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb30 drivers/net/netdevsim/dev.c:834 locks held by getty/5368: 2, on CPU#0: #0: ffff888031bb40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by kworker/u8:14/5892: 3, last CPU#0: #0: ffff888031588148 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888031588148 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888031588148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888031588148 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc90004c97c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004c97c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004c97c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc90004c97c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff888021ee21c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xd4/0xfc0 net/batman-adv/bat_iv_ogm.c:1010 locks held by syz-executor/13834: 1, on CPU#0: #0: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2cb/0x760 kernel/rcu/tree_exp.h:966 locks held by syz.5.3000/15981: 3, on CPU#0: #0: ffff8880767c5970 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1408 #1: ffff88807f10a460 (sb_writers#26){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff88807f10a460 (sb_writers#26){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f09fd40 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874 locks held by syz.0.3018/16031: 3, on CPU#0: #0: ffff888078e5b0b0 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x118/0x160 fs/file.c:1408 #1: ffff88803ca1e460 (sb_writers#26){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline] #1: ffff88803ca1e460 (sb_writers#26){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683 #2: ffffffff8f09fd40 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd10 fs/nfsd/nfsctl.c:874 locks held by syz-executor/16185: 4, last CPU#0: #0: ffffffff8ee38270 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline] #0: ffffffff8ee38270 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10a/0x470 kernel/fork.c:1594 #1: ffff888035021bc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline] #1: ffff888035021bc0 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716 #2: ffff88807f1dd900 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:538 [inline] #2: ffff88807f1dd900 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723 #3: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ed5c620 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302 locks held by kworker/0:8/16209: 6, on CPU#0: #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc900048ffc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc900048ffc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc900048ffc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc900048ffc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff88802952f1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802952f1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917 #3: ffff88802904a568 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3270 [inline] #3: ffff88802904a568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5482 [inline] #3: ffff88802904a568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #3: ffff88802904a568 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #3: ffff88802904a568 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20a1/0x4d30 drivers/usb/core/hub.c:5971 #4: ffff8880293ffb60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5483 [inline] #4: ffff8880293ffb60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #4: ffff8880293ffb60 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #4: ffff8880293ffb60 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20c9/0x4d30 drivers/usb/core/hub.c:5971 #5: ffffffff8fb057c8 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14d/0x1810 drivers/usb/core/hub.c:3085 locks held by kworker/0:9/16303: 5, last CPU#0: #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #0: ffff888022ef6148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #1: ffffc9000372fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000372fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000372fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3460 [inline] #1: ffffc9000372fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3578 #2: ffff88802904c1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802904c1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5917 #3: ffff888031ab51d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff888031ab51d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #4: ffff88803bcf01a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88803bcf01a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 locks held by udevd/16811: 1, last CPU#0: #0: ffff88802f7accc0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline] #0: ffff88802f7accc0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1dd/0x4e0 mm/util.c:579 locks held by udevd/16943: 3, on CPU#0: #0: ffff8880568d7580 (&type->i_mutex_dir_key#4){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff8880568d7580 (&type->i_mutex_dir_key#4){++++}-{4:4}, at: lookup_slow+0x46/0x80 fs/namei.c:1935 #1: ffff888075cda920 (DCACHE_PAR_LOOKUP){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffff888075cda920 (DCACHE_PAR_LOOKUP){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffff888075cda920 (DCACHE_PAR_LOOKUP){+.+.}-{0:0}, at: __d_alloc_parallel+0x39e/0x1700 fs/dcache.c:2881 #2: ffff88801c2dc980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_iop_lookup+0x5f/0x320 fs/kernfs/dir.c:1258 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:377 [inline] watchdog+0x1058/0x10d0 kernel/hung_task.c:598 kthread+0x38b/0x480 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