INFO: task syz.3.1399:12668 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.3.1399 state:D stack:27560 pid:12668 tgid:12665 ppid:5638 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2738 __sys_sendmsg+0x160/0x210 net/socket.c:2770 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1640f9ce59 RSP: 002b:00007f1641ef5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f1641216090 RCX: 00007f1640f9ce59 RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000003 RBP: 00007f1641032e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1641216128 R14: 00007f1641216090 R15: 00007ffff08cd0c8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 1 lock held by sshd-session/5610: 2 locks held by syz-executor/5624: #0: ffff88801fe9c0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88801fe9c0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88801fe9c0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff88801fe9c0d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 3 locks held by kworker/u8:43/10180: #0: ffff88803346b140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90004a4fd08 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4769 3 locks held by kworker/u8:52/10190: #0: ffff88813feac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90003f27d08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313 2 locks held by getty/11525: #0: ffff888033d9d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000533d2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/11692: #0: ffff8880325f40d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880325f40d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880325f40d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff8880325f40d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 2 locks held by syz.3.1399/12667: #0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964 2 locks held by syz.3.1399/12668: #0: ffffffff906efda8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964 2 locks held by syz-executor/12896: #0: ffff8880766900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880766900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880766900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff8880766900d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 2 locks held by syz-executor/13015: #0: ffff8880485600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880485600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880485600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff8880485600d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 3 locks held by kworker/0:5/13200: #0: ffff88813fe6b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc9000342fd08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff8e7f1968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 2 locks held by syz-executor/13409: #0: ffff888034f160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888034f160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888034f160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super fs/super.c:509 [inline] #0: ffff888034f160d8 (&type->s_umount_key#53){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506 #1: ffffffff8ec6ef00 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576 1 lock held by syz-executor/14666: #0: ffff888050a28ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497 1 lock held by syz-executor/14677: #0: ffffffff8e7f1968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 8 locks held by syz-executor/14891: #0: ffff88807f930450 (sb_writers#7){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739 #1: ffff888033ccf080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336 #2: ffff888029fd51e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff888029fd51e8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:337 #3: ffffffff8fbafc20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x480 drivers/net/netdevsim/bus.c:234 #4: ffff88807fc6f128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #4: ffff88807fc6f128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88807fc6f128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369 #5: ffff88807fc6e258 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_drv_remove+0x4a/0x1e0 drivers/net/netdevsim/dev.c:1799 #6: ffffffff90641500 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x19e/0x970 drivers/net/netdevsim/netdev.c:1189 #7: ffff888059cf4e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2847 [inline] #7: ffff888059cf4e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x47f/0x2140 net/core/dev.c:12400 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 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+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 14677 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__bfs+0x1c7/0x2a0 kernel/locking/lockdep.c:1815 Code: 81 e3 ff 0f 00 00 39 1d 27 2d 36 14 48 89 04 f5 80 5e d5 96 73 11 89 1d 17 2d 36 14 eb 09 0f 1f 44 00 00 4c 89 78 30 48 8b 00 <4c> 39 c0 75 f4 e9 22 ff ff ff b8 01 00 00 00 48 83 c4 30 5b 5d 41 RSP: 0018:ffffc9000d86eea8 EFLAGS: 00000006 RAX: ffffffff9621a940 RBX: 0000000000000168 RCX: 0000000000000169 RDX: ffffffff9621a910 RSI: 0000000000000169 RDI: ffffffff97b1ccd8 RBP: 0000000000000030 R08: ffffffff9621a940 R09: 0000000000000002 R10: ffffc9000d86f040 R11: 0000000000000000 R12: ffffffff81e413e0 R13: ffffc9000d86ef50 R14: ffffffff81e421f0 R15: ffffffff97b1ccd8 FS: 0000000000000000(0000) GS:ffff8881242e7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8517f02000 CR3: 0000000068d4c000 CR4: 00000000003526f0 Call Trace: __bfs_backwards kernel/locking/lockdep.c:1860 [inline] check_irq_usage+0xe5/0x810 kernel/locking/lockdep.c:2796 check_prev_add+0xfe/0xe60 kernel/locking/lockdep.c:3169 check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x136c/0x1a40 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 seqcount_lockdep_reader_access include/linux/seqlock.h:73 [inline] ktime_get+0x7c/0x320 kernel/time/timekeeping.c:971 hrtick_schedule_exit kernel/sched/core.c:1000 [inline] finish_lock_switch kernel/sched/core.c:5240 [inline] finish_task_switch.isra.0+0x94b/0x10c0 kernel/sched/core.c:5359 context_switch kernel/sched/core.c:5513 [inline] __schedule+0x1264/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_release+0x4/0x310 kernel/locking/lockdep.c:5876 Code: 44 8b 4c 24 18 4c 8b 54 24 10 44 8b 5c 24 0c eb 98 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <41> 57 41 56 41 54 55 53 48 89 fb 48 83 ec 18 65 48 8b 2d 7d 01 2f RSP: 0018:ffffc9000d86f4e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff821a227e RDX: ffff888034559f00 RSI: ffffffff821a21da RDI: ffffffff8e7e5ec0 RBP: 00007f4b1a79ce00 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81f30580 R13: ffffc9000d86f600 R14: 0000000000000000 R15: ffff888034559f00 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] is_bpf_text_address+0x8f/0x1a0 kernel/bpf/core.c:749 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x8d/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xa6/0xf0 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5515 _kmalloc_noprof include/linux/slab.h:969 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] kobject_uevent_env+0x263/0x18b0 lib/kobject_uevent.c:543 device_del+0x605/0x9b0 drivers/base/core.c:3979 device_unregister+0x1d/0xe0 drivers/base/core.c:4002 hci_conn_del_sysfs+0xb9/0x1a0 net/bluetooth/hci_sysfs.c:79 hci_conn_cleanup net/bluetooth/hci_conn.c:170 [inline] hci_conn_del+0x506/0x1180 net/bluetooth/hci_conn.c:1306 hci_conn_hash_flush+0x186/0x280 net/bluetooth/hci_conn.c:2734 hci_dev_close_sync+0x5cf/0x13c0 net/bluetooth/hci_sync.c:5405 hci_dev_do_close+0x2e/0xb0 net/bluetooth/hci_core.c:499 hci_unregister_dev+0x23f/0x690 net/bluetooth/hci_core.c:2678 vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:700 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x951/0x2ae0 kernel/exit.c:1004 do_group_exit+0xd5/0x2a0 kernel/exit.c:1147 __do_sys_exit_group kernel/exit.c:1158 [inline] __se_sys_exit_group kernel/exit.c:1156 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1156 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4b1a79ce59 Code: Unable to access opcode bytes at 0x7f4b1a79ce2f. RSP: 002b:00007ffe741e00a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f4b1a833db7 RCX: 00007f4b1a79ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007f4b1a833dc9 R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00000000000927c0 R14: 00000000000a7a4a R15: 00007ffe741e0250