INFO: task syz.0.3058:20293 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.3058 state:D stack:26744 pid:20293 tgid:20289 ppid:19283 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 bdev_open+0xa2/0xe40 block/bdev.c:945 bdev_file_open_by_dev block/bdev.c:1059 [inline] bdev_file_open_by_dev+0x182/0x210 block/bdev.c:1034 setup_bdev_super+0x39b/0x730 fs/super.c:1609 get_tree_bdev_flags+0x363/0x620 fs/super.c:1689 vfs_get_tree+0x8e/0x340 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount fs/namespace.c:3727 [inline] path_mount+0x7b9/0x23a0 fs/namespace.c:4037 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount fs/namespace.c:4215 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe2fef8f6c9 RSP: 002b:00007fe2fff00038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe2ff1e5fa0 RCX: 00007fe2fef8f6c9 RDX: 0000200000000080 RSI: 0000200000000000 RDI: 0000200000000140 RBP: 00007fe2ff011f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000208000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe2ff1e6038 R14: 00007fe2ff1e5fa0 R15: 00007ffed2b61d38 Showing all locks held in the system: 5 locks held by kworker/1:0/24: #0: ffff88801e2ab548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900001e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff888144f88198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888144f88198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888144f8b518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff888144f8b518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff888144f8b518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff888144f8b518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff888144f8b518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2981/0x4fe0 drivers/usb/core/hub.c:5952 #4: ffff8881447f3e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #4: ffff8881447f3e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #4: ffff8881447f3e68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #4: ffff8881447f3e68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x29aa/0x4fe0 drivers/usb/core/hub.c:5952 1 lock held by khungtaskd/31: #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 2 locks held by getty/5572: #0: ffff888035e9d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:4/5872: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90002ef7d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff8e3cfcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 5 locks held by kworker/1:8/5964: #0: ffff88801e2ab548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900053d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff8880296d0198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff8880296d0198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff8880296d3518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff8880296d3518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff8880296d3518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff8880296d3518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff8880296d3518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2981/0x4fe0 drivers/usb/core/hub.c:5952 #4: ffff8880295aad68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #4: ffff8880295aad68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #4: ffff8880295aad68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #4: ffff8880295aad68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x29aa/0x4fe0 drivers/usb/core/hub.c:5952 1 lock held by udevd/9930: #0: ffff888026390358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 2 locks held by syz.0.3058/20293: #0: ffff888027bd20e0 (&type->s_umount_key#90/1){+.+.}-{4:4}, at: alloc_super+0x1e3/0xb60 fs/super.c:344 #1: ffff888026390358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:945 4 locks held by syz.5.3404/25411: #0: ffff88804b0e8dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff88804b0e80b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5296 #2: ffffffff9035b0c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2119 [inline] #2: ffffffff9035b0c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2609 #3: ffff888029e38338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 3 locks held by syz.2.3405/25499: #0: ffff8880498bcdc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff8880498bc0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5296 #2: ffffffff9035b0c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2119 [inline] #2: ffffffff9035b0c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2609 1 lock held by syz.9.3406/25424: #0: ffffffff900e7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff900e7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436 3 locks held by syz.8.3334/25469: #0: ffff888045774dc8 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff8880457740b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5296 #2: ffffffff9035b0c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2119 [inline] #2: ffffffff9035b0c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2609 1 lock held by syz.4.3407/25482: #0: ffffffff8e3cfcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by dhcpcd-run-hook/25527: #0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline] #0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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: 25424 Comm: syz.9.3406 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:391 [inline] RIP: 0010:__rcu_read_lock+0x6f/0xf0 kernel/rcu/tree_plugin.h:414 Code: ff 11 48 8d bd 84 04 00 00 8b 9b 84 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 83 c3 01 0f b6 14 02 48 89 f8 <83> e0 07 83 c0 03 38 d0 7c 04 84 d2 75 61 48 b8 00 00 00 00 00 fc RSP: 0018:ffffc90000a08a70 EFLAGS: 00000202 RAX: ffff8880789c4d84 RBX: 0000000000000001 RCX: ffffc90000a08a4c RDX: 0000000000000000 RSI: ffffffff817d4e70 RDI: ffff8880789c4d84 RBP: ffff8880789c4900 R08: ffffffff91169c66 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000007d4d R12: ffffffff81a80530 R13: ffffc90000a08af8 R14: 0000000000000000 R15: ffff8880789c4900 FS: 0000000000000000(0000) GS:ffff888124b08000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef5da1f9c CR3: 0000000028bcf000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:865 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xae/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:311 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 pagetable_free include/linux/mm.h:2997 [inline] pagetable_dtor_free include/linux/mm.h:3100 [inline] __tlb_remove_table include/asm-generic/tlb.h:220 [inline] __tlb_remove_table_free mm/mmu_gather.c:227 [inline] tlb_remove_table_rcu+0x121/0x320 mm/mmu_gather.c:290 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x1530 kernel/rcu/tree.c:2861 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:510 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] rt6_uncached_list_flush_dev net/ipv6/route.c:193 [inline] rt6_disable_ip+0x652/0x990 net/ipv6/route.c:5009 addrconf_ifdown.isra.0+0x11d/0x1aa0 net/ipv6/addrconf.c:3853 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3776 notifier_call_chain+0xbc/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2229 call_netdevice_notifiers_extack net/core/dev.c:2267 [inline] call_netdevice_notifiers net/core/dev.c:2281 [inline] netif_close_many+0x319/0x630 net/core/dev.c:1784 unregister_netdevice_many_notify+0x549/0x25c0 net/core/dev.c:12254 unregister_netdevice_many net/core/dev.c:12347 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:12161 unregister_netdevice include/linux/netdevice.h:3389 [inline] __tun_detach+0x119c/0x1490 drivers/net/tun.c:621 tun_detach drivers/net/tun.c:637 [inline] tun_chr_close+0xc2/0x230 drivers/net/tun.c:3436 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:966 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fad1478f6c9 Code: Unable to access opcode bytes at 0x7fad1478f69f. RSP: 002b:00007fad1558b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fad149e6098 RCX: 00007fad1478f6c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fad149e6098 RBP: 00007fad149e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fad149e6128 R14: 00007fffe39b9660 R15: 00007fffe39b9748