INFO: task syz.0.2769:17115 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2769 state:D stack:26808 pid:17115 tgid:17113 ppid:5844 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760 bdev_open+0x41a/0xe40 block/bdev.c:945 blkdev_open+0x34e/0x4f0 block/fops.c:694 do_dentry_open+0x982/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4046 do_filp_open+0x20b/0x470 fs/namei.c:4073 do_sys_openat2+0x11b/0x1d0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2228d8d510 RSP: 002b:00007f2229cd8b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000002400 RCX: 00007f2228d8d510 RDX: 0000000000002400 RSI: 00007f2229cd8c10 RDI: 00000000ffffff9c RBP: 00007f2229cd8c10 R08: 0000000000000000 R09: 002364626e2f7665 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f2228fd6038 R14: 00007f2228fd5fa0 R15: 00007ffc6fcc4038 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c1260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/1:1/54: #0: ffff88801b878d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90000be7d10 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff8e5cc7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/u8:10/3620: #0: ffff8880b843a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:644 [inline] #0: ffff8880b843a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:629 #1: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #1: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6955 #2: ffff8880b8525b18 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x127/0x1d0 kernel/time/timer.c:1004 5 locks held by kworker/0:3/5900: #0: ffff888022a86d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc900043cfd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888144b00198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff888144b00198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff888144b03518 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3251 [inline] #3: ffff888144b03518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5463 [inline] #3: ffff888144b03518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #3: ffff888144b03518 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #3: ffff888144b03518 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2981/0x4fe0 drivers/usb/core/hub.c:5952 #4: ffff888144759668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #4: ffff888144759668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] #4: ffff888144759668 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5870 [inline] #4: ffff888144759668 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x29aa/0x4fe0 drivers/usb/core/hub.c:5952 2 locks held by getty/8152: #0: ffff8880323190a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc90003da32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by udevd/16202: #0: ffff888142b10358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 1 lock held by syz.0.2769/17115: #0: ffff888142b10358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 3 locks held by syz-executor/17270: #0: ffff888074dfcdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff888074dfc0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5282 #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2599 1 lock held by syz-executor/17351: #0: ffffffff8e5cc7f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by syz-executor/18119: #0: ffff88803926cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff88803926c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5282 #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2599 3 locks held by syz-executor/18554: #0: ffff8880412e4dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff8880412e40b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5282 #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2599 4 locks held by syz.1.3212/19027: #0: ffff888038e94dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:499 #1: ffff888038e940b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ae/0x11d0 net/bluetooth/hci_sync.c:5282 #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2094 [inline] #2: ffffffff905ed168 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x260 net/bluetooth/hci_conn.c:2599 #3: ffff8880595dd338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x730 net/bluetooth/l2cap_core.c:1762 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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:328 [inline] watchdog+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 17351 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:__lock_acquire+0x182/0x1ce0 kernel/locking/lockdep.c:5171 Code: 54 24 10 45 89 c8 41 0f b7 44 24 20 4d 89 7c 24 10 4c 89 e7 66 81 e2 ff 1f 49 89 6c 24 18 66 25 00 e0 09 d0 66 41 89 44 24 20 <48> 8b 84 24 b0 00 00 00 49 89 44 24 08 41 8b b5 d4 0a 00 00 31 c0 RSP: 0018:ffffc900101a7570 EFLAGS: 00000002 RAX: 0000000000000007 RBX: ffff888037285370 RCX: 0000000000000002 RDX: 0000000000000007 RSI: 0000000000000000 RDI: ffff888037285370 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff888037285370 R13: ffff888037284880 R14: 0000000000000000 R15: ffffffff8e5c1260 FS: 0000000000000000(0000) GS:ffff8881246b5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b15873bb48 CR3: 000000003389e000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] is_module_text_address+0x33/0x220 kernel/module/main.c:3845 kernel_text_address kernel/extable.c:119 [inline] kernel_text_address+0x81/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26 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:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 vfree+0x1fd/0xb50 mm/vmalloc.c:3434 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x3ff/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:961 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x84/0x110 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+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f883698fed7 Code: Unable to access opcode bytes at 0x7f883698fead. RSP: 002b:00007fff529aefb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f8836a11c05 RCX: 00007f883698fed7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff529af070 RBP: 00007fff529af070 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff529b0100 R13: 00007f8836a11c05 R14: 000000000012f7de R15: 00007fff529b0140