INFO: task syz.0.328:6730 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.328 state:D stack:28704 pid:6730 tgid:6729 ppid:5846 task_flags:0x40054c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570 mmap_read_lock include/linux/mmap_lock.h:592 [inline] exit_mm+0x73/0x250 kernel/exit.c:557 do_exit+0x8b9/0x2490 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3035 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f23dc19c799 RSP: 002b:00007f23dd00a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: 0000000000000000 RBX: 00007f23dc415fa0 RCX: 00007f23dc19c799 RDX: 000000000000000d RSI: 0000000000000107 RDI: 0000000000000003 RBP: 00007f23dc232c99 R08: 000000000000001c R09: 0000000000000000 R10: 0000200000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f23dc416038 R14: 00007f23dc415fa0 R15: 00007fff4a0aecf8 INFO: task syz.0.328:6731 blocked for more than 143 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.328 state:D stack:21248 pid:6731 tgid:6729 ppid:5846 task_flags:0x40044c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570 mmap_read_lock include/linux/mmap_lock.h:592 [inline] exit_mm+0x73/0x250 kernel/exit.c:557 do_exit+0x8b9/0x2490 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3035 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f23dc19c799 RSP: 002b:00007f23dcfe9028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: fffffffffffffff2 RBX: 00007f23dc416090 RCX: 00007f23dc19c799 RDX: 0000000000000002 RSI: 0000200000000800 RDI: 0000000000000004 RBP: 00007f23dc232c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000004000840 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f23dc416128 R14: 00007f23dc416090 R15: 00007fff4a0aecf8 INFO: task syz.0.328:6733 blocked for more than 144 seconds. Tainted: G L syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.328 state:D stack:29328 pid:6733 tgid:6729 ppid:5846 task_flags:0x40044c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119 rwsem_down_read_slowpath+0x6d9/0x940 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x99/0x2e0 kernel/locking/rwsem.c:1570 mmap_read_lock include/linux/mmap_lock.h:592 [inline] exit_mm+0x73/0x250 kernel/exit.c:557 do_exit+0x8b9/0x2490 kernel/exit.c:962 do_group_exit+0x21b/0x2d0 kernel/exit.c:1116 get_signal+0x1284/0x1330 kernel/signal.c:3035 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] ret_from_fork+0x59d/0xb90 arch/x86/kernel/process.c:167 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: #0: ffff8880b853ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 6 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8eb5d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8eb5d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8eb5d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/0:3/996: #0: ffff88813fe03140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc9000520fc40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 #2: ffffffff8eb638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8eb638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by getty/5606: #0: ffff88803742a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/u9:3/5858: #0: ffff88802072b140 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc90004417c40 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 #2: ffff888035890ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open net/bluetooth/hci_core.c:429 [inline] #2: ffff888035890ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1ac/0x710 net/bluetooth/hci_core.c:960 6 locks held by kworker/0:5/5913: #0: ffff888021efb940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc90004737c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 #2: ffff88802a1f0190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline] #2: ffff88802a1f0190 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff88807a17d190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline] #3: ffff88807a17d190 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #4: ffff888078f21158 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline] #4: ffff888078f21158 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 #5: ffff8880767cda10 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:941 [inline] #5: ffff8880767cda10 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008 1 lock held by syz.0.328/6730: #0: ffff88807dd7dab8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88807dd7dab8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557 1 lock held by syz.0.328/6731: #0: ffff88807dd7dab8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88807dd7dab8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557 1 lock held by syz.0.328/6733: #0: ffff88807dd7dab8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88807dd7dab8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x73/0x250 kernel/exit.c:557 2 locks held by syz.2.2165/11792: #0: ffff888075cfb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline] #0: ffff888075cfb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:345 [inline] #0: ffff888075cfb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #0: ffff888075cfb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0xb8/0x520 drivers/tty/tty_ldisc.c:780 #1: ffff888075cfc0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: __tty_ldisc_lock_nested drivers/tty/tty_ldisc.c:295 [inline] #1: ffff888075cfc0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:347 [inline] #1: ffff888075cfc0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline] #1: ffff888075cfc0a0 (&tty->ldisc_sem/1){+.+.}-{0:0}, at: tty_ldisc_release+0xdc/0x520 drivers/tty/tty_ldisc.c:780 5 locks held by syz.5.2174/11823: #0: ffff888034108ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff888034108ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff8880341080b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346 #2: ffffffff90182a40 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff90182a40 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644 #3: ffff8880571f1af0 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 net/bluetooth/l2cap_core.c:1751 #4: ffffffff8eb638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #4: ffffffff8eb638e8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.1.2175/11821: ============================================= 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 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 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+0x1002/0x1060 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 5859 Comm: kworker/u9:4 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: hci3 hci_cmd_timeout RIP: 0010:__bfs_next kernel/locking/lockdep.c:1699 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1752 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x17a8/0x2cf0 kernel/locking/lockdep.c:5237 Code: 00 00 00 01 00 00 00 48 89 05 c4 ca c9 14 48 8d 84 24 90 00 00 00 48 89 05 b5 4a c9 14 31 ff 45 31 e4 4d 85 e4 4c 8b 6c 24 10 <74> 30 49 8b 44 24 30 48 85 c0 74 26 48 8b 40 10 48 83 c0 30 49 8b RSP: 0018:ffffc900044274a0 EFLAGS: 00000082 RAX: 0000000000000144 RBX: 0000000000000144 RCX: 0000000000000008 RDX: ffffffff940ee640 RSI: ffff88807c04c8c8 RDI: 0000000000000144 RBP: a30774b0a4053c4b R08: ffffc90004427468 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff81a35030 R12: ffffffff96f26bc8 R13: ffff88807c04c8f0 R14: ffff88807c04bd00 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888124de1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd0061af18 CR3: 000000000e94a000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 console_lock_spinning_enable kernel/printk/printk.c:1902 [inline] console_emit_next_record kernel/printk/printk.c:3177 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x6c1/0xb20 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 bt_err+0x121/0x180 net/bluetooth/lib.c:296 hci_cmd_timeout+0xd8/0x1e0 net/bluetooth/hci_core.c:1470 process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289 process_scheduled_works kernel/workqueue.c:3380 [inline] worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245