INFO: task syz.2.969:9653 blocked for more than 143 seconds. Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.969 state:D stack:27288 pid:9653 tgid:9647 ppid:5856 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 __flush_work+0x9b9/0xbc0 kernel/workqueue.c:4246 __cancel_work_sync+0xbe/0x110 kernel/workqueue.c:4366 hidp_session_remove+0x62/0x260 net/bluetooth/hidp/core.c:1169 l2cap_unregister_user+0x18e/0x1b0 net/bluetooth/l2cap_core.c:1734 hidp_connection_del+0xb0/0x170 net/bluetooth/hidp/core.c:1409 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:97 [inline] hidp_sock_ioctl+0x317/0x560 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa93c78e9a9 RSP: 002b:00007fa93d629038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa93c9b6080 RCX: 00007fa93c78e9a9 RDX: 0000200000000000 RSI: 00000000400448c9 RDI: 0000000000000006 RBP: 00007fa93c810d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa93c9b6080 R15: 00007ffdfee45f78 INFO: task khidpd_00005505:9654 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khidpd_00005505 state:D stack:29416 pid:9654 tgid:9654 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1728 hidp_session_thread+0x3c9/0x410 net/bluetooth/hidp/core.c:1304 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.3.1025:9836 blocked for more than 144 seconds. Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1025 state:D stack:26280 pid:9836 tgid:9835 ppid:5849 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 hidp_session_find+0x1a/0x100 net/bluetooth/hidp/core.c:1026 hidp_get_conninfo+0x17/0x50 net/bluetooth/hidp/core.c:1450 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:116 [inline] hidp_sock_ioctl+0x2a2/0x560 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae97b8e9a9 RSP: 002b:00007fae98aaf038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fae97db5fa0 RCX: 00007fae97b8e9a9 RDX: 0000200000000500 RSI: 00000000800448d3 RDI: 0000000000000006 RBP: 00007fae97c10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fae97db5fa0 R15: 00007ffff7469fe8 INFO: task syz.4.1040:9889 blocked for more than 145 seconds. Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.1040 state:D stack:27208 pid:9889 tgid:9888 ppid:5857 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084 __down_read_common kernel/locking/rwsem.c:1248 [inline] __down_read kernel/locking/rwsem.c:1261 [inline] down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526 hidp_session_find+0x1a/0x100 net/bluetooth/hidp/core.c:1026 hidp_get_conninfo+0x17/0x50 net/bluetooth/hidp/core.c:1450 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:116 [inline] hidp_sock_ioctl+0x2a2/0x560 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5d9398e9a9 RSP: 002b:00007f5d9470e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5d93bb5fa0 RCX: 00007f5d9398e9a9 RDX: 0000200000002f00 RSI: 00000000800448d3 RDI: 000000000000000d RBP: 00007f5d93a10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5d93bb5fa0 R15: 00007fff07814698 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5610: #0: ffff888033a600a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/u9:4/5860: #0: ffff888034b49948 ((wq_completion)hci4#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888034b49948 ((wq_completion)hci4#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90003fefbc0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003fefbc0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888020b280b8 (&hdev->lock){+.+.}-{4:4}, at: hci_link_tx_to net/bluetooth/hci_core.c:3459 [inline] #2: ffff888020b280b8 (&hdev->lock){+.+.}-{4:4}, at: __check_timeout+0x16f/0x2f0 net/bluetooth/hci_core.c:3606 4 locks held by kworker/0:12/7808: 2 locks held by syz.2.969/9653: #0: ffff888020b280b8 (&hdev->lock){+.+.}-{4:4}, at: l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1728 #1: ffffffff8f6ad510 (hidp_session_sem){++++}-{4:4}, at: hidp_session_remove+0x2c/0x260 net/bluetooth/hidp/core.c:1165 1 lock held by khidpd_00005505/9654: #0: ffff888020b280b8 (&hdev->lock){+.+.}-{4:4}, at: l2cap_unregister_user+0x6a/0x1b0 net/bluetooth/l2cap_core.c:1728 1 lock held by syz.3.1025/9836: #0: ffffffff8f6ad510 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1a/0x100 net/bluetooth/hidp/core.c:1026 1 lock held by syz.4.1040/9889: #0: ffffffff8f6ad510 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1a/0x100 net/bluetooth/hidp/core.c:1026 1 lock held by syz.6.1253/10714: #0: ffffffff8f6ad510 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1a/0x100 net/bluetooth/hidp/core.c:1026 1 lock held by syz.7.1984/13258: #0: ffffffff8f6ad510 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1a/0x100 net/bluetooth/hidp/core.c:1026 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 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: 7808 Comm: kworker/0:12 Not tainted 6.16.0-rc7-syzkaller-00100-gafd8c2c9e2e2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events hidp_session_dev_work RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 2e f9 79 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 0f 0b dc fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 8a 55 2a 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900046debf0 EFLAGS: 00000002 RAX: 1ffffffff33bec00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99df6590 R08: ffff8880245e0237 R09: 1ffff110048bc046 R10: dffffc0000000000 R11: ffffffff85462d50 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99df6300 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561c5f62d168 CR3: 000000007f666000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:2094 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x725/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4917 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4928 _dev_warn+0x10a/0x160 drivers/base/core.c:4984 hid_parser_main+0x8b8/0xc40 drivers/hid/hid-core.c:-1 hid_open_report+0x858/0xee0 drivers/hid/hid-core.c:1328 hid_parse include/linux/hid.h:1133 [inline] hid_generic_probe+0x3d/0x90 drivers/hid/hid-generic.c:66 __hid_device_probe drivers/hid/hid-core.c:2733 [inline] hid_device_probe+0x39d/0x710 drivers/hid/hid-core.c:2770 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26d/0x9a0 drivers/base/dd.c:657 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1029 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3692 hid_add_device+0x398/0x540 drivers/hid/hid-core.c:2916 hidp_session_dev_add net/bluetooth/hidp/core.c:856 [inline] hidp_session_dev_work+0x45/0x160 net/bluetooth/hidp/core.c:895 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245