INFO: task syz.3.454:7501 blocked for more than 143 seconds. Not tainted 6.14.0-syzkaller-05884-g2ea396448f26 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.454 state:D stack:26848 pid:7501 tgid:7498 ppid:5831 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1b18/0x50e0 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0x163/0x360 kernel/sched/core.c:6839 schedule_timeout+0xb1/0x290 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+0x360/0x630 kernel/sched/completion.c:148 __flush_work+0xa48/0xc60 kernel/workqueue.c:4244 __cancel_work_sync+0xbc/0x110 kernel/workqueue.c:4364 hidp_session_remove+0x64/0x260 net/bluetooth/hidp/core.c:1169 l2cap_unregister_user+0x19c/0x1c0 net/bluetooth/l2cap_core.c:1733 hidp_connection_del+0xb0/0x160 net/bluetooth/hidp/core.c:1409 do_hidp_sock_ioctl net/bluetooth/hidp/sock.c:97 [inline] hidp_sock_ioctl+0x42b/0x8c0 net/bluetooth/hidp/sock.c:128 sock_do_ioctl+0x15a/0x490 net/socket.c:1190 sock_ioctl+0x644/0x900 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f559498d169 RSP: 002b:00007f559574b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f5594ba5fa0 RCX: 00007f559498d169 RDX: 0000200000000000 RSI: 00000000400448c9 RDI: 000000000000000c RBP: 00007f5594a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5594ba5fa0 R15: 00007fffbc86c398 INFO: task khidpd_04570009:7505 blocked for more than 144 seconds. Not tainted 6.14.0-syzkaller-05884-g2ea396448f26 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khidpd_04570009 state:D stack:29792 pid:7505 tgid:7505 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1b18/0x50e0 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0x163/0x360 kernel/sched/core.c:6839 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6896 __mutex_lock_common kernel/locking/mutex.c:664 [inline] __mutex_lock+0x7fa/0x1000 kernel/locking/mutex.c:732 l2cap_unregister_user+0x6a/0x1c0 net/bluetooth/l2cap_core.c:1727 hidp_session_thread+0x450/0x490 net/bluetooth/hidp/core.c:1304 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ed3a260 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3a260 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3a260 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761 4 locks held by kworker/u8:2/36: #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000ad7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000ad7c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900d8bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17c/0xd60 net/core/net_namespace.c:608 #3: ffffffff8ed3f640 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 4 locks held by kworker/u9:0/56: #0: ffff88802895b148 ( (wq_completion)hci4 ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3213 [inline] , at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000101fc60 ( (work_completion)(&hdev->cmd_sync_work) ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3214 [inline] , at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff88805fc80d80 ( &hdev->req_lock ){+.+.}-{4:4} , at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331 #3: ffff88805fc80078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1f1/0xeb0 net/bluetooth/hci_sync.c:5597 2 locks held by getty/5589: #0: ffff88814d2810a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211 8 locks held by kworker/0:6/5913: 2 locks held by syz.3.454/7501: #0: ffff88805fc80078 (&hdev->lock){+.+.}-{4:4}, at: l2cap_unregister_user+0x6a/0x1c0 net/bluetooth/l2cap_core.c:1727 #1: ffffffff902744f0 (hidp_session_sem){++++}-{4:4}, at: hidp_session_remove+0x2d/0x260 net/bluetooth/hidp/core.c:1165 1 lock held by khidpd_04570009/7505: #0: ffff88805fc80078 (&hdev->lock){+.+.}-{4:4}, at: l2cap_unregister_user+0x6a/0x1c0 net/bluetooth/l2cap_core.c:1727 1 lock held by syz.4.674/8252: #0: ffff88805fc80078 ( &hdev->lock ){+.+.}-{4:4} , at: l2cap_chan_connect+0x102/0xea0 net/bluetooth/l2cap_core.c:6954 1 lock held by syz.6.1095/9624: #0: ffffffff902744f0 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1c/0x110 net/bluetooth/hidp/core.c:1026 1 lock held by syz.6.1095/9627: #0: ffffffff902744f0 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1c/0x110 net/bluetooth/hidp/core.c:1026 1 lock held by syz.1.1131/9765: #0: ffffffff902744f0 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1c/0x110 net/bluetooth/hidp/core.c:1026 3 locks held by syz-executor/9931: #0: ffff88804cdc4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff88804cdc4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2678 #1: ffff88804cdc4078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60f/0x1260 net/bluetooth/hci_sync.c:5213 #2: ffffffff8ed3f778 (rcu_state.exp_mutex){+.+.}-{4:4} , at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] , at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 5 locks held by syz-executor/10171: #0: ffff888030934d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888030934d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2678 #1: ffff888030934078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x60f/0x1260 net/bluetooth/hci_sync.c:5213 #2: ffffffff9024b808 ( hci_cb_list_lock ){+.+.}-{4:4} , at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2066 [inline] , at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2701 #3: ffff888079a6e338 ( &conn->lock #2 ){+.+.}-{4:4} , at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1761 #4: ffffffff8ed3f778 (rcu_state.exp_mutex){+.+.}-{4:4} , at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] , at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998 2 locks held by kbnepd bnep0/12074: #0: ffffffff90273090 ( bnep_session_sem ){++++}-{4:4} , at: bnep_session+0x2e45/0x3050 net/bluetooth/bnep/core.c:522 #1: ffffffff900e5808 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: rtnl_net_dev_lock+0x271/0x320 net/core/dev.c:2093 1 lock held by syz.5.2094/13046: #0: ffffffff902744f0 (hidp_session_sem){++++}-{4:4}, at: hidp_session_find+0x1c/0x110 net/bluetooth/hidp/core.c:1026 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-05884-g2ea396448f26 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 5913 Comm: kworker/0:6 Not tainted 6.14.0-syzkaller-05884-g2ea396448f26 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events hidp_session_dev_work RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:409 Code: e0 47 35 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 71 7d 9d fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c RSP: 0018:ffffc900041ceaf8 EFLAGS: 00000002 RAX: 1ffffffff3545b00 RBX: ffffffff9aa2df20 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff858e2f76 R09: 1ffff11004a4d046 R10: dffffc0000000000 R11: ffffffff858e2f30 R12: 0000000000000020 R13: 1ffffffff3545c36 R14: 00000000000003fd R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888124fea000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f09108d7d60 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 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+0x1b1/0x320 drivers/tty/serial/8250/8250_port.c:2098 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3355 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] serial8250_console_write+0x1350/0x1e00 drivers/tty/serial/8250/8250_port.c:3463 console_emit_next_record kernel/printk/printk.c:3120 [inline] console_flush_all+0x86b/0xec0 kernel/printk/printk.c:3208 __console_flush_and_unlock kernel/printk/printk.c:3267 [inline] console_unlock+0x151/0x3b0 kernel/printk/printk.c:3307 vprintk_emit+0x732/0xa10 kernel/printk/printk.c:2432 dev_vprintk_emit+0x358/0x420 drivers/base/core.c:4891 dev_printk_emit+0xdf/0x130 drivers/base/core.c:4902 _dev_warn+0x12d/0x180 drivers/base/core.c:4958 hid_parser_main+0x896/0xc40 drivers/hid/hid-core.c:-1 hid_open_report+0xbda/0x1590 drivers/hid/hid-core.c:1328 hid_parse include/linux/hid.h:1126 [inline] mt_probe+0x522/0xbd0 drivers/hid/hid-multitouch.c:1822 __hid_device_probe drivers/hid/hid-core.c:2717 [inline] hid_device_probe+0x3bf/0x710 drivers/hid/hid-core.c:2754 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2b9/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x258/0x2e0 drivers/base/bus.c:462 __device_attach+0x341/0x530 drivers/base/dd.c:1030 bus_probe_device+0x189/0x260 drivers/base/bus.c:537 device_add+0x856/0xbf0 drivers/base/core.c:3666 hid_add_device+0x3b6/0x520 drivers/hid/hid-core.c:2900 hidp_session_dev_add net/bluetooth/hidp/core.c:856 [inline] hidp_session_dev_work+0x46/0x160 net/bluetooth/hidp/core.c:895 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245