INFO: task udevd:5845 blocked for more than 143 seconds. Not tainted 6.15.0-rc2-syzkaller-00258-g750d0ac001e8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25864 pid:5845 tgid:5845 ppid:5213 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 device_lock include/linux/device.h:922 [inline] uevent_show+0x17d/0x340 drivers/base/core.c:2730 dev_attr_show+0x55/0xc0 drivers/base/core.c:2424 sysfs_kf_seq_show+0x32b/0x4a0 fs/sysfs/file.c:65 seq_read_iter+0x461/0xda0 fs/seq_file.c:230 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x9a0/0xb90 fs/read_write.c:570 ksys_read+0x19d/0x2d0 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2bc858db6a RSP: 002b:00007ffc64d12838 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000056124eb31710 RCX: 00007f2bc858db6a RDX: 0000000000001000 RSI: 000056124eb38620 RDI: 0000000000000008 RBP: 000056124eb31710 R08: 0000000000000008 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc64d12d18 R15: 000000000000000a INFO: task khidpd_04570009:5850 blocked for more than 143 seconds. Not tainted 6.15.0-rc2-syzkaller-00258-g750d0ac001e8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:khidpd_04570009 state:D stack:28704 pid:5850 tgid:5850 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0xb1/0x2b0 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+0x32f/0x600 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_session_thread+0x450/0x490 net/bluetooth/hidp/core.c:1304 kthread+0x7b7/0x940 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 INFO: task syz-executor142:5857 blocked for more than 144 seconds. Not tainted 6.15.0-rc2-syzkaller-00258-g750d0ac001e8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor142 state:D stack:27304 pid:5857 tgid:5857 ppid:5843 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 l2cap_chan_connect+0x102/0xea0 net/bluetooth/l2cap_core.c:6955 l2cap_sock_connect+0x622/0x950 net/bluetooth/l2cap_sock.c:256 __sys_connect_file net/socket.c:2038 [inline] __sys_connect+0x28c/0x2d0 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2060 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f54c14870c9 RSP: 002b:00007ffd52291088 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f54c14870c9 RDX: 000000000000000e RSI: 0000200000000080 RDI: 0000000000000004 RBP: 00000000000f4240 R08: 0000000000000000 R09: 0000555500000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd522910d0 R13: 00007ffd522910e0 R14: 0000000000016197 R15: 00007ffd522910a0 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 8 locks held by kworker/0:2/838: 5 locks held by kworker/u8:9/3566: #0: ffff8880b8739b18 (&rq->__lock){-.-.}-{2:2} , at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8723b08 ( &per_cpu_ptr(group->pcpu, cpu)->seq ){-.-.}-{0:0} , at: psi_task_switch+0x41f/0x7a0 kernel/sched/psi.c:987 #2: ffff8880b8725558 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1046 [inline] #2: ffff8880b8725558 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x24c/0x10f0 kernel/time/timer.c:1127 #3: ffffffff9a9fe9e8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x190/0x5c0 lib/debugobjects.c:818 #4: ffffffff8ebea1c8 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145 2 locks held by getty/5600: #0: ffff88803628a0a0 (&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+0x5bb/0x1700 drivers/tty/n_tty.c:2222 4 locks held by udevd/5845: #0: ffff888032e7d2f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xda0 fs/seq_file.c:182 #1: ffff888030608c88 ( &of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff888034cec1e8 ( kn->active #5 ){.+.+}-{0:0} , at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88807eee5a20 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:922 [inline] , at: uevent_show+0x17d/0x340 drivers/base/core.c:2730 2 locks held by khidpd_04570009/5850: #0: ffff888035eac078 (&hdev->lock){+.+.}-{4:4}, at: l2cap_unregister_user+0x6a/0x1c0 net/bluetooth/l2cap_core.c:1727 #1: ffffffff9028c450 (hidp_session_sem ){++++}-{4:4} , at: hidp_session_remove+0x2d/0x260 net/bluetooth/hidp/core.c:1165 1 lock held by syz-executor142/5857: #0: ffff888035eac078 (&hdev->lock){+.+.}-{4:4}, at: l2cap_chan_connect+0x102/0xea0 net/bluetooth/l2cap_core.c:6955 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc2-syzkaller-00258-g750d0ac001e8 #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:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 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: 838 Comm: kworker/0:2 Not tainted 6.15.0-rc2-syzkaller-00258-g750d0ac001e8 #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_out+0x7e/0xc0 drivers/tty/serial/8250/8250_port.c:416 Code: fc 89 e9 41 d3 e7 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 2c 68 96 fc 44 03 3b 44 89 f0 44 89 fa ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c a7 RSP: 0018:ffffc90003746b50 EFLAGS: 00000002 RAX: 000000000000005b RBX: ffffffff9aa7db80 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff8596915b R09: 1ffff110049d2046 R10: dffffc0000000000 R11: ffffffff85969110 R12: dffffc0000000000 R13: 000000000000005b R14: 000000000000005b R15: 00000000000003f8 FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056123f6a6048 CR3: 000000003003a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x1434/0x1e00 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x86b/0xec0 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0x151/0x3b0 kernel/printk/printk.c:3325 vprintk_emit+0x761/0xa40 kernel/printk/printk.c:2450 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+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 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 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.064 msecs