INFO: task udevd:5201 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00110-gf04dd30f1bef #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23576 pid:5201 tgid:5201 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 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+0x724/0xe80 kernel/locking/mutex.c:746 device_lock include/linux/device.h:922 [inline] uevent_show+0x174/0x330 drivers/base/core.c:2730 dev_attr_show+0x55/0xc0 drivers/base/core.c:2424 sysfs_kf_seq_show+0x30d/0x490 fs/sysfs/file.c:65 seq_read_iter+0x4e7/0xe10 fs/seq_file.c:230 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b7fb16b6a RSP: 002b:00007ffc6dbd7d28 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00005641bb063760 RCX: 00007f1b7fb16b6a RDX: 0000000000001000 RSI: 00005641bb05c700 RDI: 000000000000000c RBP: 00005641bb063760 R08: 000000000000000c R09: 0000000000000020 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc6dbd8208 R15: 000000000000000a Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 4 locks held by kworker/u8:7/2891: #0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000bd67c60 ( net_cleanup_work ){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] ){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2e6290 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8f2f2dc8 (rtnl_mutex){+.+.}-{4:4}, at: tc_action_net_exit include/net/act_api.h:173 [inline] #3: ffffffff8f2f2dc8 (rtnl_mutex){+.+.}-{4:4}, at: gate_exit_net+0x30/0x110 net/sched/act_gate.c:653 3 locks held by kworker/u8:9/3023: #0: ffff88801a089148 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3213 [inline] , at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000bf87c60 ( (linkwatch_work).work ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3214 [inline] , at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2f2dc8 ( rtnl_mutex ){+.+.}-{4:4} , at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by udevd/5201: #0: ffff88802db5f540 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 #1: ffff88806e8f7088 (&of->mutex #2 ){+.+.}-{4:4} , at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154 #2: ffff888029652f08 ( kn->active #5 ){.+.+}-{0:0} , at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155 #3: ffff88803183da20 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] ffff88803183da20 (&dev->mutex){....}-{4:4}, at: uevent_show+0x174/0x330 drivers/base/core.c:2730 2 locks held by getty/5584: #0: ffff8880340a00a0 ( &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 8 locks held by kworker/0:3/5842: 3 locks held by syz-executor/11872: #0: ffffffff8ea8db60 ( &ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] &ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] &ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2f2dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] ffffffff8f2f2dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] ffffffff8f2f2dc8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064 #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00110-gf04dd30f1bef #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 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:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 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: 5842 Comm: kworker/0:3 Not tainted 6.15.0-rc3-syzkaller-00110-gf04dd30f1bef #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: events hidp_session_dev_work RIP: 0010:delay_tsc+0x5b/0xc0 arch/x86/lib/delay.c:79 Code: 90 49 89 d7 49 c1 e7 20 49 09 c7 4d 29 f7 49 39 df 73 53 bf 01 00 00 00 e8 92 95 3c f6 65 8b 05 9b e7 20 07 85 c0 74 1c f3 90 01 00 00 00 e8 cb 93 3c f6 e8 e6 38 01 00 39 c5 75 0e 0f 01 f9 RSP: 0018:ffffc900040fec90 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000899 RCX: 0000000000000000 RDX: 0000000000000088 RSI: ffffffff8bc1c800 RDI: 00000000ffffffff RBP: 0000000000000000 R08: ffff888024130237 R09: 1ffff11004826046 R10: dffffc0000000000 R11: ffffffff8b542840 R12: 1ffffffff33691ca R13: 00000000ffffffff R14: 00000088a986e6e9 R15: 00000000000000e7 FS: 0000000000000000(0000) GS:ffff8881260cf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007faba2180178 CR3: 0000000031508000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x160/0x2f0 drivers/tty/serial/8250/8250_port.c:2104 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:4891 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4902 _dev_warn+0x10a/0x160 drivers/base/core.c:4958 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:1126 [inline] hid_generic_probe+0x3d/0x90 drivers/hid/hid-generic.c:66 __hid_device_probe drivers/hid/hid-core.c:2717 [inline] hid_device_probe+0x397/0x710 drivers/hid/hid-core.c:2754 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26a/0x9a0 drivers/base/dd.c:658 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:800 driver_probe_device+0x4f/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1030 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3666 hid_add_device+0x398/0x540 drivers/hid/hid-core.c:2900 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+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 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