INFO: task syz.4.141:6582 blocked for more than 143 seconds. Not tainted 6.15.0-next-20250606-syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.141 state:D stack:25032 pid:6582 tgid:6578 ppid:5838 task_flags:0x40054c flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 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 uhid_dev_destroy drivers/hid/uhid.c:584 [inline] uhid_char_release+0xac/0x600 drivers/hid/uhid.c:662 __fput+0x44c/0xa70 fs/file_table.c:467 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f01c238e929 RSP: 002b:00007f01c01f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: 0000000000000064 RBX: 00007f01c25b5fa0 RCX: 00007f01c238e929 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f01c2410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f01c25b5fa0 R15: 00007fffff58a9d8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5595: #0: ffff8880359920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/5837: 2 locks held by dhcpcd-run-hook/8201: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5837 Comm: kworker/1:3 Not tainted 6.15.0-next-20250606-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events uhid_device_add_worker RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 0e 94 78 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 cf 0b dc fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 da ce 21 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc9000437ebf0 EFLAGS: 00000002 RAX: 1ffffffff33b9a00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99dcd9d0 R08: ffff888024530237 R09: 1ffff110048a6046 R10: dffffc0000000000 R11: ffffffff8547ca80 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99dcd740 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d4d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055afb473e950 CR3: 000000007c584000 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+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:2724 [inline] hid_device_probe+0x39d/0x710 drivers/hid/hid-core.c:2761 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:2907 uhid_device_add_worker+0x43/0xf0 drivers/hid/uhid.c:73 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+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245