INFO: task syz.4.16:520 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.16 state:D stack:0 pid:520 tgid:520 ppid:476 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 __flush_work+0x6d2/0xac0 kernel/workqueue.c:4233 __cancel_work_sync kernel/workqueue.c:4354 [inline] cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4391 uhid_dev_destroy drivers/hid/uhid.c:584 [inline] uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f0580b8e929 RSP: 002b:00007ffef31d47f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000000c5f9 RCX: 00007f0580b8e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f0580db7ba0 R08: 0000000000000001 R09: 00000003f31d4aef R10: 00007f0580a00000 R11: 0000000000000246 R12: 00007f0580db5fac R13: 00007f0580db5fa0 R14: ffffffffffffffff R15: 00007ffef31d4910 INFO: task syz.2.21:524 blocked for more than 124 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.21 state:D stack:0 pid:524 tgid:524 ppid:480 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 __flush_work+0x6d2/0xac0 kernel/workqueue.c:4233 __cancel_work_sync kernel/workqueue.c:4354 [inline] cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4391 uhid_dev_destroy drivers/hid/uhid.c:584 [inline] uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f10f538e929 RSP: 002b:00007fffea05b868 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000000c634 RCX: 00007f10f538e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f10f55b7ba0 R08: 0000000000000001 R09: 00000003ea05bb5f R10: 00007f10f5200000 R11: 0000000000000246 R12: 00007f10f55b5fac R13: 00007f10f55b5fa0 R14: ffffffffffffffff R15: 00007fffea05b980 INFO: task syz.3.22:528 blocked for more than 125 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.22 state:D stack:0 pid:528 tgid:528 ppid:481 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 __flush_work+0x6d2/0xac0 kernel/workqueue.c:4233 __cancel_work_sync kernel/workqueue.c:4354 [inline] cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4391 uhid_dev_destroy drivers/hid/uhid.c:584 [inline] uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f157758e929 RSP: 002b:00007ffe894c5658 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000000c664 RCX: 00007f157758e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f15777b7ba0 R08: 0000000000000001 R09: 00000003894c594f R10: 00007f1577400000 R11: 0000000000000246 R12: 00007f15777b5fac R13: 00007f15777b5fa0 R14: ffffffffffffffff R15: 00007ffe894c5770 INFO: task syz.1.23:533 blocked for more than 126 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.23 state:D stack:0 pid:533 tgid:533 ppid:478 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 __flush_work+0x6d2/0xac0 kernel/workqueue.c:4233 __cancel_work_sync kernel/workqueue.c:4354 [inline] cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4391 uhid_dev_destroy drivers/hid/uhid.c:584 [inline] uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662 __fput+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f9fa338e929 RSP: 002b:00007ffe44fc6c08 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000000c691 RCX: 00007f9fa338e929 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f9fa35b7ba0 R08: 0000000000000001 R09: 0000000344fc6eff R10: 00007f9fa3200000 R11: 0000000000000246 R12: 00007f9fa35b5fac R13: 00007f9fa35b5fa0 R14: ffffffffffffffff R15: 00007ffe44fc6d20 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 95167fa7b47a7fb5a2b4cf844ce00148e80797b6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2ca/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 380 Comm: kworker/1:3 Not tainted syzkaller #0 95167fa7b47a7fb5a2b4cf844ce00148e80797b6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events uhid_device_add_worker RIP: 0010:io_serial_out+0x85/0xd0 drivers/tty/serial/8250/8250_port.c:413 Code: fe 44 89 e1 41 d3 e6 49 83 c7 08 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 d4 78 c3 fe 45 03 37 89 d8 44 89 f2 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 e1 80 e1 07 RSP: 0018:ffffc900010aede8 EFLAGS: 00000002 RAX: 000000000000005b RBX: 000000000000005b RCX: 0000000000000000 RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc900010aee10 R08: ffff888107e8c107 R09: 1ffff11020fd1820 R10: 0000000000000000 R11: ffffffff8318d4e0 R12: 0000000000000000 R13: dffffc0000000000 R14: 00000000000003f8 R15: ffffffff889f3e28 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555619764a8 CR3: 000000010b722000 CR4: 00000000003526b0 Call Trace: serial_out drivers/tty/serial/8250/8250.h:142 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline] serial8250_console_write+0x166d/0x2130 drivers/tty/serial/8250/8250_port.c:3421 univ8250_console_write+0x6f/0xb0 drivers/tty/serial/8250/8250_core.c:396 console_emit_next_record kernel/printk/printk.c:3152 [inline] console_flush_all+0x5e6/0xaa0 kernel/printk/printk.c:3240 __console_flush_and_unlock kernel/printk/printk.c:3299 [inline] console_unlock+0xe9/0x270 kernel/printk/printk.c:3339 vprintk_emit+0x27c/0x640 kernel/printk/printk.c:2463 dev_vprintk_emit+0x33b/0x400 drivers/base/core.c:4962 dev_printk_emit+0xe1/0x130 drivers/base/core.c:4973 __dev_printk+0x17f/0x1b0 drivers/base/core.c:4985 _dev_warn+0x10b/0x160 drivers/base/core.c:5029 hid_parser_main+0x84b/0xdc0 drivers/hid/hid-core.c:632 hid_open_report+0x868/0x1110 drivers/hid/hid-core.c:1278 hid_parse include/linux/hid.h:1138 [inline] hid_generic_probe+0x42/0x90 drivers/hid/hid-generic.c:66 __hid_device_probe drivers/hid/hid-core.c:2711 [inline] hid_device_probe+0x2c1/0x5d0 drivers/hid/hid-core.c:2748 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2d6/0x890 drivers/base/dd.c:657 __driver_probe_device+0x198/0x280 drivers/base/dd.c:799 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957 bus_for_each_drv+0x260/0x2f0 drivers/base/bus.c:459 __device_attach+0x2bd/0x3a0 drivers/base/dd.c:1029 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534 device_add+0x80c/0xc00 drivers/base/core.c:3692 hid_add_device+0x39b/0x560 drivers/hid/hid-core.c:2894 uhid_device_add_worker+0x49/0xf0 drivers/hid/uhid.c:73 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0x7d2/0x1020 kernel/workqueue.c:3319 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400 kthread+0x2ca/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244