INFO: task syz.7.6629:21329 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.6629      state:D stack:0     pid:21329 tgid:21328 ppid:18487  flags:0x00004004
Call Trace:
 <TASK>
 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
 super_lock+0x150/0x300 fs/super.c:115
 super_lock_shared fs/super.c:140 [inline]
 iterate_supers+0x8a/0x560 fs/super.c:934
 ksys_sync+0x95/0x160 fs/sync.c:103
 __ia32_sys_sync+0x12/0x20 fs/sync.c:114
 x64_sys_call+0x2a58/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:163
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f6b2338ebe9
RSP: 002b:00007f6b2419f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f6b235c5fa0 RCX: 00007f6b2338ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6b235c5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6b235c6038 R14: 00007f6b235c5fa0 R15: 00007ffc16a0ca08
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 7889a62797c5970a6d86d60f5314b8c2dceacd81
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __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+0x2c7/0x370 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 25755 Comm: syz.8.8012 Not tainted syzkaller #0 7889a62797c5970a6d86d60f5314b8c2dceacd81
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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 14 96 c3 fe 45 03 37 89 d8 44 89 f2 ee <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 8c 28 76 02 cc 44 89 e1 80 e1 07
RSP: 0018:ffffc90001d97508 EFLAGS: 00000002
RAX: 0000000000000035 RBX: 0000000000000035 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000008d43 RDI: 0000000000008d44
RBP: ffffc90001d97530 R08: ffff888107e80107 R09: 1ffff11020fd0020
R10: 0000000000000000 R11: ffffffff83188240 R12: 0000000000000000
R13: dffffc0000000000 R14: 00000000000003f8 R15: ffffffff889f1de8
FS:  00007eff8ca7b6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007eff8bef1000 CR3: 0000000116cc6000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 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+0x166a/0x2130 drivers/tty/serial/8250/8250_port.c:3422
 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+0x5e3/0xaa0 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
 vprintk_default+0x2a/0x40 kernel/printk/printk.c:2478
 vprintk+0x93/0xa0 kernel/printk/printk_safe.c:73
 _printk+0xd0/0x120 kernel/printk/printk.c:2488
 usb_gadget_register_driver_owner+0x216/0x270 drivers/usb/gadget/udc/core.c:1710
 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:595 [inline]
 raw_ioctl+0x130e/0x3600 drivers/usb/gadget/legacy/raw_gadget.c:1306
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0x132/0x1b0 fs/ioctl.c:893
 __x64_sys_ioctl+0x7f/0xa0 fs/ioctl.c:893
 x64_sys_call+0x1878/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7eff8bb8e7eb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007eff8ca78f10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007eff8bb8e7eb
RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000005
RBP: 00007eff8ca79fe0 R08: 0000000000000000 R09: 00382e6364755f79
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007eff8ca78fb0 R14: 0000200000000000 R15: 00007eff8bef0b88
 </TASK>