INFO: task syz.0.791:3175 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.791       state:D stack:0     pid:3175  tgid:3173  ppid:289    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: 0033:0x7f42bb18ebe9
RSP: 002b:00007f42bbfef038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f42bb3b5fa0 RCX: 00007f42bb18ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f42bb3b5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42bb3b6038 R14: 00007f42bb3b5fa0 R15: 00007fffa1586458
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a29bcd2d578c4b9493db917853c72486663e8fa1
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: 10 Comm: kworker/0:1 Not tainted syzkaller #0 a29bcd2d578c4b9493db917853c72486663e8fa1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:__sanitizer_cov_trace_switch+0x104/0x130 kernel/kcov.c:-1
Code: f3 48 c1 e3 05 4c 8d 63 28 4d 39 fc 77 9d 49 ff c6 4d 89 33 49 89 4c 1b 08 4d 89 54 1b 10 49 89 7c 1b 18 49 89 54 1b 20 eb 81 <5b> 41 5c 41 5e 41 5f 5d e9 8f 30 08 04 cc b9 05 00 00 00 48 85 c0
RSP: 0018:ffffc900000a6f30 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 0000000000000029 RCX: 0000000000000005
RDX: ffffffff8169173a RSI: ffffffff873bb3a0 RDI: 0000000000000002
RBP: ffffc900000a6f50 R08: ffff888102655f00 R09: 0000000000000003
R10: 00000000ffffffff R11: 0000000000000002 R12: dffffc0000000000
R13: 00000000fffffedd R14: 0000000000000002 R15: ffffc900000a70e8
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000015140a000 CR4: 00000000003526b0
DR0: 0000000000008009 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1881 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1942 [inline]
 _prb_read_valid+0x61a/0xa90 kernel/printk/printk_ringbuffer.c:2113
 prb_read_valid+0x41/0x80 kernel/printk/printk_ringbuffer.c:2185
 printk_get_next_message+0x168/0x930 kernel/printk/printk.c:3022
 console_emit_next_record kernel/printk/printk.c:3105 [inline]
 console_flush_all+0x3a4/0xaa0 kernel/printk/printk.c:3239
 __console_flush_and_unlock kernel/printk/printk.c:3298 [inline]
 console_unlock+0xe9/0x270 kernel/printk/printk.c:3338
 vprintk_emit+0x27c/0x640 kernel/printk/printk.c:2462
 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_info+0x10b/0x160 drivers/base/core.c:5031
 hub_port_connect drivers/usb/core/hub.c:5572 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5673 [inline]
 port_event drivers/usb/core/hub.c:5837 [inline]
 hub_event+0x2fbe/0x4270 drivers/usb/core/hub.c:5919
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x7d5/0x1020 kernel/workqueue.c:3319
 worker_thread+0xc58/0x1250 kernel/workqueue.c:3400
 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>