INFO: task syz.1.3574:20074 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3574      state:D stack:27512 pid:20074 tgid:20073 ppid:15694  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
 fdget_pos+0x2a2/0x370 fs/file.c:1213
 class_fd_pos_constructor include/linux/file.h:85 [inline]
 do_writev+0x75/0x340 fs/read_write.c:1094
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa13ab8e929
RSP: 002b:00007fa13babb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007fa13adb5fa0 RCX: 00007fa13ab8e929
RDX: 0000000000000001 RSI: 0000200000000000 RDI: 0000000000000009
RBP: 00007fa13ac10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa13adb5fa0 R15: 00007ffd8453e218
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5c4840 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c4840 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e5c4840 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by getty/5572:
 #0: ffff88803262a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
9 locks held by kworker/1:3/5827:
6 locks held by kworker/0:4/5902:
 #0: ffff8881436ef948
 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc9000574fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff888029d50198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
 #2: ffff888029d50198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5863
 #3: ffff888051c58198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
 #3: ffff888051c58198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: ffff88805e59c160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
 #4: ffff88805e59c160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #5: ffff888037449c18 (&dev->ctrl_urb_lock){+.+.}-{4:4}, at: em28xx_read_reg_req_len+0x141/0x3c0 drivers/media/usb/em28xx/em28xx-core.c:79
10 locks held by kworker/0:2/18196:
1 lock held by syz.1.3574/20074:
 #0: ffff88803122aef8 (&f->f_pos_lock){+.+.}-{4:4}
, at: fdget_pos+0x2a2/0x370 fs/file.c:1213
3 locks held by syz.1.3574/20075:
 #0: ffff88803122aef8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2a2/0x370 fs/file.c:1213
 #1: ffff8880290b0428 (sb_writers#21){.+.+}-{0:0}, at: do_writev+0x132/0x340 fs/read_write.c:1103
 #2: 
ffff8880589987b8
 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: netfs_start_io_direct+0x116/0x260 fs/netfs/locking.c:188

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/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+0xf70/0x12c0 kernel/hung_task.c:470
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18196 Comm: kworker/0:2 Not tainted 6.16.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:391 [inline]
RIP: 0010:__rcu_read_lock+0x2a/0xf0 kernel/rcu/tree_plugin.h:414
Code: f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 55 53 65 48 8b 1d 00 78 2b 12 48 8d bb 44 04 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 a6 00 00 00 65
RSP: 0018:ffffc90000007770 EFLAGS: 00000803
RAX: dffffc0000000000 RBX: ffff88802c462440 RCX: ffffc9000000774c
RDX: 0000000000000000 RSI: ffffffff817cec29 RDI: ffff88802c462884
RBP: ffffc90000007840 R08: ffffffff913da7ce R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000007ce5 R12: ffffffff81a780f0
R13: ffffc900000077f8 R14: 0000000000000000 R15: ffff88802c462440
FS:  0000000000000000(0000) GS:ffff888124754000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31407ff8 CR3: 0000000061f80000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock include/linux/rcupdate.h:839 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xae/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2381 [inline]
 slab_free mm/slub.c:4643 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4842
 dummy_timer+0x1799/0x3a20 drivers/usb/gadget/udc/dummy_hcd.c:1989
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x567/0x6d0 kernel/printk/printk.c:2449
Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 e4 98 20 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 42 94 20 00 48 85 ed 0f 85 25 01 00 00 <e8> c4 98 20 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00
RSP: 0018:ffffc9000587ea58 EFLAGS: 00000246
RAX: 0000000000100000 RBX: 0000000000000038 RCX: ffffc9001af9f000
RDX: 0000000000100000 RSI: ffffffff819b8506 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 1ffff92000b0fd4d
R13: 0000000000000200 R14: ffff88801fa92440 R15: ffffc9000587eb20
 dev_vprintk_emit drivers/base/core.c:4917 [inline]
 dev_printk_emit+0xfa/0x140 drivers/base/core.c:4928
 __dev_printk+0xf5/0x270 drivers/base/core.c:4940
 _dev_err+0xe4/0x120 drivers/base/core.c:4983
 mce_write+0x720/0xad0 drivers/media/rc/mceusb.c:847
 mce_command_out drivers/media/rc/mceusb.c:909 [inline]
 mceusb_get_emulator_version drivers/media/rc/mceusb.c:1410 [inline]
 mceusb_dev_probe+0x1924/0x38f0 drivers/media/rc/mceusb.c:1788
 usb_probe_interface+0x303/0x9c0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 usb_set_configuration+0x1187/0x1e20 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x3e0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:579 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x156/0x1e0 drivers/base/bus.c:462
 __device_attach+0x1e4/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:537
 device_add+0x1148/0x1a70 drivers/base/core.c:3692
 usb_new_device+0xd07/0x1a20 drivers/usb/core/hub.c:2663
 hub_port_connect drivers/usb/core/hub.c:5535 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5675 [inline]
 port_event drivers/usb/core/hub.c:5835 [inline]
 hub_event+0x2eb7/0x4fa0 drivers/usb/core/hub.c:5917
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>