INFO: task kworker/1:4:5856 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:4     state:D stack:24152 pid:5856  tgid:5856  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
 __mutex_lock_common kernel/locking/mutex.c:678 [inline]
 __mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:746
 hub_port_connect drivers/usb/core/hub.c:5429 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 port_event drivers/usb/core/hub.c:5831 [inline]
 hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5913
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6764
2 locks held by getty/5563:
 #0: ffff88814dcde0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
5 locks held by kworker/1:4/5856:
 #0: ffff8881446ce148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc9000439fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff88802a16e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #2: ffff88802a16e198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859
 #3: ffff88802a231510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline]
 #3: ffff88802a231510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5428 [inline]
 #3: ffff88802a231510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 #3: ffff88802a231510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline]
 #3: ffff88802a231510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2906/0x4fa0 drivers/usb/core/hub.c:5913
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5429 [inline]
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline]
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5913
5 locks held by kworker/0:4/5859:
 #0: ffff8881446ce148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90002e07d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff8881453aa198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline]
 #2: ffff8881453aa198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859
 #3: ffff8881453ad510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline]
 #3: ffff8881453ad510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5428 [inline]
 #3: ffff8881453ad510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 #3: ffff8881453ad510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline]
 #3: ffff8881453ad510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2906/0x4fa0 drivers/usb/core/hub.c:5913
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5429 [inline]
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5671 [inline]
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5831 [inline]
 #4: ffff88802a0d2c68 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x292b/0x4fa0 drivers/usb/core/hub.c:5913
2 locks held by kworker/u8:9/5974:
4 locks held by syz.4.1546/11336:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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:274 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:437
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11336 Comm: syz.4.1546 Not tainted 6.15.0-rc4-syzkaller-00256-g95d3481af6dc #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x4b/0xc0 kernel/rcu/tree.c:736
Code: 00 00 00 48 8d 3c ed 00 cd ce 8d 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed 00 cd ce 8d <48> b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48
RSP: 0018:ffffc9001aee6e70 EFLAGS: 00000287
RAX: dffffc0000000000 RBX: ffff8880b8532de8 RCX: ffffffff8b6af9cf
RDX: 1ffffffff1b9d9a1 RSI: ffffffff8bf48260 RDI: ffffffff8dcecd08
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000016
R13: ffff888072a9db80 R14: 0000000000000000 R15: 0000000000000001
FS:  00007fa575cc76c0(0000) GS:ffff888124ae1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8e8957fab8 CR3: 000000002ccbf000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_lock_held_common kernel/rcu/update.c:109 [inline]
 rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349
 xa_entry include/linux/xarray.h:1220 [inline]
 xas_descend lib/xarray.c:208 [inline]
 xas_load+0x3a2/0x5b0 lib/xarray.c:246
 filemap_get_entry+0x109/0x3b0 mm/filemap.c:1859
 shmem_get_folio_gfp+0x36b/0x1530 mm/shmem.c:2457
 shmem_get_folio mm/shmem.c:2639 [inline]
 shmem_write_begin+0x160/0x300 mm/shmem.c:3289
 generic_perform_write+0x3cd/0x930 mm/filemap.c:4103
 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3464
 __kernel_write_iter+0x317/0xa90 fs/read_write.c:617
 dump_emit_page fs/coredump.c:885 [inline]
 dump_user_range+0x418/0xb30 fs/coredump.c:959
 elf_core_dump+0x288a/0x3a90 fs/binfmt_elf.c:2128
 do_coredump+0x3183/0x4480 fs/coredump.c:759
 get_signal+0x22e3/0x26d0 kernel/signal.c:3019
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fa574d8e971
Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:00000000fffffe10 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fa574fb5fa0 RCX: 00007fa574d8e969
RDX: 0000000000000000 RSI: 00000000fffffe10 RDI: 0000000000000000
RBP: 00007fa574e10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa574fb5fa0 R15: 00007ffc3f66a358
 </TASK>