INFO: task kworker/0:1:15218 blocked for more than 143 seconds. Not tainted 6.1.140-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1 state:D stack:25136 pid:15218 ppid:2 flags:0x00004000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 usb_kill_urb+0x1c2/0x2f0 drivers/usb/core/urb.c:728 usb_start_wait_urb+0x189/0x4b0 drivers/usb/core/message.c:64 usb_internal_control_msg drivers/usb/core/message.c:102 [inline] usb_control_msg+0x22f/0x3e0 drivers/usb/core/message.c:153 get_bMaxPacketSize0 drivers/usb/core/hub.c:4770 [inline] hub_port_init+0xcd3/0x2ac0 drivers/usb/core/hub.c:4967 hub_port_connect drivers/usb/core/hub.c:5418 [inline] hub_port_connect_change drivers/usb/core/hub.c:5629 [inline] port_event drivers/usb/core/hub.c:5785 [inline] hub_event+0x2724/0x5210 drivers/usb/core/hub.c:5867 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92b4b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92bcd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8c92ab20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92ab20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92ab20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by klogd/3613: 2 locks held by getty/4016: #0: ffff88802ff99098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 5 locks held by kworker/0:1/15218: #0: ffff88823bc1c138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003bf7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88814537f190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #2: ffff88814537f190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x5210 drivers/usb/core/hub.c:5813 #3: ffff88814539a4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3172 [inline] #3: ffff88814539a4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5385 [inline] #3: ffff88814539a4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5629 [inline] #3: ffff88814539a4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5785 [inline] #3: ffff88814539a4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2079/0x5210 drivers/usb/core/hub.c:5867 #4: ffff888147765768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5386 [inline] #4: ffff888147765768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5629 [inline] #4: ffff888147765768 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5785 [inline] #4: ffff888147765768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x20a9/0x5210 drivers/usb/core/hub.c:5867 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3613 Comm: klogd Not tainted 6.1.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67 Code: 38 c1 0f 8c c6 fc ff ff 4c 89 e7 e8 ba ce 99 00 48 ba 00 00 00 00 00 fc ff df e9 af fc ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 <48> 8b 07 c3 00 00 cc cc 00 00 cc cc 00 00 cc cc 31 c0 81 ff 03 00 RSP: 0018:ffffc90003297150 EFLAGS: 00000202 RAX: ffffc90003297201 RBX: ffffc90003290000 RCX: 0000000000000001 RDX: ffffc90003297328 RSI: dffffc0000000000 RDI: ffffc900032972d8 RBP: 1ffff92000652e5d R08: ffffc900032972d8 R09: ffffc90003297338 R10: fffff52000652e69 R11: 1ffff92000652e67 R12: 1ffff92000652e5e R13: 1ffff92000652e5f R14: ffffc90003298000 R15: dffffc0000000000 FS: 00007f6eb5791c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ad1aafe168 CR3: 000000007e40e000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: deref_stack_reg+0x19f/0x230 arch/x86/kernel/unwind_orc.c:360 unwind_next_frame+0x1758/0x20b0 arch/x86/kernel/unwind_orc.c:-1 __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:717 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x51/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1a5/0x200 mm/slub.c:2586 put_cpu_partial+0x17c/0x250 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3443 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] alloc_skb_with_frags+0xa7/0x710 net/core/skbuff.c:6162 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2750 unix_dgram_sendmsg+0x57e/0x18d0 net/unix/af_unix.c:1918 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] __sys_sendto+0x44f/0x5c0 net/socket.c:2153 __do_sys_sendto net/socket.c:2165 [inline] __se_sys_sendto net/socket.c:2161 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2161 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6eb58e1407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffd2d3e1a20 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f6eb5791c80 RCX: 00007f6eb58e1407 RDX: 0000000000000072 RSI: 00007ffd2d3e1b60 RDI: 0000000000000003 RBP: 00007ffd2d3e1f90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffd2d3e1fa8 R13: 00007ffd2d3e1b60 R14: 0000000000000057 R15: 00007ffd2d3e1b60