INFO: task udevd:4278 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:udevd state:D stack:27360 pid:4278 ppid:3624 flags:0x00004002 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 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 device_lock include/linux/device.h:837 [inline] uevent_show+0x16c/0x320 drivers/base/core.c:2669 dev_attr_show+0x50/0xb0 drivers/base/core.c:2372 sysfs_kf_seq_show+0x349/0x4b0 fs/sysfs/file.c:59 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x434/0x920 fs/read_write.c:470 ksys_read+0x143/0x240 fs/read_write.c:613 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: 0033:0x7f1eb46a7407 RSP: 002b:00007ffcb8928f00 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f1eb4d85880 RCX: 00007f1eb46a7407 RDX: 0000000000001000 RSI: 0000558a545e09b0 RDI: 0000000000000008 RBP: 00007f1eb47efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f1eb47efea0 R14: 0000000000000000 R15: 0000558a545e73e0 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 5 locks held by kworker/1:1/26: 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 getty/4015: #0: ffff88807dde0098 (&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 4 locks held by udevd/4278: #0: ffff888079c2cd58 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff88801af0a888 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3b0 fs/kernfs/file.c:154 #2: ffff888145e79a00 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x3b0 fs/kernfs/file.c:155 #3: ffff8881437c3190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #3: ffff8881437c3190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 2 locks held by dhcpcd/4293: #0: ffff88801caac130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline] #0: ffff88801caac130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 #1: ffffffff8c9307f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8c9307f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 2 locks held by dhcpcd/4295: #0: ffff88801cab0130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline] #0: ffff88801cab0130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 #1: ffffffff8c9307f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8c9307f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 1 lock held by dhcpcd/4296: #0: ffff88802ab16130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline] #0: ffff88802ab16130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by dhcpcd/4297: #0: ffff8880247d6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline] #0: ffff8880247d6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by dhcpcd/4309: #0: ffff888024ff6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline] #0: ffff888024ff6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 1 lock held by dhcpcd/4310: #0: ffff888024ff4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline] #0: ffff888024ff4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249 ============================================= 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: 26 Comm: kworker/1:1 Not tainted 6.1.140-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:pvclock_clocksource_read+0x46/0x760 arch/x86/kernel/pvclock.c:68 Code: 1c 4c 8d 57 10 4c 8d 5f 03 48 89 fa 48 c1 ea 03 4d 89 de 49 c1 ee 03 49 8d 48 07 4c 89 c0 48 c1 e8 03 48 89 84 24 90 00 00 00 <48> 89 4c 24 50 48 c1 e9 03 48 89 8c 24 88 00 00 00 49 8d 49 03 4c RSP: 0018:ffffc90000a1e480 EFLAGS: 00000a06 RAX: 1ffffffff1ef9a09 RBX: ffffc90000a1e5a0 RCX: ffffffff8f7cd04f RDX: 1ffffffff1ef9a08 RSI: ffffffff8f7cd05c RDI: ffffffff8f7cd040 RBP: ffffc90000a1e608 R08: ffffffff8f7cd048 R09: ffffffff8f7cd058 R10: ffffffff8f7cd050 R11: ffffffff8f7cd043 R12: 000000000000001a R13: dffffc0000000000 R14: 1ffffffff1ef9a08 R15: ffff88801c209988 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb52374ec40 CR3: 000000007874a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvm_clock_read arch/x86/kernel/kvmclock.c:79 [inline] kvm_sched_clock_read+0x14/0x40 arch/x86/kernel/kvmclock.c:91 sched_clock_cpu+0x6e/0x250 kernel/sched/clock.c:369 local_clock include/linux/sched/clock.h:84 [inline] __set_page_owner_handle+0x1a9/0x3c0 mm/page_owner.c:174 __set_page_owner+0x41/0x60 mm/page_owner.c:195 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5606 alloc_slab_page+0x5d/0x160 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x87/0x2c0 mm/slub.c:1992 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x22a/0x7e0 net/core/skbuff.c:515 __netdev_alloc_skb+0x107/0x4d0 net/core/skbuff.c:579 netdev_alloc_skb include/linux/skbuff.h:3206 [inline] dev_alloc_skb include/linux/skbuff.h:3219 [inline] ath6kl_usb_post_recv_transfers+0x207/0x6f0 drivers/net/wireless/ath/ath6kl/usb.c:428 ath6kl_usb_start_recv_pipes drivers/net/wireless/ath/ath6kl/usb.c:498 [inline] hif_start drivers/net/wireless/ath/ath6kl/usb.c:703 [inline] ath6kl_usb_power_on+0x66/0x280 drivers/net/wireless/ath/ath6kl/usb.c:1062 ath6kl_hif_power_on drivers/net/wireless/ath/ath6kl/hif-ops.h:136 [inline] ath6kl_core_init+0x1ce/0x10c0 drivers/net/wireless/ath/ath6kl/core.c:97 ath6kl_usb_probe+0x144a/0x1540 drivers/net/wireless/ath/ath6kl/usb.c:1168 usb_probe_interface+0x5a0/0xaf0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x175/0x200 drivers/base/bus.c:429 __device_attach+0x29b/0x460 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 usb_new_device+0xd4d/0x1620 drivers/usb/core/hub.c:2631 hub_port_connect drivers/usb/core/hub.c:5489 [inline] hub_port_connect_change drivers/usb/core/hub.c:5629 [inline] port_event drivers/usb/core/hub.c:5785 [inline] hub_event+0x2b02/0x5210 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 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 2.823 msecs