INFO: task udevd:4279 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:27208 pid:4279 ppid:3623 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: 0033:0x7f4d8f2a7407 RSP: 002b:00007ffc02a04d70 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f4d8f9e8880 RCX: 00007f4d8f2a7407 RDX: 0000000000001000 RSI: 000055ee31fee9b0 RDI: 0000000000000008 RBP: 00007f4d8f3efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a R13: 00007f4d8f3efea0 R14: 0000000000000000 R15: 000055ee31fefed0 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 5 locks held by kworker/0:2/127: 2 locks held by getty/4011: #0: ffff88814d511098 (&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/4279: #0: ffff88802ad56e80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182 #1: ffff888028a89488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3b0 fs/kernfs/file.c:154 #2: ffff88801a2ab918 (kn->active#5){.+.+}-{0:0}, at: kernfs_seq_start+0x71/0x3b0 fs/kernfs/file.c:155 #3: ffff888143fd2190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #3: ffff888143fd2190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x16c/0x320 drivers/base/core.c:2669 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 127 Comm: kworker/0:2 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:deref_stack_reg+0x1cf/0x230 arch/x86/kernel/unwind_orc.c:362 Code: 24 18 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 b3 d6 99 00 4c 89 33 b0 01 eb 02 31 c0 48 83 c4 20 5b 41 5c 41 5d <41> 5e 41 5f 5d c3 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c b8 fe ff RSP: 0018:ffffc900000072b0 EFLAGS: 00000082 RAX: 1ffff92000000e01 RBX: ffffc900000073a8 RCX: 0000000000000001 RDX: ffffc900000073e8 RSI: dffffc0000000000 RDI: ffffc90002d67268 RBP: 1ffff92000000e75 R08: ffffc90002d67268 R09: ffffc900000073f8 R10: fffff52000000e81 R11: 1ffff92000000e7f R12: ffffffff8ebf106b R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff7c892c30 CR3: 000000007b3b0000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x1758/0x20b0 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674 skb_free_head net/core/skbuff.c:762 [inline] skb_release_data+0x5db/0x7c0 net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] consume_skb+0xa2/0x100 net/core/skbuff.c:1035 ath6kl_usb_cleanup_recv_urb drivers/net/wireless/ath/ath6kl/usb.c:171 [inline] ath6kl_usb_recv_complete+0x1d2/0x4d0 drivers/net/wireless/ath/ath6kl/usb.c:551 __usb_hcd_giveback_urb+0x35f/0x520 drivers/usb/core/hcd.c:1675 dummy_timer+0x888/0x31b0 drivers/usb/gadget/udc/dummy_hcd.c:1994 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x522/0xc80 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1772 handle_softirqs+0x2a1/0x920 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:661 irq_exit_rcu+0x5/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:___slab_alloc+0x106f/0x1220 mm/slub.c:3258 Code: 48 c7 44 24 70 00 00 00 00 9c 8f 44 24 70 f7 44 24 70 00 02 00 00 75 3a f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 78 0f 85 ac 00 00 00 4c 89 f8 48 81 c4 80 00 00 00 5b RSP: 0018:ffffc90002d669d0 EFLAGS: 00000206 RAX: 5400fd04232c9c00 RBX: ffff8880b8e3e810 RCX: 5400fd04232c9c00 RDX: dffffc0000000000 RSI: ffffffff8a6c0000 RDI: ffffffff8abf1260 RBP: 0000000000000202 R08: dffffc0000000000 R09: fffffbfff2117056 R10: fffffbfff2117056 R11: 1ffffffff2117055 R12: ffff8880b8e3e810 R13: ffff8880b8e3e7f0 R14: 0000000000000000 R15: ffff8880637e8000 __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