INFO: task udevd:5961 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23000 pid:5961 tgid:5961 ppid:5211 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 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+0x724/0xe80 kernel/locking/mutex.c:746 device_lock include/linux/device.h:922 [inline] uevent_show+0x174/0x330 drivers/base/core.c:2730 dev_attr_show+0x55/0xc0 drivers/base/core.c:2424 sysfs_kf_seq_show+0x30d/0x490 fs/sysfs/file.c:65 seq_read_iter+0x4e7/0xe10 fs/seq_file.c:230 new_sync_read fs/read_write.c:489 [inline] vfs_read+0x4cd/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:713 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff2ee116b6a RSP: 002b:00007ffc3e0e9e78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000560ad6166600 RCX: 00007ff2ee116b6a RDX: 0000000000001000 RSI: 0000560ad615f980 RDI: 0000000000000008 RBP: 0000560ad6166600 R08: 0000000000000008 R09: 0000000000000200 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc3e0ea358 R15: 000000000000000a Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by kworker/u8:4/63: 4 locks held by kworker/u8:6/1145: #0: ffff88801b2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90003dbfc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003dbfc60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f4eacd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8e141338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #3: ffffffff8e141338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 3 locks held by kworker/0:2/5172: 2 locks held by getty/5598: #0: ffff88803008b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by udevd/5851: #0: ffff8880331d5790 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 #1: ffff888030ff3488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154 #2: ffff8880243f9b48 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155 #3: ffff88805b202198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805b202198 (&dev->mutex){....}-{4:4}, at: uevent_show+0x174/0x330 drivers/base/core.c:2730 5 locks held by kworker/1:3/5892: 5 locks held by kworker/0:4/5893: #0: ffff888020ad9548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888020ad9548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000443fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000443fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffff8881457fb198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #2: ffff8881457fb198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5859 #3: ffff88805b202198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88805b202198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1005 #4: ffff88805af82160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff88805af82160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1005 4 locks held by udevd/5961: #0: ffff8880599a6b08 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:182 #1: ffff888031990888 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x55/0x3c0 fs/kernfs/file.c:154 #2: ffff88802914dc38 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x75/0x3c0 fs/kernfs/file.c:155 #3: ffff88801dac2160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #3: ffff88801dac2160 (&dev->mutex){....}-{4:4}, at: uevent_show+0x174/0x330 drivers/base/core.c:2730 2 locks held by kworker/u8:8/6018: #0: ffff888140521148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888140521148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90004987c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004987c60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 1 lock held by syz.2.1832/12373: #0: ffffffff8e141200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3774 1 lock held by syz.4.1838/12389: #0: ffff88807bd1ee08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #0: ffff88807bd1ee08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline] #0: ffff88807bd1ee08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/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+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5892 Comm: kworker/1:3 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:hlock_class kernel/locking/lockdep.c:245 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4880 [inline] RIP: 0010:__lock_acquire+0x4ec/0xd20 kernel/locking/lockdep.c:5185 Code: c6 28 41 89 c4 48 39 cb 0f 8d db 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 06 25 ff 1f 00 00 48 0f a3 05 f6 42 01 12 73 10 <48> 69 c0 c8 00 00 00 48 8d 88 e0 66 40 93 eb 40 83 3d 0d d2 04 18 RSP: 0018:ffffc9000442e5f8 EFLAGS: 00000007 RAX: 00000000000003ff RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88805c599e00 RBP: ffff88805c59a8f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8171a9f5 R12: ffffffffffffff05 R13: 0000000000000000 R14: ffff88805c59a910 R15: ffff88805c59a9b8 FS: 0000000000000000(0000) GS:ffff888125da3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f45d6b7ed38 CR3: 000000007c302000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2398 [inline] slab_free mm/slub.c:4656 [inline] kfree+0x193/0x440 mm/slub.c:4855 ath6kl_usb_post_recv_transfers+0x3ea/0x6f0 drivers/net/wireless/ath/ath6kl/usb.c:460 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+0x6a/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+0x1d6/0x10f0 drivers/net/wireless/ath/ath6kl/core.c:97 ath6kl_usb_probe+0x14df/0x15d0 drivers/net/wireless/ath/ath6kl/usb.c:1168 usb_probe_interface+0x641/0xbc0 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26a/0x9a0 drivers/base/dd.c:658 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:800 driver_probe_device+0x4f/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1030 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3666 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250 usb_probe_device+0x1c1/0x390 drivers/usb/core/driver.c:291 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x26a/0x9a0 drivers/base/dd.c:658 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:800 driver_probe_device+0x4f/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462 __device_attach+0x2b8/0x400 drivers/base/dd.c:1030 bus_probe_device+0x185/0x260 drivers/base/bus.c:537 device_add+0x7b6/0xb50 drivers/base/core.c:3666 usb_new_device+0xa39/0x16c0 drivers/usb/core/hub.c:2663 hub_port_connect drivers/usb/core/hub.c:5531 [inline] hub_port_connect_change drivers/usb/core/hub.c:5671 [inline] port_event drivers/usb/core/hub.c:5831 [inline] hub_event+0x2941/0x4a00 drivers/usb/core/hub.c:5913 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 vkms_vblank_simulate: vblank timer overrun