INFO: task udevd:5840 blocked for more than 143 seconds. Not tainted 6.12.0-rc7-syzkaller-00189-ge8bdb3c8be08 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24224 pid:5840 tgid:5840 ppid:5200 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0xe55/0x5740 kernel/sched/core.c:6693 __schedule_loop kernel/sched/core.c:6770 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6785 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752 device_lock include/linux/device.h:1014 [inline] uevent_show+0x188/0x3b0 drivers/base/core.c:2736 dev_attr_show+0x53/0xe0 drivers/base/core.c:2430 sysfs_kf_seq_show+0x23e/0x410 fs/sysfs/file.c:59 seq_read_iter+0x4f4/0x12b0 fs/seq_file.c:230 kernfs_fop_read_iter+0x414/0x580 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:488 [inline] vfs_read+0x87f/0xbe0 fs/read_write.c:569 ksys_read+0x12f/0x260 fs/read_write.c:712 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4405716b6a RSP: 002b:00007fffb1820538 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000555a7aeef750 RCX: 00007f4405716b6a RDX: 0000000000001000 RSI: 0000555a7af0db50 RDI: 0000000000000008 RBP: 0000555a7aeef750 R08: 0000000000000008 R09: 0000000000000008 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007fffb1820a18 R15: 000000000000000a Showing all locks held in the system: 6 locks held by kworker/0:0/8: #0: ffff8880236e5148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc900000d7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5849 #3: ffff888022b08190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888022b08190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #4: ffff8880655b5160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff8880655b5160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x7f/0x4b0 drivers/base/dd.c:1005 #5: ffffffff8e06e990 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xaa/0x250 kernel/umh.c:215 1 lock held by khungtaskd/30: #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1b8340 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6720 6 locks held by kworker/1:1/51: #0: ffff8880236e5148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90000bc7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff8881453cc190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff8881453cc190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5849 #3: ffff8881453cf510 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff8881453cf510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] #3: ffff8881453cf510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #3: ffff8881453cf510 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #3: ffff8881453cf510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x27ec/0x4e10 drivers/usb/core/hub.c:5903 #4: ffff8881453ee368 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] #4: ffff8881453ee368 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #4: ffff8881453ee368 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #4: ffff8881453ee368 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x2815/0x4e10 drivers/usb/core/hub.c:5903 #5: ffffffff8f4c3990 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x1a5/0x1cd0 drivers/usb/core/hub.c:3021 2 locks held by getty/5586: #0: ffff88814db360a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 4 locks held by udevd/5840: #0: ffff88805c783418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xd8/0x12b0 fs/seq_file.c:182 #1: ffff88803453c488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x4d/0x240 fs/kernfs/file.c:154 #2: ffff88802558d788 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x71/0x240 fs/kernfs/file.c:155 #3: ffff888022b08190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff888022b08190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x188/0x3b0 drivers/base/core.c:2736 3 locks held by kworker/0:5/5873: #0: ffff88801b078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90003d2fd80 (xfrm_state_gc_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff8e1c3c38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:329 2 locks held by kworker/u8:14/5973: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90004407d80 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 2 locks held by kworker/u8:15/5977: 3 locks held by kworker/u8:19/5991: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc90004247d80 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffffffff8e1c3c38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:297 1 lock held by syz.2.1276/11706: #0: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #0: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x1b8/0x8c0 drivers/usb/core/devio.c:1051 1 lock held by syz.0.1346/11998: #0: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #0: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x1b8/0x8c0 drivers/usb/core/devio.c:1051 1 lock held by syz.1.1361/12072: #0: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #0: ffff888028bfc190 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x1b8/0x8c0 drivers/usb/core/devio.c:1051 6 locks held by kworker/0:3/12384: #0: ffff8880236e5148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x129b/0x1ba0 kernel/workqueue.c:3204 #1: ffffc9001f5d7d80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205 #2: ffff888028d5c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff888028d5c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4e10 drivers/usb/core/hub.c:5849 #3: ffff888028d5f510 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff888028d5f510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] #3: ffff888028d5f510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #3: ffff888028d5f510 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #3: ffff888028d5f510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x27ec/0x4e10 drivers/usb/core/hub.c:5903 #4: ffff8880284fd068 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] #4: ffff8880284fd068 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #4: ffff8880284fd068 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #4: ffff8880284fd068 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x2815/0x4e10 drivers/usb/core/hub.c:5903 #5: ffffffff8f4c3990 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x1a5/0x1cd0 drivers/usb/core/hub.c:3021 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc7-syzkaller-00189-ge8bdb3c8be08 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __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:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xf0c/0x1240 kernel/hung_task.c:379 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5977 Comm: kworker/u8:15 Not tainted 6.12.0-rc7-syzkaller-00189-ge8bdb3c8be08 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:debug_lockdep_rcu_enabled+0x26/0x40 kernel/rcu/update.c:320 Code: 90 90 90 90 f3 0f 1e fa 8b 05 6a b7 3b 05 85 c0 74 20 8b 05 94 e9 3b 05 85 c0 74 16 65 48 8b 05 f0 34 e0 74 8b 80 dc 0a 00 00 <85> c0 0f 94 c0 0f b6 c0 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ffffc90004437488 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff88801ed34c00 RCX: ffffffff81fb4c60 RDX: ffff888024fd8000 RSI: ffffffff81fb1f87 RDI: ffff88801ed34c00 RBP: ffff88801ed34c00 R08: 0000000000000006 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffff88801ed34bfc R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0b1ad08ab8 CR3: 000000003303c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:878 [inline] page_ext_put+0x1c/0xd0 mm/page_ext.c:550 __page_table_check_zero+0x2d7/0x360 mm/page_table_check.c:160 page_table_check_alloc include/linux/page_table_check.h:33 [inline] post_alloc_hook+0x2c0/0x350 mm/page_alloc.c:1557 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3474 __alloc_pages_noprof+0x223/0x25a0 mm/page_alloc.c:4750 alloc_pages_mpol_noprof+0x2c9/0x610 mm/mempolicy.c:2265 alloc_slab_page mm/slub.c:2412 [inline] allocate_slab mm/slub.c:2578 [inline] new_slab+0x2c9/0x410 mm/slub.c:2631 ___slab_alloc+0xdac/0x1880 mm/slub.c:3818 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908 __slab_alloc_node mm/slub.c:3961 [inline] slab_alloc_node mm/slub.c:4122 [inline] kmem_cache_alloc_node_noprof+0xed/0x310 mm/slub.c:4186 __alloc_skb+0x2b1/0x380 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1322 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x2a4/0xc90 drivers/net/netdevsim/dev.c:851 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244