INFO: task udevd:8833 blocked for more than 143 seconds. Not tainted 6.11.0-rc1-next-20240729-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24864 pid:8833 tgid:8833 ppid:1 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5239 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6603 __schedule_loop kernel/sched/core.c:6680 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6695 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6752 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 device_lock include/linux/device.h:1009 [inline] uevent_show+0x17d/0x340 drivers/base/core.c:2743 dev_attr_show+0x55/0xc0 drivers/base/core.c:2437 sysfs_kf_seq_show+0x331/0x4c0 fs/sysfs/file.c:59 seq_read_iter+0x445/0xd60 fs/seq_file.c:230 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9bd/0xbc0 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff4cb516b6a RSP: 002b:00007ffc36bda118 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055ea2b6384b0 RCX: 00007ff4cb516b6a RDX: 0000000000001000 RSI: 000055ea2b65b310 RDI: 0000000000000001 RBP: 000055ea2b6384b0 R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffc36bda5f8 R15: 000000000000000a Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e93ce38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93ce38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:967 6 locks held by kworker/1:0/25: 1 lock held by khungtaskd/30: #0: ffffffff8e937a60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e937a60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e937a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6695 3 locks held by kworker/u8:3/52: 8 locks held by kworker/0:2/1170: 2 locks held by getty/4985: #0: ffff88823bcc68a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000312b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211 4 locks held by udevd/5389: #0: ffff88802ef2be80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff88801ead6c88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff8880256550f8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff888062d95190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888062d95190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743 4 locks held by udevd/5395: #0: ffff888022c361c8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff88802cec7088 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff88801f4f9f08 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88805c964190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88805c964190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743 6 locks held by kworker/0:7/8239: 4 locks held by udevd/8833: #0: ffff88802a07bc30 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff88802a8c9488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff888020446a58 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88802d31a190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88802d31a190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743 1 lock held by syz.0.1261/11324: #0: ffffffff8e7f25e8 (sched_core_mutex){+.+.}-{3:3}, at: sched_core_get+0x51/0x180 kernel/sched/core.c:429 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc1-next-20240729-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 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+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1170 Comm: kworker/0:2 Not tainted 6.11.0-rc1-next-20240729-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: usb_hub_wq hub_event RIP: 0010:rb_insert_color+0x652/0x690 lib/rbtree.c:437 Code: 00 00 00 00 fc ff df 48 8b 6c 24 10 48 89 e8 48 c1 e8 03 80 3c 18 00 74 08 48 89 ef e8 67 37 49 f6 4c 89 75 00 48 83 c4 38 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc 4c 8b 7c 24 08 4c 89 f8 RSP: 0018:ffffc9000407e790 EFLAGS: 00000086 RAX: 1ffff1100481a483 RBX: ffff8880b922c901 RCX: dffffc0000000000 RDX: ffffc900149fe000 RSI: ffff8880b922c950 RDI: ffff8880240d2418 RBP: 1ffff11017245a34 R08: ffff8880240d242f R09: 0000000000000000 R10: ffff8880240d2420 R11: ffffed100481a486 R12: ffff8880b922c950 R13: 1ffff11017245a36 R14: ffff8880b922d1a0 R15: ffffc90000be7c41 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffa0afacff0 CR3: 000000002cbaa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rb_insert_color_cached include/linux/rbtree.h:114 [inline] rb_add_cached include/linux/rbtree.h:183 [inline] timerqueue_add+0x260/0x290 lib/timerqueue.c:40 enqueue_hrtimer+0x1b2/0x3c0 kernel/time/hrtimer.c:1093 __hrtimer_start_range_ns kernel/time/hrtimer.c:1260 [inline] hrtimer_start_range_ns+0xac8/0xca0 kernel/time/hrtimer.c:1302 hrtimer_start include/linux/hrtimer.h:275 [inline] dummy_urb_enqueue+0x581/0x760 drivers/usb/gadget/udc/dummy_hcd.c:1307 usb_hcd_submit_urb+0x36c/0x1e80 drivers/usb/core/hcd.c:1533 try_queue_bulk_in+0x425/0x6e0 drivers/char/xillybus/xillyusb.c:741 xillyusb_setup_base_eps drivers/char/xillybus/xillyusb.c:1924 [inline] xillyusb_probe+0x548/0x1240 drivers/char/xillybus/xillyusb.c:2161 usb_probe_interface+0x645/0xbb0 drivers/usb/core/driver.c:399 really_probe+0x2b8/0xad0 drivers/base/dd.c:657 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:799 driver_probe_device+0x50/0x430 drivers/base/dd.c:829 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:957 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:457 __device_attach+0x333/0x520 drivers/base/dd.c:1029 bus_probe_device+0x189/0x260 drivers/base/bus.c:532 device_add+0x856/0xbf0 drivers/base/core.c:3679 usb_set_configuration+0x1976/0x1fb0 drivers/usb/core/message.c:2210 usb_generic_driver_probe+0x88/0x140 drivers/usb/core/generic.c:254 usb_probe_device+0x1b8/0x380 drivers/usb/core/driver.c:294 really_probe+0x2b8/0xad0 drivers/base/dd.c:657 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:799 driver_probe_device+0x50/0x430 drivers/base/dd.c:829 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:957 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:457 __device_attach+0x333/0x520 drivers/base/dd.c:1029 bus_probe_device+0x189/0x260 drivers/base/bus.c:532 device_add+0x856/0xbf0 drivers/base/core.c:3679 usb_new_device+0x104a/0x19a0 drivers/usb/core/hub.c:2651 hub_port_connect drivers/usb/core/hub.c:5521 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x2d6d/0x5150 drivers/usb/core/hub.c:5903 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244