INFO: task udevd:9588 blocked for more than 157 seconds. Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:27232 pid:9588 tgid:9588 ppid:4671 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_hrtimeout_range_clock+0x3c7/0x430 kernel/time/hrtimer.c:2275 ep_poll fs/eventpoll.c:2062 [inline] do_epoll_wait+0x13d4/0x1ae0 fs/eventpoll.c:2464 __do_sys_epoll_wait fs/eventpoll.c:2476 [inline] __se_sys_epoll_wait fs/eventpoll.c:2471 [inline] __x64_sys_epoll_wait+0x194/0x290 fs/eventpoll.c:2471 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: 0033:0x7f7c38f92457 RSP: 002b:00007ffec2bb2798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7c38f92457 RDX: 0000000000000004 RSI: 00007ffec2bb27d8 RDI: 0000000000000004 RBP: 0000556ea9010830 R08: 0000000000000001 R09: 96132b5a1377392b R10: 00000000ffffffff R11: 0000000000000246 R12: 0000556ea90172c0 R13: 00007ffec2bb27d8 R14: 00000000ffffffff R15: 0000556ea8fdb2c0 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8ddb5ca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8ddb5ca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8ddb5ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6620 2 locks held by getty/4970: #0: ffff88802b5710a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:3/5272: 5 locks held by kworker/0:9/6672: #0: ffff8880196e6948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1277/0x1b40 kernel/workqueue.c:3206 #1: ffffc90003dffd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x921/0x1b40 kernel/workqueue.c:3207 #2: ffff888023855190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff888023855190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1c1/0x4e20 drivers/usb/core/hub.c:5849 #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #3: ffff888023888518 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2802/0x4e20 drivers/usb/core/hub.c:5903 #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #4: ffff888023059568 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x282b/0x4e20 drivers/usb/core/hub.c:5903 1 lock held by syz-executor/7037: #0: ffffffff8ddc1438 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 2 locks held by dhcpcd/10497: #0: ffff88804a7d2258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff88804a7d2258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266 #1: ffffffff8ddc1438 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:328 1 lock held by dhcpcd/10498: #0: ffff8880657ba258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880657ba258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266 1 lock held by dhcpcd/10499: #0: ffff8880657bc258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff8880657bc258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266 1 lock held by dhcpcd/10500: #0: ffff88807ca40258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1607 [inline] #0: ffff88807ca40258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3266 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc1-syzkaller-00334-ga5dbd76a8942 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 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+0xf4e/0x1280 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111