INFO: task udevd:5296 blocked for more than 143 seconds. Not tainted 6.11.0-rc2-syzkaller-00257-g5189dafa4cf9 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25088 pid:5296 tgid:5296 ppid:4680 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __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: 0033:0x7ff0dc316b6a RSP: 002b:00007ffde9f0aec8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055d2b5381190 RCX: 00007ff0dc316b6a RDX: 0000000000001000 RSI: 000055d2b5386070 RDI: 0000000000000008 RBP: 000055d2b5381190 R08: 0000000000000008 R09: 0000000000000020 R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffde9f0b3a8 R15: 000000000000000a Showing all locks held in the system: 5 locks held by kworker/0:1/9: #0: ffff88801d69ad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801d69ad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff888023d2c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff888023d2c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849 #3: ffff888021834190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888021834190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1004 #4: ffff88807e814160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff88807e814160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1004 1 lock held by khungtaskd/30: #0: ffffffff8e9382a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e9382a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e9382a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 2 locks held by getty/4982: #0: ffff88802fc580a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5212: #0: ffff8880b923ea18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:568 6 locks held by kworker/1:5/5279: #0: ffff88801d69ad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff88801d69ad48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc9000362fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #1: ffffc9000362fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffff888023d44190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #2: ffff888023d44190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849 #3: ffff88802e560190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88802e560190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1004 #4: ffff88807d705160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #4: ffff88807d705160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x8e/0x520 drivers/base/dd.c:1004 #5: ffffffff8e7e17d0 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0x140/0x300 kernel/umh.c:215 6 locks held by kworker/0:5/5285: 4 locks held by udevd/5296: #0: ffff888027b00e80 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff88802e608c88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff88802ad28008 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff88802e560190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff88802e560190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743 4 locks held by udevd/5641: #0: ffff8880692b98b8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff88805f4f6088 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff88805b5a9b48 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff888021830190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888021830190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743 4 locks held by udevd/7539: #0: ffff888012191790 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb7/0xd60 fs/seq_file.c:182 #1: ffff88802331c488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154 #2: ffff88802abe0d28 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155 #3: ffff888021834190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1009 [inline] #3: ffff888021834190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2743 1 lock held by syz.3.537/8192: 1 lock held by syz.1.542/8200: #0: ffffffff8e93d678 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #0: ffffffff8e93d678 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:958 1 lock held by syz.1.542/8201: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc2-syzkaller-00257-g5189dafa4cf9 #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+0x241/0x360 lib/dump_stack.c:119 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+0xfee/0x1030 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111