INFO: task syz.1.13968:22911 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.13968 state:D stack:28120 pid:22911 tgid:22908 ppid:7475 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 device_lock include/linux/device.h:1040 [inline] usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411 do_dentry_open+0x785/0x14e0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf2bd5d60e RSP: 002b:00007fcf2cc45b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fcf2cc466c0 RCX: 00007fcf2bd5d60e RDX: 0000000000000002 RSI: 00007fcf2cc45c00 RDI: ffffffffffffff9c RBP: 00007fcf2cc45c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fcf2c016038 R14: 00007fcf2c015fa0 R15: 00007fcf2c13fa48 Showing all locks held in the system: 6 locks held by kworker/0:1/10: 1 lock held by khungtaskd/30: #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by pvrusb2-context/2364: 2 locks held by getty/5380: #0: ffff888035b870a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:2/9454: #0: ffff88801fe8ad40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801fe8ad40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006b47c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006b47c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffff888029fa31d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff888029fa31d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 1 lock held by syz.1.13968/22911: #0: ffff888029e2b1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff888029e2b1d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 1 lock held by syz.0.15381/29481: #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 2364 Comm: pvrusb2-context Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__bfs kernel/locking/lockdep.c:1753 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x1821/0x2cf0 kernel/locking/lockdep.c:5237 Code: 00 0f 83 8a 01 00 00 4e 8b 24 fd 40 58 41 96 ff c0 25 ff 0f 00 00 89 05 4d 0e a0 14 4d 85 e4 0f 84 b2 01 00 00 49 8b 44 24 10 <48> 85 c0 0f 84 1c 0d 00 00 8b 0d 38 0e a0 14 39 48 5c 0f 84 67 ff RSP: 0018:ffffc90006de67a0 EFLAGS: 00000086 RAX: ffffffff93ea6788 RBX: 00000000000003fd RCX: ffffffff96e0b518 RDX: ffffffff93eb5150 RSI: ffff88802c1d8c30 RDI: 00000000000003fd RBP: ac087c584408ab33 R08: ffffc90006de6768 R09: 0000000000000020 R10: 0000000000000003 R11: ffffffff81a21c50 R12: ffffffff96e0b518 R13: ffff88802c1d8c30 R14: ffff88802c1d8000 R15: 000000000000052e FS: 0000000000000000(0000) GS:ffff888125290000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e714ff8 CR3: 00000000379a2000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73 ktime_get+0x45/0x220 kernel/time/timekeeping.c:965 clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363 hrtimer_rearm kernel/time/hrtimer.c:2039 [inline] __hrtimer_rearm_deferred+0x270/0x450 kernel/time/hrtimer.c:2059 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:513 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:550 [inline] irqentry_exit+0x6a0/0x730 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 42 27 21 00 fb eb 44 e8 3a 27 21 00 e8 15 b0 03 0a 4d 85 f6 74 94 e8 2b 27 21 00 fb 48 c7 c7 a0 f1 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18 RSP: 0018:ffffc90006de6be0 EFLAGS: 00000293 RAX: ffffffff81a49515 RBX: ffffffff81a4938f RCX: ffff88802c1d8000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e94f1a0 RBP: ffffc90006de6c90 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe R10: dffffc0000000000 R11: fffffbfff20614ff R12: 0000000000000000 R13: 0000000000000050 R14: 0000000000000200 R15: 1ffff92000dbcd80 _printk+0xdd/0x130 kernel/printk/printk.c:2504 i2c_hack_cx25840+0x4c3/0x660 drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c:335 pvr2_i2c_xfer+0x9e3/0xda0 drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c:445 __i2c_transfer+0x79a/0x1f70 drivers/i2c/i2c-core-base.c:-1 i2c_transfer+0x1cc/0x2d0 drivers/i2c/i2c-core-base.c:2317 cx25840_read drivers/media/i2c/cx25840/cx25840-core.c:118 [inline] cx25840_probe+0x2a9/0x2210 drivers/media/i2c/cx25840/cx25840-core.c:3800 i2c_device_probe+0x894/0xc00 drivers/i2c/i2c-core-base.c:592 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x267/0xaf0 drivers/base/dd.c:709 __driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871 driver_probe_device+0x4f/0x240 drivers/base/dd.c:901 __device_attach_driver+0x279/0x430 drivers/base/dd.c:1029 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500 __device_attach+0x2c5/0x450 drivers/base/dd.c:1101 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156 bus_probe_device+0x12a/0x220 drivers/base/bus.c:613 device_add+0x7e9/0xbb0 drivers/base/core.c:3706 i2c_new_client_device+0xa1f/0x1160 drivers/i2c/i2c-core-base.c:1019 v4l2_i2c_new_subdev_board+0x86/0x250 drivers/media/v4l2-core/v4l2-i2c.c:81 v4l2_i2c_new_subdev+0x167/0x210 drivers/media/v4l2-core/v4l2-i2c.c:136 pvr2_hdw_load_subdev drivers/media/usb/pvrusb2/pvrusb2-hdw.c:-1 [inline] pvr2_hdw_load_modules drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2074 [inline] pvr2_hdw_setup_low drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2155 [inline] pvr2_hdw_setup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2261 [inline] pvr2_hdw_initialize+0xe80/0x3c50 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:111 [inline] pvr2_context_thread_func+0x490/0xb40 drivers/media/usb/pvrusb2/pvrusb2-context.c:158 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245