INFO: task syz.4.4055:21979 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.4.4055 state:D stack:24008 pid:21979 tgid:21973 ppid:16182 task_flags:0x480140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 i2c_del_adapter+0x62d/0x820 drivers/i2c/i2c-core-base.c:1814 dvb_usb_i2c_exit+0x9f/0xf0 drivers/media/usb/dvb-usb/dvb-usb-i2c.c:46 dvb_usb_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:144 [inline] dvb_usb_device_exit+0x313/0x520 drivers/media/usb/dvb-usb/dvb-usb-init.c:338 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:633 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:625 __device_release_driver drivers/base/dd.c:1344 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1367 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657 device_del+0x376/0x9b0 drivers/base/core.c:3880 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1476 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_quiesce+0x16d/0x320 drivers/usb/core/hub.c:1405 hub_disconnect+0xd5/0x510 drivers/usb/core/hub.c:1811 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:633 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:625 __device_release_driver drivers/base/dd.c:1344 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1367 usb_driver_release_interface+0x10e/0x190 drivers/usb/core/driver.c:640 proc_ioctl+0x5cd/0x6f0 drivers/usb/core/devio.c:2359 proc_ioctl_default drivers/usb/core/devio.c:2402 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2766 [inline] usbdev_ioctl+0x1017/0x3aa0 drivers/usb/core/devio.c:2826 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7be99c819 RSP: 002b:00007fd7bf8b8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd7bec16180 RCX: 00007fd7be99c819 RDX: 0000200000000200 RSI: 00000000c0105512 RDI: 0000000000000006 RBP: 00007fd7bea32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7bec16218 R14: 00007fd7bec16180 R15: 00007ffce57cfcb8 INFO: task syz.4.4055:21981 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4055 state:D stack:29000 pid:21981 tgid:21973 ppid:16182 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 device_lock include/linux/device.h:949 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2610 [inline] usbdev_ioctl+0x1a7/0x3aa0 drivers/usb/core/devio.c:2826 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7be99c819 RSP: 002b:00007fd7bf897028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd7bec16270 RCX: 00007fd7be99c819 RDX: 0000200000000040 RSI: 0000000080045505 RDI: 0000000000000006 RBP: 00007fd7bea32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7bec16308 R14: 00007fd7bec16270 R15: 00007ffce57cfcb8 INFO: task syz.4.4055:21986 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.4055 state:D stack:29000 pid:21986 tgid:21973 ppid:16182 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 device_lock include/linux/device.h:949 [inline] usbdev_do_ioctl drivers/usb/core/devio.c:2610 [inline] usbdev_ioctl+0x1a7/0x3aa0 drivers/usb/core/devio.c:2826 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd7be99c819 RSP: 002b:00007fd7bf876028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd7bec16360 RCX: 00007fd7be99c819 RDX: 0000200000000000 RSI: 0000000080045505 RDI: 0000000000000006 RBP: 00007fd7bea32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7bec163f8 R14: 00007fd7bec16360 R15: 00007ffce57cfcb8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:7/1105: #0: ffff8880b843b220 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:655 [inline] #0: ffff8880b843b220 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:639 #1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline] #1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2c11/0x6120 kernel/sched/core.c:6905 #2: ffff8880b8426358 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x6e7/0xca0 kernel/time/timer.c:1117 #3: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #3: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #3: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:764 [inline] #3: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule_buff+0x5c9/0x1520 net/batman-adv/bat_iv_ogm.c:836 #4: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #4: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #4: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline] #4: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x1ea0 arch/x86/kernel/unwind_orc.c:495 2 locks held by getty/5566: #0: ffff8880386f30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:7/16826: #0: ffff8880222ed148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900054dfd08 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88802b0dc1e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #2: ffff88802b0dc1e0 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 1 lock held by udevd/20989: #0: ffff88802782b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 4 locks held by syz.4.4055/21979: #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2610 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x1a7/0x3aa0 drivers/usb/core/devio.c:2826 #1: ffff88802ae0f1a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #1: ffff88802ae0f1a8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline] #1: ffff88802ae0f1a8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1364 #2: ffff88805bbe31e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #2: ffff88805bbe31e0 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2336 #3: ffff88805c7771a8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #3: ffff88805c7771a8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1166 [inline] #3: ffff88805c7771a8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1364 1 lock held by syz.4.4055/21981: #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2610 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x1a7/0x3aa0 drivers/usb/core/devio.c:2826 1 lock held by syz.4.4055/21986: #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2610 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x1a7/0x3aa0 drivers/usb/core/devio.c:2826 1 lock held by syz.9.4173/22433: #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:949 [inline] #0: ffff88802ae341e0 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054 1 lock held by syz.8.4475/23721: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 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: 14110 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:memory_is_nonzero mm/kasan/generic.c:114 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x6e/0x1e0 mm/kasan/generic.c:200 Code: 4c 8d 54 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 <48> 89 da 48 29 ea 48 83 fa 10 0f 8e db 00 00 00 41 89 eb 41 83 e3 RSP: 0018:ffffc90005e379b8 EFLAGS: 00000082 RAX: fffffbfff21b3962 RBX: fffffbfff21b3963 RCX: ffffffff8210fed1 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90d9cb10 RBP: fffffbfff21b3962 R08: 0000000000000000 R09: fffffbfff21b3962 R10: ffffffff90d9cb17 R11: 00ff35e0a80976e5 R12: ffffc90005e37a70 R13: 0000000000000200 R14: 0000000000000006 R15: ffff8880acb8a006 FS: 0000000000000000(0000) GS:ffff88812433b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f56627e92f8 CR3: 000000000e598000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000001 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:82 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:649 [inline] cpu_online include/linux/cpumask.h:1231 [inline] trace_irq_disable include/trace/events/preemptirq.h:36 [inline] trace_hardirqs_off_finish kernel/trace/trace_preemptirq.c:95 [inline] trace_hardirqs_off+0x61/0x190 kernel/trace/trace_preemptirq.c:90 crng_make_state+0x4a7/0x6c0 drivers/char/random.c:361 _get_random_bytes+0x11c/0x220 drivers/char/random.c:399 eth_random_addr include/linux/etherdevice.h:239 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:827 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x3ae/0xd10 drivers/net/netdevsim/dev.c:922 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276 process_scheduled_works kernel/workqueue.c:3359 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245