INFO: task syz.1.8416:3539 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.8416 state:D stack:24400 pid:3539 ppid:25451 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x107f/0x4030 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x176/0x1050 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x7c4/0x850 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0x9d5/0x2570 kernel/exit.c:881 do_group_exit+0x229/0x2e0 kernel/exit.c:1024 get_signal+0x1259/0x1340 kernel/signal.c:2872 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f147a19ce59 RSP: 002b:00007f147b093028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f147a415fa0 RCX: 00007f147a19ce59 RDX: 0000200000000080 RSI: 00000000000089f1 RDI: 000000000000000e RBP: 00007f147a232e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f147a416038 R14: 00007f147a415fa0 R15: 00007ffdb60dc3f8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2e4f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2ed10 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by kworker/1:2/127: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90002e37d00 (set_printk_work){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: __ftrace_set_clr_event kernel/trace/trace_events.c:1219 [inline] #2: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: trace_set_clr_event+0xbe/0x130 kernel/trace/trace_events.c:1285 1 lock held by udevd/3639: 2 locks held by getty/4030: #0: ffff88807e7e0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198 3 locks held by kworker/u4:6/4328: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc90004507d00 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962 2 locks held by kworker/1:5/29190: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 #1: ffffc9000f91fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267 1 lock held by syz.5.9378/6781: #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 2 locks held by syz.4.9394/6818: #0: ffffffff8dd494e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dd494e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3495 #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962 1 lock held by syz.3.9413/6887: #0: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2a/0x140 kernel/trace/trace_event_perf.c:239 1 lock held by syz.3.9413/6888: #0: ffffffff8dd4ba08 (bpf_dispatcher_xdp.mutex){+.+.}-{3:3}, at: bpf_dispatcher_change_prog+0xc8/0xf10 kernel/bpf/dispatcher.c:146 4 locks held by syz.3.9413/6894: #0: ffffffff8dda97b0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860 #1: ffff88802f6ee698 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: __netlink_dump_start+0x11e/0x6f0 net/netlink/af_netlink.c:2310 #2: ffff88804b81e2f8 (&devlink->lock_key#17){+.+.}-{3:3}, at: devl_lock net/devlink/leftover.c:275 [inline] #2: ffff88804b81e2f8 (&devlink->lock_key#17){+.+.}-{3:3}, at: devlink_nl_cmd_port_get_dumpit+0x16f/0x590 net/devlink/leftover.c:1537 #3: ffffffff8dd494e8 (rtnl_mutex){+.+.}-{3:3}, at: devlink_nl_port_fill+0x2a3/0x950 net/devlink/leftover.c:1276 2 locks held by syz.2.9414/6903: #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 2 locks held by syz.2.9414/6905: #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 2 locks held by syz.2.9414/6910: #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 1 lock held by syz.0.9416/6913: #0: ffffffff8dd4ba08 (bpf_dispatcher_xdp.mutex){+.+.}-{3:3}, at: bpf_dispatcher_change_prog+0xc8/0xf10 kernel/bpf/dispatcher.c:146 2 locks held by syz.0.9416/6914: #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_init_event kernel/events/core.c:11664 [inline] #0: ffffffff96c4a168 (&pmus_srcu){....}-{0:0}, at: perf_event_alloc+0xb28/0x21e0 kernel/events/core.c:11990 #1: ffffffff8cb82c88 (event_mutex){+.+.}-{3:3}, at: perf_trace_init+0x4c/0x2d0 kernel/trace/trace_event_perf.c:221 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf0e/0xf50 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6818 Comm: syz.4.9394 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lock_accessed kernel/locking/lockdep.c:1523 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1747 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1842 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2782 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3094 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3209 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3825 [inline] RIP: 0010:__lock_acquire+0x309c/0x7bd0 kernel/locking/lockdep.c:5049 Code: 5a 1f 6f 00 48 ba 00 00 00 00 00 fc ff df 4d 8b 3f 4d 85 ff 0f 84 7b 28 00 00 49 83 c7 4c 4d 89 fc 49 c1 ec 03 41 0f b6 04 14 <84> c0 0f 85 83 03 00 00 44 8b 2d b5 3e 50 11 45 39 2f 0f 84 a6 fe RSP: 0018:ffffc90005ecf4a0 EFLAGS: 00000807 RAX: 0000000000000000 RBX: 1ffffffff2695735 RCX: 0000000000000008 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff904dcb50 RBP: ffffc90005ecf6d0 R08: ffffc90005ecf657 R09: ffffc90005ecf620 R10: dffffc0000000000 R11: fffff52000bd9ecb R12: 1ffffffff2096521 R13: 00000000000003cc R14: ffffffff934ab998 R15: ffffffff904b290c FS: 000055556bdfb500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3732e8 CR3: 00000000664e3000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000008d24 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x32/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] dev_reset_queue+0x133/0x1a0 include/net/sch_generic.h:681 netdev_for_each_tx_queue include/linux/netdevice.h:2465 [inline] dev_deactivate_many+0x6b1/0xcd0 net/sched/sch_generic.c:1349 __dev_close_many+0x162/0x2b0 net/core/dev.c:1572 dev_close_many+0x21c/0x400 net/core/dev.c:1610 unregister_netdevice_many_notify+0x497/0x1990 net/core/dev.c:10997 unregister_netdevice_many net/core/dev.c:11077 [inline] unregister_netdevice_queue+0x2e5/0x330 net/core/dev.c:10960 unregister_netdevice include/linux/netdevice.h:3075 [inline] __tun_detach+0xdb7/0x1590 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3495 __fput+0x20a/0x8b0 fs/file_table.c:320 task_work_run+0x1d0/0x260 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbe0799ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdaeca72d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fbe07c17da0 RCX: 00007fbe0799ce59 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fbe07c17da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007fbe07c17cb0 R11: 0000000000000246 R12: 00000000001a1b3d R13: 00007fbe07c1618c R14: 00000000001a1988 R15: 00007ffdaeca73e0