INFO: task syz.0.10592:4155 blocked for more than 143 seconds. Not tainted 6.1.132-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.10592 state:D stack:22392 pid:4155 ppid:2891 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 perf_pending_task_sync kernel/events/core.c:5033 [inline] _free_event+0x169/0x1090 kernel/events/core.c:5039 put_event kernel/events/core.c:5164 [inline] perf_event_release_kernel+0x873/0x900 kernel/events/core.c:5289 perf_release+0x37/0x40 kernel/events/core.c:5299 __fput+0x3f6/0x8d0 fs/file_table.c:320 task_work_run+0x246/0x300 kernel/task_work.c:203 get_signal+0x15d0/0x17a0 kernel/signal.c:2648 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f81a4f8d169 RSP: 002b:00007f81a5d31fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffff2 RBX: 00007f81a51a5fa0 RCX: 00007f81a4f8d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007f81a500e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f81a51a5fa0 R15: 00007fff2de577c8 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32e910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 2 locks held by rcu_tasks_trace/13: #0: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 #1: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 1 lock held by khungtaskd/28: #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 1 lock held by syslogd/3605: #0: ffff8880b8f3a998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:537 2 locks held by getty/4012: #0: ffff888031164098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198 3 locks held by kworker/u4:25/11203: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc9000d317d20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 2 locks held by kworker/u4:2/20074: #0: ffff888017c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc9000de17d20 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 2 locks held by kworker/1:1/32466: #0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90003be7d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 3 locks held by kworker/1:0/4950: #0: ffff88814c9f6538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #1: ffffc90003807d20 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267 #2: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xcc/0x16e0 net/ipv6/addrconf.c:4134 1 lock held by syz.6.10982/5527: #0: ffffffff8d38d768 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0xa1/0x340 kernel/trace/bpf_trace.c:2177 2 locks held by syz.3.11000/5577: #0: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x1b0 drivers/net/tun.c:3492 #1: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #1: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962 1 lock held by syz.1.11002/5586: #0: ffffffff8d38d768 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0xa1/0x340 kernel/trace/bpf_trace.c:2177 1 lock held by syz.7.11003/5590: #0: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x4a9/0x2320 drivers/net/tun.c:3104 1 lock held by syz.7.11003/5591: #0: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x4f5/0xf70 net/core/dev_ioctl.c:587 1 lock held by syz.8.11004/5595: #0: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: tun_set_queue drivers/net/tun.c:2975 [inline] #0: ffffffff8e5507a8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x43b/0x2320 drivers/net/tun.c:3097 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.132-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ca/0x430 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+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567