INFO: task syz.1.2:4377 blocked for more than 143 seconds. Not tainted 6.1.146-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2 state:D stack:22976 pid:4377 ppid:4268 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x171/0x10a0 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 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+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0c5298e9a9 RSP: 002b:00007f0c53784fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f0c52bb5fa0 RCX: 00007f0c5298e9a9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007f0c52a10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f0c52bb5fa0 R15: 00007fff9e06c9e8 Showing all locks held in the system: 3 locks held by kworker/u4:1/11: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000107d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd332d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b7b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bfd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by kworker/1:2/128: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90002da7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 2 locks held by getty/4026: #0: ffff88814d15b098 (&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+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by syz.5.1161/8061: #0: ffffffff8dd332d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8dd3ff68 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc8/0x360 net/ipv4/ip_tunnel.c:1166 #2: ffffffff8cb30af8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline] #2: ffffffff8cb30af8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962 1 lock held by syz.4.1165/8071: #0: ffffffff8dd3ff68 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dd3ff68 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3492 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 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+0xeee/0xf30 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: 128 Comm: kworker/1:2 Not tainted 6.1.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events pwq_unbound_release_workfn RIP: 0010:remove_class_from_lock_chain kernel/locking/lockdep.c:5952 [inline] RIP: 0010:remove_class_from_lock_chains kernel/locking/lockdep.c:5991 [inline] RIP: 0010:zap_class+0x160/0x830 kernel/locking/lockdep.c:6036 Code: 3f 4d 85 ff 0f 94 c0 49 83 c7 f8 0f 94 c1 08 c1 75 b5 4d 89 fd 49 c1 ed 03 43 0f b6 44 35 00 84 c0 0f 85 45 02 00 00 45 8b 27 <41> f6 c4 fc 0f 84 03 02 00 00 41 c1 ec 08 44 89 e5 01 ed 49 81 fc RSP: 0018:ffffc90002da7ac8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000980 RCX: 0000000000026f00 RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8fa72f0e RBP: 000000000004de10 R08: dffffc0000000000 R09: fffffbfff215ba6f R10: fffffbfff215ba6f R11: 1ffffffff215ba6e R12: 0000000001ad6918 R13: 1ffffffff2174c84 R14: dffffc0000000000 R15: ffffffff90ba6420 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc59ccbd18 CR3: 000000002482e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lockdep_free_key_range kernel/locking/lockdep.c:6162 [inline] lockdep_unregister_key+0x38f/0x530 kernel/locking/lockdep.c:6364 wq_unregister_lockdep kernel/workqueue.c:3500 [inline] pwq_unbound_release_workfn+0x262/0x2b0 kernel/workqueue.c:3738 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295