INFO: task kworker/u4:4:22385 blocked for more than 146 seconds. Not tainted 6.1.0-syzkaller-13064-g75caf5940899 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:24608 pid:22385 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x9d1/0xe40 kernel/sched/core.c:6555 schedule+0xcb/0x190 kernel/sched/core.c:6631 rxrpc_destroy_all_calls+0x585/0x680 net/rxrpc/call_object.c:733 rxrpc_exit_net+0x6a/0xc0 net/rxrpc/net_ns.c:125 ops_exit_list net/core/net_namespace.c:169 [inline] cleanup_net+0x758/0xc60 net/core/net_namespace.c:606 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d3238d0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d3240d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8d323700 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4741: #0: ffff88802c503098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6e8/0x1e50 drivers/tty/n_tty.c:2177 2 locks held by kworker/0:14/22021: #0: ffff888012866538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc900053bfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 3 locks held by kworker/u4:4/22385: #0: ffff8880129cb138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc9000aff7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 #2: ffffffff8e456350 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf0/0xc60 net/core/net_namespace.c:568 2 locks held by syz-executor.5/24234: #0: ffff88802a84c0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: grab_super+0x58/0x190 fs/super.c:386 #1: ffffffff8d34b2e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_do_get_tree+0x1a9/0x670 kernel/cgroup/cgroup.c:2170 7 locks held by syz-executor.2/24236: #0: ffff88802a39d9e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x242/0x2e0 fs/file.c:1046 #1: ffff88802a84c460 (sb_writers#10){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:933 [inline] #1: ffff88802a84c460 (sb_writers#10){.+.+}-{0:0}, at: do_writev+0x266/0x470 fs/read_write.c:977 #2: ffff88814aaaf888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1f3/0x500 fs/kernfs/file.c:325 #3: ffffffff8d34b2e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe4/0x280 kernel/cgroup/cgroup.c:1673 #4: ffffffff8d1c0ff0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2435 [inline] #4: ffffffff8d1c0ff0 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x196/0x600 kernel/cgroup/cgroup.c:2939 #5: ffffffff8d34b4d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2437 [inline] #5: ffffffff8d34b4d0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1ab/0x600 kernel/cgroup/cgroup.c:2939 #6: ffffffff8d328d38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #6: ffffffff8d328d38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a6/0x890 kernel/rcu/tree_exp.h:946 4 locks held by syz-executor.2/24239: #0: ffff88802a39cfe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x242/0x2e0 fs/file.c:1046 #1: ffff88802a84c460 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x275/0xbb0 fs/read_write.c:580 #2: ffff88814aaaf088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1f3/0x500 fs/kernfs/file.c:325 #3: ffffffff8d34b2e8 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xe4/0x280 kernel/cgroup/cgroup.c:1673 1 lock held by syz-executor.3/24237: #0: ffff88802a84c0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: grab_super+0x58/0x190 fs/super.c:386 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-syzkaller-13064-g75caf5940899 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e3/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x19b/0x3e0 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+0xcd5/0xd20 kernel/hung_task.c:377 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 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:112 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry drivers/acpi/processor_idle.c:570 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_enter+0x43d/0x800 drivers/acpi/processor_idle.c:707