INFO: task kworker/u4:19:5844 blocked for more than 143 seconds. Not tainted 6.1.0-syzkaller-13409-g2f26e424552e #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:19 state:D stack:21016 pid:5844 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: ffffffff8d323910 (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: ffffffff8d324110 (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: ffffffff8d323740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4740: #0: ffff88802c7aa098 (&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 1 lock held by syz-executor.3/5087: #0: ffffffff8d328d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #0: ffffffff8d328d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x46f/0x890 kernel/rcu/tree_exp.h:946 1 lock held by syz-executor.2/5092: #0: ffffffff8d328d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #0: ffffffff8d328d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a6/0x890 kernel/rcu/tree_exp.h:946 2 locks held by kworker/1:10/5809: #0: ffff888012872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc9000b7efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 3 locks held by kworker/u4:19/5844: #0: ffff8880129db138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x796/0xd10 kernel/workqueue.c:2262 #1: ffffc9000b88fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0xd10 kernel/workqueue.c:2264 #2: ffffffff8e4563d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf0/0xc60 net/core/net_namespace.c:568 1 lock held by syz-executor.5/29331: 2 locks held by syz-executor.5/29356: 3 locks held by syz-executor.5/29391: 1 lock held by syz-executor.0/29407: 2 locks held by syz-executor.5/29420: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.0-syzkaller-13409-g2f26e424552e #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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22736 Comm: kworker/u4:75 Not tainted 6.1.0-syzkaller-13409-g2f26e424552e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:lock_acquire+0x1ed/0x400 kernel/locking/lockdep.c:5671 Code: 7e 83 f8 01 0f 85 96 01 00 00 49 89 de 48 c1 eb 03 42 80 3c 23 00 74 08 4c 89 f7 e8 8d e1 77 00 48 c7 44 24 60 00 00 00 00 9c <8f> 44 24 60 42 80 3c 23 00 74 08 4c 89 f7 e8 f0 e0 77 00 f6 44 24 RSP: 0018:ffffc9001597f838 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 1ffff92002b2ff14 RCX: ffff88807ede44b0 RDX: dffffc0000000000 RSI: ffffffff8aeda9e0 RDI: ffffffff8b497600 RBP: ffffc9001597f988 R08: dffffc0000000000 R09: fffffbfff20ec03c R10: fffffbfff20ec03c R11: 1ffffffff20ec03b R12: dffffc0000000000 R13: 1ffff92002b2ff10 R14: ffffc9001597f8a0 R15: 0000000000000046 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002016d030 CR3: 000000001d732000 CR4: 00000000003506f0 DR0: 00000000ffff070c DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 ext4_finish_bio+0x4ff/0xbb0 fs/ext4/page-io.c:128 ext4_release_io_end+0xe3/0x2f0 fs/ext4/page-io.c:160 ext4_end_io_end fs/ext4/page-io.c:194 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline] ext4_end_io_rsv_work+0x5c1/0x6f0 fs/ext4/page-io.c:273 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