INFO: task kworker/u4:9:5267 blocked for more than 164 seconds. Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:9 state:D stack:23576 pid:5267 tgid:5267 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0x17df/0x4a40 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6804 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6819 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 __flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617 drain_workqueue+0xc9/0x390 kernel/workqueue.c:3730 destroy_workqueue+0xba/0xc40 kernel/workqueue.c:5319 bond_destructor+0x4d/0x80 drivers/net/bonding/bond_main.c:5846 netdev_run_todo+0xd4f/0xf40 net/core/dev.c:10581 default_device_exit_batch+0x975/0x9f0 net/core/dev.c:11625 ops_exit_list net/core/net_namespace.c:175 [inline] cleanup_net+0x775/0xb90 net/core/net_namespace.c:618 process_one_work kernel/workqueue.c:3049 [inline] process_scheduled_works+0x913/0x14f0 kernel/workqueue.c:3125 worker_thread+0xa60/0x1000 kernel/workqueue.c:3206 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: #0: ffff8880b943c758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:567 1 lock held by khungtaskd/29: #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 2 locks held by getty/4827: #0: ffff88802a1d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201 3 locks held by kworker/u4:9/5267: #0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline] #0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125 #1: ffffc9000475fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline] #1: ffffc9000475fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125 #2: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf5/0xb90 net/core/net_namespace.c:580 2 locks held by syz-executor.4/10946: #0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491 #1: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xce/0x370 net/ipv4/ip_tunnel.c:1139 2 locks held by syz-executor.2/10948: #0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491 #1: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xce/0x370 net/ipv4/ip_tunnel.c:1139 3 locks held by syz-executor.3/10953: #0: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4c8/0x7b0 net/core/net_namespace.c:491 #1: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xce/0x370 net/ipv4/ip_tunnel.c:1139 #2: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #2: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x39a/0x820 kernel/rcu/tree_exp.h:939 1 lock held by syz-executor.1/10966: #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x82c/0x1040 net/core/rtnetlink.c:6612 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfb0/0xff0 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 70 Comm: kworker/u4:5 Not tainted 6.8.0-rc2-next-20240202-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: 0x0 (bat_events) RIP: 0010:switch_mm_irqs_off+0x492/0xae0 arch/x86/mm/tlb.c:561 Code: b8 00 00 00 00 00 fc ff df 41 80 3c 04 00 74 08 4c 89 ef e8 b0 e8 b4 00 49 3b 5d 00 0f 85 13 01 00 00 45 31 ff e9 f8 01 00 00 <66> 41 83 ff 06 0f 83 03 05 00 00 4c 89 6c 24 40 49 c1 e5 04 4c 89 RSP: 0018:ffffc900015e7a80 EFLAGS: 00000046 RAX: 000000002bcce000 RBX: ffff888024e68000 RCX: ffff8880183c3c00 RDX: 0000000040000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900015e7b70 R08: ffffffff8141cf6c R09: 1ffff11003078a2c R10: dffffc0000000000 R11: ffffed1003078a2d R12: 000000002bcce000 R13: 0000000000000000 R14: ffff88806c43a600 R15: 1ffff11003070000 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8e67fa8000 CR3: 000000002bcce000 CR4: 00000000003506f0 Call Trace: context_switch kernel/sched/core.c:5384 [inline] __schedule+0x105d/0x4a40 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6804 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6819 worker_thread+0xc27/0x1000 kernel/workqueue.c:3221 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242