INFO: task syz-executor.3:12656 blocked for more than 143 seconds. Not tainted 6.3.0-rc7-next-20230421-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:24064 pid:12656 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5334 [inline] __schedule+0x1d23/0x5650 kernel/sched/core.c:6659 schedule+0xde/0x1a0 kernel/sched/core.c:6735 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6794 rwsem_down_write_slowpath+0x3e2/0x1220 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write+0x1d2/0x200 kernel/locking/rwsem.c:1574 unregister_netdevice_notifier+0x22/0x180 net/core/dev.c:1757 devlink_free+0x2cb/0x460 net/devlink/core.c:269 nsim_drv_remove+0x158/0x1d0 drivers/net/netdevsim/dev.c:1687 device_remove+0xc8/0x170 drivers/base/dd.c:567 __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x443/0x610 drivers/base/dd.c:1295 bus_remove_device+0x22c/0x420 drivers/base/bus.c:574 device_del+0x399/0xa30 drivers/base/core.c:3814 device_unregister+0x1e/0xc0 drivers/base/core.c:3844 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline] del_device_store+0x34e/0x4a0 drivers/net/netdevsim/bus.c:219 bus_attr_store+0x76/0xa0 drivers/base/bus.c:170 sysfs_kf_write+0x114/0x170 fs/sysfs/file.c:136 kernfs_fop_write_iter+0x3f1/0x600 fs/kernfs/file.c:334 call_write_iter include/linux/fs.h:1854 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0xa1d/0xe40 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f451d83deef RSP: 002b:00007fff7af1cfb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f451d83deef RDX: 0000000000000001 RSI: 00007fff7af1d000 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 00007fff7af1cf50 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f451d8e78b6 R13: 00007fff7af1d000 R14: 0000000000000000 R15: 00007fff7af1d6d0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c7977b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c7974b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c7983c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6545 2 locks held by getty/4755: #0: ffff88802826b098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 3 locks held by kworker/u4:7/5259: 3 locks held by kworker/u4:20/5433: 6 locks held by syz-executor.3/12656: #0: ffff888018a9c460 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:637 #1: ffff88802b186088 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x285/0x600 fs/kernfs/file.c:325 #2: ffff88814704ee88 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2a9/0x600 fs/kernfs/file.c:326 #3: ffffffff8d7ea848 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xc9/0x4a0 drivers/net/netdevsim/bus.c:209 #4: ffff888030ee70e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #4: ffff888030ee70e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff888030ee70e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1292 #5: ffffffff8e0f1590 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x22/0x180 net/core/dev.c:1757 1 lock held by syz-executor.3/12718: #0: ffffffff8e0f1590 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4cb/0x8e0 net/core/net_namespace.c:487 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc7-next-20230421-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x33e/0x440 kernel/kthread.c:379 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: 5259 Comm: kworker/u4:7 Not tainted 6.3.0-rc7-next-20230421-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Workqueue: netns cleanup_net RIP: 0010:hlist_nulls_empty include/linux/list_nulls.h:88 [inline] RIP: 0010:get_next_corpse net/netfilter/nf_conntrack_core.c:2368 [inline] RIP: 0010:nf_ct_iterate_cleanup+0xc0/0x500 net/netfilter/nf_conntrack_core.c:2419 Code: 3a 38 f9 41 39 dd 0f 83 38 03 00 00 e8 99 3e 38 f9 48 8b 15 72 73 2e 06 44 89 e8 48 8d 1c c2 48 89 d8 48 c1 e8 03 80 3c 28 00 <0f> 85 fe 03 00 00 4c 8b 33 31 ff 41 83 e6 01 44 89 f6 e8 89 3a 38 RSP: 0018:ffffc90004dc7ac0 EFLAGS: 00000246 RAX: 1ffff11004fb922a RBX: ffff888027dc9150 RCX: 0000000000000000 RDX: ffff888027c00000 RSI: ffffffff884ba6b7 RDI: 0000000000000004 RBP: dffffc0000000000 R08: 0000000000000004 R09: 000000000003922a R10: 0000000000040000 R11: 0000000000000000 R12: ffffc90004dc7b98 R13: 000000000003922a R14: 0000000000000001 R15: 0000000000005180 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000010c1248 CR3: 0000000020423000 CR4: 00000000003506f0 Call Trace: nf_ct_iterate_cleanup_net+0xdb/0x110 net/netfilter/nf_conntrack_core.c:2440 nf_conntrack_cleanup_net_list+0x1cc/0x5d0 net/netfilter/nf_conntrack_core.c:2553 ops_exit_list+0x125/0x170 net/core/net_namespace.c:175 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:614 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x33e/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308