INFO: task syz-executor.5:24721 blocked for more than 143 seconds. Not tainted 6.3.0-syzkaller-10656-g22b8cc3e78f5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:20792 pid:24721 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5309 [inline] __schedule+0x173b/0x4630 kernel/sched/core.c:6627 schedule+0xc3/0x180 kernel/sched/core.c:6703 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6762 rwsem_down_write_slowpath+0xedd/0x13a0 kernel/locking/rwsem.c:1178 __down_write_common+0x1aa/0x200 kernel/locking/rwsem.c:1306 unregister_netdevice_notifier+0x92/0x400 net/core/dev.c:1757 devlink_free+0x279/0x430 net/devlink/core.c:269 nsim_drv_remove+0x139/0x160 drivers/net/netdevsim/dev.c:1687 device_remove drivers/base/dd.c:567 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x4a5/0x7a0 drivers/base/dd.c:1295 bus_remove_device+0x341/0x410 drivers/base/bus.c:574 device_del+0x538/0x9c0 drivers/base/core.c:3814 device_unregister+0x20/0xc0 drivers/base/core.c:3844 nsim_bus_dev_del drivers/net/netdevsim/bus.c:310 [inline] del_device_store+0x363/0x480 drivers/net/netdevsim/bus.c:219 kernfs_fop_write_iter+0x3a6/0x4f0 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+0x7ec/0xc10 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f98cac3deef RSP: 002b:00007fffadbc0560 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f98cac3deef RDX: 0000000000000001 RSI: 00007fffadbc05b0 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 00007fffadbc0500 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f98cace78b6 R13: 00007fffadbc05b0 R14: 0000000000000000 R15: 00007fffadbc0c80 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf25fb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf26370 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8cf25de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/4744: #0: ffff88814aee9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176 4 locks held by kworker/u4:14/5906: 6 locks held by syz-executor.5/24721: #0: ffff88801b692460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x27f/0xc10 fs/read_write.c:580 #1: ffff88814af55488 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1eb/0x4f0 fs/kernfs/file.c:325 #2: ffff8881417890f0 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20f/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8da0cd68 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:209 #4: ffff88807df4e0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:837 [inline] #4: ffff88807df4e0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88807df4e0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7a0 drivers/base/dd.c:1292 #5: ffffffff8e08b150 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x92/0x400 net/core/dev.c:1757 1 lock held by syz-executor.5/24737: #0: ffffffff8e08b150 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x4af/0x790 net/core/net_namespace.c:487 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.3.0-syzkaller-10656-g22b8cc3e78f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 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+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:379 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 CPU: 1 PID: 10351 Comm: kworker/u4:23 Not tainted 6.3.0-syzkaller-10656-g22b8cc3e78f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:lock_release+0x5/0x9d0 kernel/locking/lockdep.c:5699 Code: 0f 8c 24 f6 ff ff 48 c7 c7 e8 55 55 8e e8 93 30 78 00 e9 13 f6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 00 01 00 RSP: 0018:ffffc90014187be8 EFLAGS: 00000293 RAX: ffffffff8a7e50ee RBX: 0000000000000001 RCX: ffff88802d11bb80 RDX: 0000000000000000 RSI: ffffffff8a7e50e5 RDI: ffffffff8cf25de0 RBP: 0000000000000001 R08: ffffffff8a7dd5b9 R09: fffffbfff2063655 R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000000000ab R13: dffffc0000000000 R14: ffff888039030c80 R15: ffff88807b390680 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00a6ef000 CR3: 000000000cd30000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:806 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x23d/0x5c0 net/batman-adv/network-coding.c:719 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2390 worker_thread+0xa63/0x1210 kernel/workqueue.c:2537 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308