INFO: task syz-executor:4833 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:4833  tgid:4833  ppid:1      task_flags:0x400140 flags:0x00000001
Call trace:
 __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:775 (T)
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1370/0x2d80 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x13c/0x20c kernel/sched/core.c:7326
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7383
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x4ec/0xf14 kernel/locking/mutex.c:821
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
 del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
 bus_attr_store+0x80/0xa4 drivers/base/bus.c:172
 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
INFO: task syz-executor:4837 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:4837  tgid:4837  ppid:1      task_flags:0x400140 flags:0x00800001
Call trace:
 __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:775 (T)
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1370/0x2d80 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x13c/0x20c kernel/sched/core.c:7326
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7383
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x4ec/0xf14 kernel/locking/mutex.c:821
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
 del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
 bus_attr_store+0x80/0xa4 drivers/base/bus.c:172
 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
INFO: task syz-executor:4842 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:0     pid:4842  tgid:4842  ppid:4838   task_flags:0x400140 flags:0x00800000
Call trace:
 __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:775 (T)
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x1370/0x2d80 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x13c/0x20c kernel/sched/core.c:7326
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7383
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x4ec/0xf14 kernel/locking/mutex.c:821
 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:874
 device_lock include/linux/device.h:1102 [inline]
 device_del+0xa4/0x71c drivers/base/core.c:3923
 device_unregister+0x2c/0xf0 drivers/base/core.c:4002
 nsim_bus_dev_del+0x60/0x8c drivers/net/netdevsim/bus.c:491
 del_device_store+0x24c/0x2d4 drivers/net/netdevsim/bus.c:244
 bus_attr_store+0x80/0xa4 drivers/base/bus.c:172
 sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594

Showing all locks held in the system:
6 locks held by kworker/u8:1/15:
 #0: ffff0000c004e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff0000c004e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3405
 #1: ffff80008ec47c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffff80008ec47c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3405
 #2: ffff800089d85fe8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x104/0x6c4 net/core/net_namespace.c:673
 #3: ffff0000ca359128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
 #3: ffff0000ca359128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
 #3: ffff0000ca359128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x108/0x30c net/devlink/core.c:557
 #4: ffff0000ca358258 (&devlink->lock_key){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
 #4: ffff0000ca358258 (&devlink->lock_key){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
 #4: ffff0000ca358258 (&devlink->lock_key){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x30c net/devlink/core.c:557
 #5: ffff800089d93380 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
1 lock held by khungtaskd/31:
 #0: ffff800088cb6f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff800088cb6f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffff800088cb6f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x4c/0x188 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/40:
 #0: ffff0000c004b940 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff0000c004b940 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3405
 #1: ffff80008eff7c40 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffff80008eff7c40 ((crda_timeout).work){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3405
 #2: ffff800089d93380 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
3 locks held by pr/ttyAMA-1/41:
2 locks held by kworker/1:2/867:
3 locks held by kworker/u8:6/3864:
3 locks held by udevd/4343:
3 locks held by dhcpcd/4398:
4 locks held by kworker/1:3/4469:
2 locks held by getty/4491:
 #0: ffff0000c8e360a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009248b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x348/0xf78 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/4725:
4 locks held by syz-executor/4833:
 #0: ffff0000cef8c450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000cef8c450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000f1ac9880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000c9d923c8 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000c9d923c8 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff800089583e00 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
4 locks held by syz-executor/4837:
 #0: ffff0000cef8c450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000cef8c450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000f1ac8480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000c9d923c8 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000c9d923c8 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff800089583e00 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
5 locks held by syz-executor/4842:
 #0: ffff0000cef8c450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000cef8c450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000f1a95880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000c9d923c8 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000c9d923c8 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff800089583e00 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
 #4: ffff0000ca359128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline]
 #4: ffff0000ca359128 (&dev->mutex){....}-{4:4}, at: device_del+0xa4/0x71c drivers/base/core.c:3923
3 locks held by syz-executor/4859:
2 locks held by kworker/u8:8/4965:
3 locks held by kworker/u8:10/4967:
 #0: ffff0000ce48d940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff0000ce48d940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3405
 #1: ffff8000969c7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffff8000969c7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3405
 #2: ffff800089d93380 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
3 locks held by kworker/u8:11/4970:
3 locks held by kworker/u8:12/4971:
 #0: ffff0000c004c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff0000c004c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3405
 #1: ffff800098387c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffff800098387c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3405
 #2: ffff800089d93380 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
3 locks held by kworker/u8:14/4975:
2 locks held by syz-executor/4978:

=============================================