INFO: task syz-executor:4852 blocked for more than 143 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:4852  tgid:4852  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+0x84/0x98 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:758
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
INFO: task syz-executor:4855 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:4855  tgid:4855  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
 device_lock include/linux/device.h:1104 [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+0x84/0x98 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:758
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
INFO: task syz-executor:4862 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:4862  tgid:4862  ppid:4860   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
 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+0x84/0x98 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:758
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590
INFO: task syz-executor:4871 blocked for more than 146 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:4871  tgid:4871  ppid:4866   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
 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+0x84/0x98 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:758
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:777
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:590

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
 #0: ffff800088d271a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffff800088d271a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffff800088d271a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x4c/0x188 kernel/locking/lockdep.c:6775
8 locks held by kworker/u8:4/1192:
3 locks held by kworker/u8:6/3546:
 #0: ffff0000cee52140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff0000cee52140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x734/0x10b8 kernel/workqueue.c:3405
 #1: ffff800094d77c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffff800094d77c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x73c/0x10b8 kernel/workqueue.c:3405
 #2: ffff800089e14680 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
7 locks held by kworker/u8:8/3749:
2 locks held by udevd/4345:
3 locks held by dhcpcd/4400:
2 locks held by kworker/1:3/4476:
2 locks held by getty/4496:
 #0: ffff0000c964a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009250b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x348/0xf78 drivers/tty/n_tty.c:2211
4 locks held by syz-executor/4852:
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000d0f90480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff8000895f4e20 (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/4855:
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000f12fec80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff8000895f4e20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
 #4: ffff0000dc5a6128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff0000dc5a6128 (&dev->mutex){....}-{4:4}, at: device_del+0xa4/0x71c drivers/base/core.c:3923
4 locks held by syz-executor/4862:
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000e01a2880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff8000895f4e20 (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/4871:
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline]
 #0: ffff0000d1780450 (sb_writers#6){.+.+}-{0:0}, at: vfs_write+0x248/0xa0c fs/read_write.c:683
 #1: ffff0000f12b2c80 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1b0/0x3b8 fs/kernfs/file.c:336
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff0000ca6b0008 (kn->active#55){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x1f0/0x3b8 fs/kernfs/file.c:337
 #3: ffff8000895f4e20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd8/0x2d4 drivers/net/netdevsim/bus.c:234
2 locks held by kworker/u8:10/4972:
2 locks held by udevd/4977:
3 locks held by syz-executor/4984:
2 locks held by syz-executor/4985:
2 locks held by syz-executor/4989:

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