INFO: task syz-executor:4830 blocked for more than 151 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:4830 tgid:4830 ppid:4827 task_flags:0x400140 flags:0x00800010 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1bec/0x2dcc kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x140/0x218 kernel/sched/core.c:7283 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x4e4/0xef8 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 device_lock include/linux/device.h:1040 [inline] device_del+0xa0/0x710 drivers/base/core.c:3857 device_unregister+0x2c/0xf0 drivers/base/core.c:3936 nsim_bus_dev_del+0x60/0x88 drivers/net/netdevsim/bus.c:491 del_device_store+0x248/0x2d0 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:142 kernfs_fop_write_iter+0x264/0x3c0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x52c/0xa14 fs/read_write.c:688 ksys_write+0x12c/0x224 fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 INFO: task syz-executor:4847 blocked for more than 151 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:4847 tgid:4847 ppid:4841 task_flags:0x400140 flags:0x00800000 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1bec/0x2dcc kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x140/0x218 kernel/sched/core.c:7283 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x4e4/0xef8 kernel/locking/mutex.c:820 mutex_lock_nested+0x24/0x30 kernel/locking/mutex.c:873 del_device_store+0xd8/0x2d0 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:142 kernfs_fop_write_iter+0x264/0x3c0 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x52c/0xa14 fs/read_write.c:688 ksys_write+0x12c/0x224 fs/read_write.c:740 __do_sys_write fs/read_write.c:751 [inline] __se_sys_write fs/read_write.c:748 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:748 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Showing all locks held in the system: 4 locks held by kworker/0:0/9: 7 locks held by kworker/u8:0/12: 3 locks held by kworker/u8:1/15: 2 locks held by kworker/1:0/24: 3 locks held by kworker/1:1/26: #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x748/0x1098 kernel/workqueue.c:3397 #1: ffff80008eba7c40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff80008eba7c40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0x750/0x1098 kernel/workqueue.c:3397 #2: ffff800089c3bb80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80 1 lock held by khungtaskd/31: #0: ffff800088b672a0 (rcu_read_lock ){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] ){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] ){....}-{1:3}, at: debug_show_all_locks+0x4c/0x188 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/39: #0: ffff0000c004c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c004c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x748/0x1098 kernel/workqueue.c:3397 #1: ffff80008fff7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff80008fff7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x750/0x1098 kernel/workqueue.c:3397 #2: ffff800089c3bb80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80 6 locks held by kworker/u8:3/40: #0: ffff0000c004e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff0000c004e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x748/0x1098 kernel/workqueue.c:3397 #1: ffff800090007c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #1: ffff800090007c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x750/0x1098 kernel/workqueue.c:3397 #2: ffff800089c2e6a8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x100/0x6b8 net/core/net_namespace.c:673