INFO: task syz-executor.3:9735 blocked for more than 143 seconds. Not tainted 6.3.0-syzkaller-04439-g4173cf6fb6b7 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:25064 pid:9735 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5307 [inline] __schedule+0xc91/0x5770 kernel/sched/core.c:6625 schedule+0xde/0x1a0 kernel/sched/core.c:6701 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6760 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:1759 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:540 __device_release_driver drivers/base/dd.c:1240 [inline] device_release_driver_internal+0x443/0x610 drivers/base/dd.c:1263 bus_remove_device+0x22c/0x420 drivers/base/bus.c:574 device_del+0x48a/0xb80 drivers/base/core.c:3775 device_unregister+0x1e/0xc0 drivers/base/core.c:3805 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:1851 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9e5/0xe00 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: 0033:0x7f6eb523deef RSP: 002b:00007f6eb54cf220 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f6eb523deef RDX: 0000000000000001 RSI: 00007f6eb54cf270 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 00007f6eb54cf1c0 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f6eb52e78b6 R13: 00007f6eb54cf270 R14: 0000000000000000 R15: 00007f6eb54cf940 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c7950b0 (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: ffffffff8c794db0 (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: ffffffff8c795cc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6545 2 locks held by getty/4740: #0: ffff888027dc9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177 2 locks held by kworker/u4:9/30023: 4 locks held by kworker/u4:5/14054: #0: ffff888016617938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888016617938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888016617938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888016617938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888016617938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888016617938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc900038bfda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 #2: ffffffff8e0e0e50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9f/0xb10 net/core/net_namespace.c:576 #3: ffffffff8c7a1000 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6a0 kernel/rcu/tree.c:3961 6 locks held by syz-executor.3/9735: #0: ffff88807f0c2460 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12b/0x250 fs/read_write.c:637 #1: ffff8880ac644c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x285/0x600 fs/kernfs/file.c:325 #2: ffff8880211a8578 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x2a9/0x600 fs/kernfs/file.c:326 #3: ffffffff8d7e0748 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xc9/0x4a0 drivers/net/netdevsim/bus.c:209 #4: ffff888040d450e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:832 [inline] #4: ffff888040d450e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1063 [inline] #4: ffff888040d450e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa4/0x610 drivers/base/dd.c:1260 #5: ffffffff8e0e0e50 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x22/0x180 net/core/dev.c:1759 1 lock held by syz-executor.3/9958: #0: ffffffff8e0e0e50 (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-syzkaller-04439-g4173cf6fb6b7 #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+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: 14586 Comm: kworker/u4:22 Not tainted 6.3.0-syzkaller-04439-g4173cf6fb6b7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:228 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:240 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4746 [inline] RIP: 0010:__lock_acquire+0x402/0x5df0 kernel/locking/lockdep.c:5024 Code: 00 41 89 44 24 24 48 8b 6c 24 10 be 08 00 00 00 81 e5 ff 1f 00 00 48 89 e8 48 c1 e8 06 48 8d 3c c5 c0 5b 4d 91 e8 ce e6 6f 00 <48> 0f a3 2d f6 eb e8 0f 0f 83 34 0d 00 00 48 8d 6c 6d 00 48 c1 e5 RSP: 0018:ffffc90003a7fa28 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff8c795cc0 RCX: ffffffff81646fc2 RDX: fffffbfff229ab79 RSI: 0000000000000008 RDI: ffffffff914d5bc0 RBP: 0000000000000021 R08: 0000000000000000 R09: ffffffff914d5bc7 R10: fffffbfff229ab78 R11: 0000000000000000 R12: ffff8880afb44698 R13: ffff8880afb43b80 R14: 0000000000020000 R15: 0000000000020021 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0081d7238 CR3: 000000000c571000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5691 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5656 rcu_lock_acquire include/linux/rcupdate.h:327 [inline] rcu_read_lock include/linux/rcupdate.h:773 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x131/0xfe0 net/batman-adv/network-coding.c:719 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x33e/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308