INFO: task kworker/u4:13:5340 blocked for more than 143 seconds. Not tainted 6.1.0-syzkaller-13822-g6feb57c2fd7c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:13 state:D stack:25672 pid:5340 ppid:2 flags:0x00004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0xb8a/0x5450 kernel/sched/core.c:6555 schedule+0xde/0x1b0 kernel/sched/core.c:6631 rxrpc_destroy_all_calls+0x1ee/0x640 net/rxrpc/call_object.c:733 rxrpc_exit_net+0x15c/0x300 net/rxrpc/net_ns.c:125 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:606 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c790c70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c790970 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/28: #0: ffffffff8c7917c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x57/0x264 kernel/locking/lockdep.c:6494 1 lock held by udevd/4429: 2 locks held by getty/4748: #0: ffff888027c6d098 (&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 1 lock held by syz-executor.3/5094: #0: ffffffff8c79c478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #0: ffffffff8c79c478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x5df/0x780 kernel/rcu/tree_exp.h:946 2 locks held by kworker/0:8/5189: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260 #1: ffffc90004cafda8 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264 3 locks held by kworker/u4:13/5340: #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff8880125df938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260 #1: ffffc9000517fda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264 #2: ffffffff8e0aa6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9f/0xb10 net/core/net_namespace.c:568 3 locks held by kworker/1:20/9230: #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline] #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline] #0: ffff888012470d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260 #1: ffffc90015bf7da8 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264 #2: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xf/0x70 net/core/link_watch.c:277 2 locks held by kworker/u4:17/9290: 2 locks held by syz-executor.5/13476: 3 locks held by syz-executor.5/13515: 2 locks held by syz-executor.0/13570: #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:75 [inline] #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e9/0xca0 net/core/rtnetlink.c:6138 #1: ffffffff8c79c478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #1: ffffffff8c79c478 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x24f/0x780 kernel/rcu/tree_exp.h:946 1 lock held by syz-executor.0/13579: #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:75 [inline] #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e9/0xca0 net/core/rtnetlink.c:6138 1 lock held by syz-executor.0/13585: #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:75 [inline] #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e9/0xca0 net/core/rtnetlink.c:6138 1 lock held by syz-executor.0/13589: #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:75 [inline] #0: ffffffff8e0be368 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x3e9/0xca0 net/core/rtnetlink.c:6138 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.1.0-syzkaller-13822-g6feb57c2fd7c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x24/0x18a lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x333/0x3c0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xc75/0xfc0 kernel/hung_task.c:377 kthread+0x2e8/0x3a0 kernel/kthread.c:376 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: 5094 Comm: syz-executor.3 Not tainted 6.1.0-syzkaller-13822-g6feb57c2fd7c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:lock_accessed kernel/locking/lockdep.c:1530 [inline] RIP: 0010:__bfs+0x19b/0x720 kernel/locking/lockdep.c:1754 Code: e8 03 42 80 3c 30 00 0f 85 9a 04 00 00 49 8b 47 10 48 85 c0 0f 84 dd 02 00 00 48 8d 78 4c 48 89 fe 48 c1 ee 03 46 0f b6 0c 36 <48> 89 fe 83 e6 07 83 c6 03 44 38 ce 7c 09 45 84 c9 0f 85 34 04 00 RSP: 0018:ffffc9000446f0a8 EFLAGS: 00000017 RAX: ffffffff9133f8a0 RBX: 0000000000000030 RCX: ffffffff914cab58 RDX: 00000000000003fd RSI: 1ffffffff2267f1d RDI: ffffffff9133f8ec RBP: ffffffff81630d90 R08: ffffffff913b4bd0 R09: 0000000000000000 R10: 00000000000002f3 R11: 00000000000003fb R12: ffffc9000446f1f8 R13: ffffffff914cab68 R14: dffffc0000000000 R15: ffffffff914cab58 FS: 000055555617f400(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1e01385058 CR3: 000000004eb6d000 CR4: 0000000000350ee0 Call Trace: __bfs_backwards kernel/locking/lockdep.c:1849 [inline] check_irq_usage+0x186/0xab0 kernel/locking/lockdep.c:2789 check_prev_add kernel/locking/lockdep.c:3101 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a5b/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 do_write_seqcount_begin_nested include/linux/seqlock.h:516 [inline] do_write_seqcount_begin include/linux/seqlock.h:541 [inline] psi_account_irqtime+0x2a4/0x510 kernel/sched/psi.c:1001 update_rq_clock_task kernel/sched/core.c:704 [inline] update_rq_clock kernel/sched/core.c:747 [inline] update_rq_clock+0x241/0xaa0 kernel/sched/core.c:728 ttwu_queue kernel/sched/core.c:3892 [inline] try_to_wake_up+0xb9a/0x2080 kernel/sched/core.c:4216 wake_up_process kernel/sched/core.c:4350 [inline] wake_up_q+0x82/0xf0 kernel/sched/core.c:1007 __mutex_unlock_slowpath+0x218/0x5e0 kernel/locking/mutex.c:951 kobject_uevent_env+0xc6f/0x1620 lib/kobject_uevent.c:595 disk_event_uevent+0x17b/0x1e0 block/disk-events.c:181 disk_force_media_change+0x22/0xc0 block/disk-events.c:305 __loop_clr_fd+0x3a1/0x8a0 drivers/block/loop.c:1174 lo_release+0x187/0x1c0 drivers/block/loop.c:1745 blkdev_put_whole+0xbb/0xf0 block/bdev.c:695 blkdev_put+0x224/0x770 block/bdev.c:953 btrfs_close_bdev+0xc9/0x170 fs/btrfs/volumes.c:1096 btrfs_close_one_device fs/btrfs/volumes.c:1117 [inline] close_fs_devices fs/btrfs/volumes.c:1159 [inline] close_fs_devices+0x1ca/0x8f0 fs/btrfs/volumes.c:1149 btrfs_close_devices+0x92/0x4b0 fs/btrfs/volumes.c:1174 close_ctree+0xd8b/0xdcf fs/btrfs/disk-io.c:4813 generic_shutdown_super+0x158/0x410 fs/super.c:492 kill_anon_super+0x3a/0x60 fs/super.c:1086 btrfs_kill_super+0x3c/0x50 fs/btrfs/super.c:2132 deactivate_locked_super+0x98/0x160 fs/super.c:332 deactivate_super+0xb1/0xd0 fs/super.c:363 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f40bca8d547 Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc45780ab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f40bca8d547 RDX: 00007ffc45780b8b RSI: 000000000000000a RDI: 00007ffc45780b80 RBP: 00007ffc45780b80 R08: 00000000ffffffff R09: 00007ffc45780950 R10: 00005555561808b3 R11: 0000000000000246 R12: 00007f40bcae6b24 R13: 00007ffc45781c40 R14: 0000555556180810 R15: 00007ffc45781c80