INFO: task syz-executor:8356 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21960 pid:8356 tgid:8356 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 kthread_stop+0x194/0x5f0 kernel/kthread.c:791 bch2_copygc_stop+0x4f/0x150 fs/bcachefs/movinggc.c:438 __bch2_fs_read_only+0x47/0x5b0 fs/bcachefs/super.c:280 bch2_fs_read_only+0x42a/0xb00 fs/bcachefs/super.c:366 __bch2_fs_stop+0x100/0x900 fs/bcachefs/super.c:677 generic_shutdown_super+0x132/0x2c0 fs/super.c:643 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7dadb8fc57 RSP: 002b:00007ffc6aa90438 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f7dadc10925 RCX: 00007f7dadb8fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc6aa904f0 RBP: 00007ffc6aa904f0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc6aa91580 R13: 00007f7dadc10925 R14: 000000000004a12b R15: 00007ffc6aa915c0 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 6 locks held by kworker/u8:5/1080: #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2fb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000445fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000445fbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f4feb50 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662 #3: ffff8880315750e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #3: ffff8880315750e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880315750e8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506 #4: ffff888031576250 (&devlink->lock_key#10){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff888031576250 (&devlink->lock_key#10){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff888031576250 (&devlink->lock_key#10){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506 #5: ffffffff8f50b748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8f50b748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2143 1 lock held by dhcpcd/5501: #0: ffffffff8f50b748 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f50b748 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_deladdr+0x198/0x740 net/ipv4/devinet.c:671 2 locks held by getty/5599: #0: ffff8880312970a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/8356: #0: ffff8880480060e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880480060e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880480060e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff88805c600278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676 2 locks held by bch-copygc/loop/9645: #0: ffff88805c604398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #0: ffff88805c604398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #0: ffff88805c604398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3299 #1: ffff88805c626710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211 1 lock held by syz.5.617/12492: #0: ffffffff8f50b748 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f50b748 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3396 3 locks held by syz.0.615/12498: #0: ffff888052b18dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff888052b18dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2717 #1: ffff888052b180b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282 #2: ffffffff8f6739c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2067 [inline] #2: ffffffff8f6739c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2560 1 lock held by syz.6.619/12516: #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 4 locks held by syz.2.620/12531: #0: ffff888056c8cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff888056c8cdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2717 #1: ffff888056c8c0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5282 #2: ffffffff8f6739c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2067 [inline] #2: ffffffff8f6739c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2560 #3: ffff888076618b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762 1 lock held by udevadm/12573: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12573 Comm: udevadm Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:percpu_counter_add_batch+0x0/0x1e0 lib/percpu_counter.c:94 Code: 41 5e 41 5f 5d e9 f0 af 7c 06 e8 bb 1c d2 fc eb ba 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 41 89 d4 49 RSP: 0018:ffffc9000c617d68 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff888075d2a1c0 RCX: ffff888025a8bc00 RDX: 0000000000000020 RSI: ffffffffffffffff RDI: ffffffff8de16740 RBP: 0000000000000000 R08: ffffffff8fa0cbf7 R09: 1ffffffff1f4197e R10: dffffc0000000000 R11: fffffbfff1f4197f R12: ffff888075d2a200 R13: dffffc0000000000 R14: ffff88801dae8fe0 R15: 0000000000000000 FS: 00007f66c7c95880(0000) GS:ffff888125d4f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a5935945f8 CR3: 0000000078a30000 CR4: 00000000003526f0 Call Trace: percpu_counter_add include/linux/percpu_counter.h:71 [inline] percpu_counter_dec include/linux/percpu_counter.h:272 [inline] file_free fs/file_table.c:70 [inline] __fput+0x729/0xa70 fs/file_table.c:478 fput_close_sync+0x119/0x200 fs/file_table.c:570 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66c7515a67 Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffddbdc1648 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 000055a5935812a0 RCX: 00007f66c7515a67 RDX: 00007f66c75efea0 RSI: 000055a593593dd0 RDI: 0000000000000005 RBP: 00007f66c75efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544