INFO: task syz-executor:5226 blocked for more than 143 seconds. Not tainted 6.11.0-rc3-next-20240816-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:19792 pid:5226 tgid:5226 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5270 [inline] __schedule+0x17ff/0x4ad0 kernel/sched/core.c:6639 __schedule_loop kernel/sched/core.c:6716 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6731 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2557 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+0x355/0x620 kernel/sched/completion.c:148 kthread_stop+0x19e/0x640 kernel/kthread.c:710 ext4_stop_mmpd+0x47/0xb0 fs/ext4/mmp.c:261 ext4_put_super+0x753/0xd50 fs/ext4/super.c:1365 generic_shutdown_super+0x139/0x2d0 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1696 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7289 deactivate_locked_super+0xc4/0x130 fs/super.c:473 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f784957ace7 RSP: 002b:00007fff624b0e48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f784957ace7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff624b0f00 RBP: 00007fff624b0f00 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff624b1f80 R13: 00007f78495e7764 R14: 000000000001cbc9 R15: 00007fff624b1fc0 INFO: task kmmpd-loop2:6634 blocked for more than 144 seconds. Not tainted 6.11.0-rc3-next-20240816-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kmmpd-loop2 state:D stack:26776 pid:6634 tgid:6634 ppid:2 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5270 [inline] __schedule+0x17ff/0x4ad0 kernel/sched/core.c:6639 __schedule_loop kernel/sched/core.c:6716 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6731 percpu_rwsem_wait+0x3c2/0x450 kernel/locking/percpu-rwsem.c:162 __percpu_down_read+0xee/0x130 kernel/locking/percpu-rwsem.c:177 percpu_down_read include/linux/percpu-rwsem.h:65 [inline] __sb_start_write include/linux/fs.h:1686 [inline] sb_start_write include/linux/fs.h:1822 [inline] write_mmp_block+0x2f2/0x3a0 fs/ext4/mmp.c:66 kmmpd+0x26d/0xaa0 fs/ext4/mmp.c:246 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 6 locks held by kworker/u8:0/11: 3 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e939720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e939720 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e939720 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6645 2 locks held by getty/4978: #0: ffff88802b7cb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5226: #0: ffff88801f56e0e0 (&type->s_umount_key#33){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88801f56e0e0 (&type->s_umount_key#33){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88801f56e0e0 (&type->s_umount_key#33){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 1 lock held by kmmpd-loop2/6634: #0: ffff88801f56e420 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x26d/0xaa0 fs/ext4/mmp.c:246 3 locks held by kworker/u8:11/8658: #0: ffff888015889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] #0: ffff888015889148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3313 #1: ffffc90002527d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3208 [inline] #1: ffffc90002527d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3313 #2: ffffffff8fc90548 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 3 locks held by syz.1.1030/8733: #0: ffff888023ebcd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888023ebcd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2692 #1: ffff888023ebc078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5145 #2: ffffffff8fdfc468 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1977 [inline] #2: ffffffff8fdfc468 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592 3 locks held by syz.2.1035/8743: #0: ffff888079514d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888079514d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2692 #1: ffff888079514078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x572/0x11a0 net/bluetooth/hci_sync.c:5145 #2: ffffffff8fdfc468 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1977 [inline] #2: ffffffff8fdfc468 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592 2 locks held by syz.4.1034/8747: #0: ffffffff8fc90548 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8fc90548 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3e/0x1b0 drivers/net/tun.c:3516 #1: ffffffff8e93ecb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:296 [inline] #1: ffffffff8e93ecb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:969 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc3-next-20240816-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111