INFO: task syz.4.83:6072 blocked for more than 156 seconds. Not tainted 6.12.0-rc2-syzkaller-00074-gd3d1556696c1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.83 state:D stack:20888 pid:6072 tgid:6071 ppid:5653 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1843/0x4ae0 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 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 __flush_work+0xa37/0xc50 kernel/workqueue.c:4217 flush_work kernel/workqueue.c:4238 [inline] flush_delayed_work+0x169/0x1c0 kernel/workqueue.c:4260 invalidate_dquots fs/quota/dquot.c:577 [inline] dquot_disable+0x7a7/0x1cd0 fs/quota/dquot.c:2295 ocfs2_disable_quotas+0xf3/0x210 fs/ocfs2/super.c:963 ocfs2_dismount_volume+0x1ad/0x8f0 fs/ocfs2/super.c:1870 generic_shutdown_super+0x139/0x2d0 fs/super.c:642 kill_block_super+0x44/0x90 fs/super.c:1696 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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [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+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f502057dff9 RSP: 002b:00007f50212d4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: 0000000000000000 RBX: 00007f5020735f80 RCX: 00007f502057dff9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007f50205f0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5020735f80 R15: 00007ffde50ceba8 Showing all locks held in the system: 3 locks held by kworker/u8:0/11: #0: ffff88801ac89148 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3204 [inline] , at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000107d00 ( (linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] (linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf8c8 ( rtnl_mutex ){+.+.}-{3:3} , at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 3 locks held by kworker/u8:1/12: #0: ffff88814bf1d148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3204 [inline] , at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000117d00 ( (work_completion)(&(&ifa->dad_work)->work) ){+.+.}-{0:0} , at: process_one_work kernel/workqueue.c:3205 [inline] , at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf8c8 ( rtnl_mutex ){+.+.}-{3:3} , at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 ( rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] , at: rcu_read_lock include/linux/rcupdate.h:849 [inline] , at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 5 locks held by kworker/u8:2/35: #0: ffff88801baeb148 ((wq_completion)netns ){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] ){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000ab7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcb2dd0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffffffff8fcbf8c8 (rtnl_mutex){+.+.}-{3:3}, at: cleanup_net+0x6af/0xcc0 net/core/net_namespace.c:616 #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #4: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 2 locks held by kworker/u8:3/51: 4 locks held by kworker/u8:5/994: 12 locks held by kworker/u8:6/1593: 1 lock held by dhcpcd/4887: #0: ffffffff8fcbf8c8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1aa0 net/ipv4/devinet.c:1097 2 locks held by getty/4982: #0: ffff88802e5040a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002efe2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:6/5305: #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90004317d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90004317d00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcbf8c8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by syz-executor/5878: #0: ffff88802de700e0 ( &type->s_umount_key #31 ){++++}-{3:3} , at: __super_lock fs/super.c:56 [inline] , at: __super_lock_excl fs/super.c:71 [inline] , at: deactivate_super+0xb5/0xf0 fs/super.c:505 #1: ffff888024fc87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:388 [inline] ffff888024fc87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2797 1 lock held by syz.4.83/6072: #0: ffff888030b5a0e0 (&type->s_umount_key#82){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] (&type->s_umount_key#82){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] (&type->s_umount_key#82){++++}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505 1 lock held by syz-executor/6818: #0: ffffffff8fcbf8c8 (rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:79 [inline] , at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/6819: #0: ffffffff8fcbf8c8 (rtnl_mutex ){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] ){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 1 lock held by syz-executor/6823: #0: ffffffff8fcbf8c8 (rtnl_mutex ){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] ){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 7 locks held by syz-executor/6869: #0: ffff88802e2c4420 (sb_writers #8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] #8){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff88807a9ae888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888144f25c38 (kn->active#49){.+.+}-{0:0} , at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f55d9c8 ( nsim_bus_dev_list_lock ){+.+.}-{3:3} , at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88807871f0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] ffff88807871f0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] ffff88807871f0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88806cbf0250 ( &devlink->lock_key #20 ){+.+.}-{3:3} , at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1672 #6: ffffffff8fcbf8c8 ( rtnl_mutex){+.+.}-{3:3} , at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 4 locks held by syz-executor/6881: #0: ffff88802e2c4420 (sb_writers#8 ){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline] ){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679 #1: ffff88806b69c888 (&of->mutex){+.+.}-{3:3} , at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888144f25c38 (kn->active#49){.+.+}-{0:0} , at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f55d9c8 (nsim_bus_dev_list_lock ){+.+.}-{3:3}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 1 lock held by syz-executor/6992: #0: ffffffff8fcbf8c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fcbf8c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x6e6/0xcf0 net/core/rtnetlink.c:6643 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00074-gd3d1556696c1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1593 Comm: kworker/u8:6 Not tainted 6.12.0-rc2-syzkaller-00074-gd3d1556696c1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound quota_release_workfn RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:406 Code: 00 e4 53 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 31 71 ba fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c RSP: 0018:ffffc900043f7078 EFLAGS: 00000002 RAX: 1ffffffff34db900 RBX: ffffffff9a6dcc00 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000000 R08: ffffffff854102f6 R09: 1ffff1100490b046 R10: dffffc0000000000 R11: ffffffff854102b0 R12: dffffc0000000000 R13: ffffffff9a3d7ef0 R14: 00000000000003fd R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8750a7f866 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr drivers/tty/serial/8250/8250_port.c:2068 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3315 [inline] serial8250_console_write+0x1373/0x1ed0 drivers/tty/serial/8250/8250_port.c:3393 console_emit_next_record kernel/printk/printk.c:3092 [inline] console_flush_all+0x869/0xeb0 kernel/printk/printk.c:3180 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 ocfs2_handle_error+0x86/0x250 fs/ocfs2/super.c:2526 __ocfs2_abort+0x1c1/0x230 fs/ocfs2/super.c:2600 ocfs2_start_trans+0x621/0x700 fs/ocfs2/journal.c:360 ocfs2_release_dquot+0x474/0xc40 fs/ocfs2/quota_global.c:761 quota_release_workfn+0x39f/0x650 fs/quota/dquot.c:839 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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