INFO: task jfsCommit:121 blocked in I/O wait for more than 143 seconds. Not Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jfsCommit state:D stack:27656 pid:121 tgid:121 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1b4d/0x59e0 kernel/sched/core.c:7240 __schedule_loop kernel/sched/core.c:7317 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7332 io_schedule+0x7f/0xd0 kernel/sched/core.c:8160 __lock_metapage fs/jfs/jfs_metapage.c:52 [inline] lock_metapage+0x1fe/0x400 fs/jfs/jfs_metapage.c:66 __get_metapage+0x47a/0xdf0 fs/jfs/jfs_metapage.c:749 diIAGRead+0xce/0x140 fs/jfs/jfs_imap.c:2672 diFree+0x9dc/0x2d00 fs/jfs/jfs_imap.c:959 jfs_evict_inode+0x324/0x430 fs/jfs/inode.c:162 evict+0x624/0xb50 fs/inode.c:822 txLazyCommit fs/jfs/jfs_txnmgr.c:2666 [inline] jfs_lazycommit+0x44c/0xac0 fs/jfs/jfs_txnmgr.c:2735 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: locks held by kworker/u8:1/13: 4, last CPU#1: #0: ffff88801f6f2140 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801f6f2140 ((wq_completion)writeback){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801f6f2140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801f6f2140 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffff888034ffc0e8 (&type->s_umount_key#34){++++}-{4:4}, at: super_trylock_shared+0x23/0xf0 fs/super.c:688 #3: ffff888034ffac98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff888034ffac98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1887 [inline] #3: ffff888034ffac98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x205/0x3b0 fs/ext4/inode.c:3031 locks held by khungtaskd/32: 1, last CPU#0: #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837 locks held by jfsCommit/120: 2, on CPU#0: #0: ffff88803dfe8910 (&(imap->im_aglock[index])){+.+.}-{4:4}, at: diFree+0x2ee/0x2d00 fs/jfs/jfs_imap.c:889 #1: ffff888057b412e0 (&jfs_ip->rdwrlock/1){.+.+}-{4:4}, at: diFree+0x30c/0x2d00 fs/jfs/jfs_imap.c:894 locks held by jfsCommit/121: 2, on CPU#0: #0: ffff888037210910 (&(imap->im_aglock[index])){+.+.}-{4:4}, at: diFree+0x2ee/0x2d00 fs/jfs/jfs_imap.c:889 #1: ffff88804fa147f0 (&jfs_ip->rdwrlock/1){.+.+}-{4:4}, at: diFree+0x30c/0x2d00 fs/jfs/jfs_imap.c:894 locks held by kworker/u8:6/147: 4, last CPU#1: #0: ffff888032b87940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff888032b87940 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff888032b87940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff888032b87940 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90002e47c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90002e47c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90002e47c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90002e47c40 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffff88803d8fa1c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xd4/0xfc0 net/batman-adv/bat_iv_ogm.c:907 #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:775 [inline] #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:853 [inline] #3: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule+0x41f/0xfc0 net/batman-adv/bat_iv_ogm.c:908 locks held by kworker/u8:8/1149: 4, last CPU#1: #0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801c296140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90004e8fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004e8fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004e8fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90004e8fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffffffff9002e368 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677 #3: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x28e/0x8d0 net/core/net_namespace.c:249 locks held by kworker/u8:11/3304: 2, on CPU#1: #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc9000e577c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000e577c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000e577c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc9000e577c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 locks held by getty/5374: 2, on CPU#0: #0: ffff8880350530a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor/5615: 2, on CPU#1: #0: ffff88807d1980e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff88807d1980e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline] #0: ffff88807d1980e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:631 #1: ffffffff8f006c40 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xad/0x530 fs/jfs/jfs_logmgr.c:1441 locks held by kworker/1:5/5746: 10, last CPU#1: #0: ffff8880226cbd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff8880226cbd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff8880226cbd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff8880226cbd40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90004537c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90004537c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90004537c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90004537c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffff888029d901d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff888029d901d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5912 #3: ffff8880295d61d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff8880295d61d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2341 #4: ffff88807fadb1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88807fadb1a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88807fadb1a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffff88807b8ac0d8 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x32/0x730 drivers/scsi/hosts.c:169 #6: ffff88801db8e3c0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #6: ffff88801db8e3c0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #6: ffff88801db8e3c0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #7: ffff88807b8ac3b0 (&set->update_nr_hwq_lock){++++}-{4:4}, at: del_gendisk+0xdf/0x160 block/genhd.c:818 #8: ffff88802b0e2f28 (&q->q_usage_counter(queue)#53){++++}-{0:0}, at: del_gendisk+0xe7/0x160 block/genhd.c:819 #9: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #9: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #9: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4345 [inline] #9: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x101/0xca0 kernel/workqueue.c:4403 locks held by udevd/6000: 1, last CPU#1: #0: ffff8880350edcf8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline] #0: ffff8880350edcf8 (&mm->mmap_lock){++++}-{4:4}, at: do_mprotect_pkey+0x25c/0xd10 mm/mprotect.c:902 locks held by syz-executor/7017: 1, on CPU#1: #0: ffff888021fdc0e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888021fdc0e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline] #0: ffff888021fdc0e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:631 locks held by syz-executor/8023: 1, on CPU#1: #0: ffff8880544d80e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880544d80e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline] #0: ffff8880544d80e8 (&type->s_umount_key#83){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:631 locks held by syz-executor/8870: 2, on CPU#0: #0: ffffffff9002e368 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4e2/0x720 net/core/net_namespace.c:579 #1: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:149 [inline] #1: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11595 locks held by syz.0.735/8910: 1, last CPU#1: #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #0: ffffffff8eb5c8a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by syz.5.736/8900: 3, last CPU#1: #0: ffff88805544e0e8 (&type->s_umount_key#55/1){+.+.}-{4:4}, at: alloc_super fs/super.c:365 [inline] #0: ffff88805544e0e8 (&type->s_umount_key#55/1){+.+.}-{4:4}, at: sget_fc+0x97c/0x1a40 fs/super.c:889 #1: ffffffff8ec88860 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:316 [inline] #1: ffffffff8ec88860 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4636 [inline] #1: ffffffff8ec88860 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4974 [inline] #1: ffffffff8ec88860 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_cache_noprof+0x61/0x600 mm/slub.c:5559 #2: ffffffff8ec9e260 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4392 locks held by syz.7.738/8917: 2, on CPU#1: #0: ffffffff905947b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff905947b0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff905947b0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595 #1: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #1: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214 locks held by syz.7.738/8919: 1, on CPU#1: #0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3da/0x1e70 drivers/net/tun.c:3218 locks held by syz.7.738/8921: 1, on CPU#1: #0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7138 locks held by syz.7.738/8922: 1, on CPU#1: #0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #0: ffffffff9003cf40 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214 locks held by dhcpcd-run-hook/8918: 1, last CPU#1: #0: ffff88805a700808 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 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: 16 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409 Code: e8 2e c3 5a fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 3f 31 c9 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 ca 12 72 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001578b8 EFLAGS: 00000002 RAX: 1ffffffff3560100 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff856ce650 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9ab00b80 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812500a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c399afe CR3: 0000000066920000 CR4: 00000000003526f0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2013 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline] __serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3345 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline] __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline] serial8250_console_write+0xaa1/0x1200 drivers/tty/serial/8250/8250_port.c:3493 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline] nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245