INFO: task syz.0.1330:10761 blocked for m INFO: task syz.0.1330:10761 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.1330 state:D stack:26976 pid:10761 tgid:10760 ppid:5614 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7270 __schedule_loop kernel/sched/core.c:7347 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7362 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7419 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 nfsd_nl_expkey_get_reqs_dumpit+0xfd/0xd40 fs/nfsd/export.c:347 genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026 netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331 __netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446 genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075 genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline] genl_rcv_msg+0x5e1/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2713 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767 __sys_sendmsg net/socket.c:2799 [inline] __do_sys_sendmsg net/socket.c:2804 [inline] __se_sys_sendmsg net/socket.c:2802 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fadf199e159 RSP: 002b:00007fadf28e4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fadf1c25fa0 RCX: 00007fadf199e159 RDX: 0000000004044810 RSI: 0000200000000180 RDI: 0000000000000004 RBP: 00007fadf1a3503b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fadf1c26038 R14: 00007fadf1c25fa0 R15: 00007ffd2f1fccb8 Showing all locks held in the system: locks held by kworker/u8:0/12: 2, last CPU#1: #0: ffff88802ca1d140 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88802ca1d140 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88802ca1d140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88802ca1d140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90000117c40 ((work_completion)(&(&bat_priv->tt.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 locks held by pr/ttyS0/16: 2, last CPU#1: #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline] #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline] #0: ffffffff8ec362b8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291 #1: ffffffff9ad32098 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline] #1: ffffffff9ad32098 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x67/0xc0 drivers/tty/serial/8250/8250_core.c:413 locks held by khungtaskd/32: 1, last CPU#0: #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837 locks held by kworker/u8:6/509: 3, last CPU#1: #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90003ca7c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90003ca7c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90003ca7c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90003ca7c40 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffff8880422b07a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6906 [inline] #2: ffff8880422b07a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xb4/0x420 net/wireless/core.c:527 locks held by kworker/u8:7/1120: 3, last CPU#1: #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801b0ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000541fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000541fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000541fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000541fc40 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffff88802afc6258 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x57/0xb40 drivers/net/netdevsim/dev.c:834 locks held by udevd/4985: 2, last CPU#1: #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_path_perm+0x251/0x560 security/tomoyo/file.c:826 #1: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:749 locks held by dhcpcd/5280: 1, last CPU#1: #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #0: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 locks held by getty/5374: 2, on CPU#1: #0: ffff888035f0d0a0 (&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/5626: 4, last CPU#0: #0: ffffffff8ee35c10 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline] #0: ffffffff8ee35c10 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x10f/0x480 kernel/fork.c:1595 #1: ffff88807f4b29f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline] #1: ffff88807f4b29f8 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716 #2: ffff88801b09c378 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline] #2: ffff88801b09c378 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723 #3: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #3: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8ed5c6e0 (rcu_read_lock){....}-{1:3}, at: __page_table_check_zero+0x6c/0x430 mm/page_table_check.c:138 locks held by kworker/u8:17/6272: 7, on CPU#1: #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801c2d6140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000668fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000668fc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000668fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000668fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffffffff902424e8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677 #3: ffff88802cea0128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff88802cea0128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff88802cea0128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:575 #4: ffff8880217d7258 (&devlink->lock_key){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:308 [inline] #4: ffff8880217d7258 (&devlink->lock_key){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff8880217d7258 (&devlink->lock_key){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:575 #5: ffffffff90250d40 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1193 #6: ffff888023710e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline] #6: ffff888023710e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #6: ffff888023710e70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x11d4/0x2140 net/core/dev.c:12504 locks held by syz.2.1236/10405: 2, on CPU#0: #0: ffffffff902c1be8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f09e400 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x53d/0x1ab0 fs/nfsd/nfsctl.c:2057 locks held by syz.0.1330/10761: 3, on CPU#0: #0: ffffffff902c1be8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff8880548056e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2410 #2: ffffffff8f09e400 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_expkey_get_reqs_dumpit+0xfd/0xd40 fs/nfsd/export.c:347 locks held by syz-executor/10849: 1, last CPU#0: #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline] #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline] #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline] #0: ffffffff8f4ef978 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_check_open_permission+0x1d3/0x470 security/tomoyo/file.c:772 locks held by kworker/u8:18/11986: 4, last CPU#1: #0: ffff88801235e140 ((wq_completion)wg-kex-wg0#3){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88801235e140 ((wq_completion)wg-kex-wg0#3){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88801235e140 ((wq_completion)wg-kex-wg0#3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88801235e140 ((wq_completion)wg-kex-wg0#3){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc9000ff7fc40 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc9000ff7fc40 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc9000ff7fc40 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc9000ff7fc40 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #2: ffff888077369440 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x12e/0x810 drivers/net/wireguard/noise.c:529 #3: ffff88807886c888 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x13f/0x810 drivers/net/wireguard/noise.c:530 locks held by syz.7.1704/12463: 2, on CPU#1: #0: ffffffff902c1be8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff90250d40 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5e/0x890 net/wireless/nl80211.c:19477 locks held by syz.7.1704/12466: 2, on CPU#1: #0: ffff888077eb30e0 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3e/0x100 net/netfilter/nf_tables_api.c:11530 #1: ffffffff8ed62aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8ed62aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:966 locks held by dhcpcd/12464: 2, on CPU#1: #0: ffff888056e18800 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff888056e18800 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:734 #1: ffffffff8ed62aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8ed62aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:966 locks held by syz.4.1705/12467: 1, on CPU#1: #0: ffff888078ca50e0 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3e/0x100 net/netfilter/nf_tables_api.c:11530 ============================================= 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 4e b3 55 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 9f 7c c5 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 9a 10 75 06 cc 44 89 f9 80 e1 07 RSP: 0018:ffffc900001578b8 EFLAGS: 00000002 RAX: 1ffffffff35a6400 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: ffffffff85720780 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9ad320c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124dd9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea989ed158 CR3: 0000000079272000 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