INFO: task hung in nfsd_nl_unlock_filesystem_doit

Status: upstream: reported on 2026/08/28 07:35
Subsystems: nfs
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+0093d3ab8d8eb2fdde82@syzkaller.appspotmail.com
First crash: 53d, last: 19h35m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
d9b93f35 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: task hung in nfsd_nl_unlock_filesystem_doit 2026/07/15 00:06 2026/07/15 00:06 2026/07/15 00:56 2130f682
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [nfs?] INFO: task hung in nfsd_nl_unlock_filesystem_doit 0 (1) 2026/08/28 07:35

Sample crash report:
INFO: task syz.5.260:6966 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.260       state:D stack:27656 pid:6966  tgid:6965  ppid:6395   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0xdd/0x2c0 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+0xccb/0x1bd0 kernel/locking/mutex.c:821
 nfsd_nl_unlock_filesystem_doit+0x203/0x410 fs/nfsd/nfsctl.c:2677
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 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+0x585/0x850 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:800 [inline]
 __sock_sendmsg net/socket.c:815 [inline]
 ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2713
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2767
 __sys_sendmsg+0x160/0x210 net/socket.c:2799
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce8bd9e159
RSP: 002b:00007fce8cbbc028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fce8c025fa0 RCX: 00007fce8bd9e159
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000004
RBP: 00007fce8be35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fce8c026038 R14: 00007fce8c025fa0 R15: 00007ffe84592e88
 </TASK>

Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#1:
 #0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #0: ffffffff8edd8338 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x49/0x60 kernel/printk/printk.c:291
 #1: ffffffff9bc63c78 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9bc63c78 (&port_lock_key){-.-.}-{3:3}, at: univ8250_console_device_lock+0x64/0xc0 drivers/tty/serial/8250/8250_core.c:413
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6837
locks held by kworker/u8:2/43: 3, last CPU#0:
 #0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc90000b37d08 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffff888056e607a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6905 [inline]
 #2: ffff888056e607a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x92/0x550 net/wireless/core.c:527
locks held by kworker/u8:4/59: 2, on CPU#0:
 #0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc9000201fd08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
locks held by kworker/u8:8/1147: 6, on CPU#1:
 #0: ffff88801d2d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc90004dd7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffffffff90cb6a48 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:677
 #3: ffffffff90ccf540 (rtnl_mutex){+.+.}-{4:4}, at: ieee80211_unregister_hw+0x4d/0x360 net/mac80211/main.c:1710
 #4: ffff88804a8207a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6905 [inline]
 #4: ffff88804a8207a0 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: ieee80211_remove_interfaces+0xf0/0x6e0 net/mac80211/iface.c:2467
 #5: ffffffff8edf7f68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
locks held by kworker/u8:9/1291: 5, last CPU#0:
 #0: ffff88801c094140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc900058d7d08 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffffffff8ec7ca50 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:222
 #3: ffffffff8ef40280 (jump_label_mutex){+.+.}-{4:4}, at: jump_label_lock kernel/jump_label.c:27 [inline]
 #3: ffffffff8ef40280 (jump_label_mutex){+.+.}-{4:4}, at: static_key_enable_cpuslocked+0xb5/0x270 kernel/jump_label.c:207
 #4: ffffffff8ec9c340 (text_mutex){+.+.}-{4:4}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
locks held by klogd/4958: 1, last CPU#0:
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0x90/0x600 net/core/sock.c:3655
locks held by getty/5362: 2, on CPU#1:
 #0: ffff8880347c80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032262e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by sshd-session/5585: 1, last CPU#0:
 #0: ffff8880351cc378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
 #0: ffff8880351cc378 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa00 mm/mmap.c:1323
locks held by syz-executor/5591: 2, last CPU#0:
 #0: ffff88802b65a9f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff88802b65a9f8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by syz-executor/5595: 2, last CPU#0:
 #0: ffff88807da2f678 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff88807da2f678 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by syz-executor/5606: 2, on CPU#1:
 #0: ffff888026ccc0e8 (&type->s_umount_key#89){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff888026ccc0e8 (&type->s_umount_key#89){++++}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
 #0: ffff888026ccc0e8 (&type->s_umount_key#89){++++}-{4:4}, at: deactivate_super fs/super.c:631 [inline]
 #0: ffff888026ccc0e8 (&type->s_umount_key#89){++++}-{4:4}, at: deactivate_super+0xe2/0x110 fs/super.c:628
 #1: ffffffff8f287680 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:582
locks held by kworker/u8:11/6065: 4, last CPU#0:
 #0: ffff888034c7e140 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc90006ec7d08 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffff88804c7ed9c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1010 [inline]
 #2: ffff88804c7ed9c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:1005 [inline]
 #2: ffff88804c7ed9c8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_send_outstanding_bat_ogm_packet+0x50f/0x7d0 net/batman-adv/bat_iv_ogm.c:1924
 #3: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:870 [inline]
 #3: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: batadv_iv_ogm_schedule_buff+0x583/0x15d0 net/batman-adv/bat_iv_ogm.c:949
locks held by syz.1.132/6302: 2, on CPU#1:
 #0: ffffffff90d7eac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8f287680 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x1a3/0x1dc0 fs/nfsd/nfsctl.c:2057
locks held by syz-executor/6524: 2, last CPU#0:
 #0: ffff88802ddc4378 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff88802ddc4378 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x124/0xa00 mm/mmap.c:1299
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8edec060 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:290
locks held by syz.5.260/6966: 2, on CPU#1:
 #0: ffffffff90d7eac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8f287680 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_unlock_filesystem_doit+0x203/0x410 fs/nfsd/nfsctl.c:2677
locks held by syz.8.594/8394: 1, on CPU#1:
 #0: ffff888026ccc0e8 (&type->s_umount_key#89){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline]
 #0: ffff888026ccc0e8 (&type->s_umount_key#89){++++}-{4:4}, at: super_lock+0x326/0x3f0 fs/super.c:124
locks held by syz-executor/8495: 1, last CPU#0:
 #0: ffff8880351cd038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
 #0: ffff8880351cd038 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa00 mm/mmap.c:1323
locks held by syz-executor/8500: 5, last CPU#0:
 #0: ffff888031b20460 (sb_writers#8){.+.+}-{0:0}, at: ksys_write+0x12a/0x250 fs/read_write.c:739
 #1: ffff8880841d7480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x2c2/0x5f0 fs/kernfs/file.c:336
 #2: ffff88802abd0698 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff88802abd0698 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x332/0x5f0 fs/kernfs/file.c:337
 #3: ffffffff90235da0 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0xfe/0x6d0 drivers/net/netdevsim/bus.c:184
 #4: ffffffff91272200 (uevent_sock_mutex){+.+.}-{4:4}, at: uevent_net_broadcast_untagged lib/kobject_uevent.c:317 [inline]
 #4: ffffffff91272200 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
 #4: ffffffff91272200 (uevent_sock_mutex){+.+.}-{4:4}, at: kobject_uevent_env+0xba8/0x18b0 lib/kobject_uevent.c:611
locks held by syz-executor/8524: 1, last CPU#0:
 #0: ffff88807c37b6b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline]
 #0: ffff88807c37b6b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x22c/0xa00 mm/mmap.c:1323
locks held by syz.0.644/8601: 3, on CPU#0:
 #0: ffffffff90d7eac8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffff8880837476e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0x150/0x990 net/netlink/af_netlink.c:2410
 #2: ffffffff8f287680 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_svc_export_get_reqs_dumpit+0x112/0xd10 fs/nfsd/export.c:674
locks held by syz.6.648/8630: 1, last CPU#1:
 #0: ffff88802b65e9b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #0: ffff88802b65e9b8 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
locks held by syz.6.648/8631: 1, on CPU#0:
 #0: ffff88802b65e9b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:609 [inline]
 #0: ffff88802b65e9b8 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:450 [inline]
 #0: ffff88802b65e9b8 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x160/0x6f0 mm/mmap_lock.c:501
locks held by syz.6.648/8633: 1, on CPU#1:
 #0: ffffffff90ccf540 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90ccf540 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:7138
locks held by syz.6.648/8634: 1, on CPU#1:
 #0: ffffffff90ccf540 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff90ccf540 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:7138
locks held by modprobe/8632: 2, last CPU#0:
 #0: ffff88802b65f678 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #0: ffff88802b65f678 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x1f5/0x470 mm/util.c:579
 #1: ffff888034237598 (&anon_vma->rwsem){++++}-{4:4}, at: anon_vma_lock_read mm/internal.h:310 [inline]
 #1: ffff888034237598 (&anon_vma->rwsem){++++}-{4:4}, at: validate_mm+0x1f1/0x4e0 mm/vma.c:724

=============================================

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 08/05/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
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 08/05/2026
RIP: 0010:io_serial_in+0x87/0xb0 drivers/tty/serial/8250/8250_port.c:410
Code: 07 5c fc 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1a 66 03 5d 40 89 da ec <5b> 0f b6 c0 5d 41 5c c3 cc cc cc cc e8 48 1a cf fc eb a2 e8 d1 1a
RSP: 0018:ffffc90000157958 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: ffffffff85afe8d0 RDI: ffffffff9bc63ca0
RBP: ffffffff9bc63c60 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000000 R11: 205d323354202020 R12: 0000000000000000
R13: 0000000000000020 R14: fffffbfff378c7e9 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888123c61000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3f2784dd58 CR3: 0000000061d88000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:128 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
 wait_for_lsr+0x13a/0x210 drivers/tty/serial/8250/8250_port.c:2013
 serial8250_fifo_wait_for_lsr_thre+0x5f/0xd0 drivers/tty/serial/8250/8250_port.c:3270
 __serial8250_console_fifo_write+0xa5/0x290 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+0xf46/0x1330 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0x8f7/0xa70 kernel/printk/nbcon.c:1070
 nbcon_emit_one+0x1a8/0x2b0 kernel/printk/nbcon.c:1157
 nbcon_kthread_func+0x613/0x7d0 kernel/printk/nbcon.c:1271
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (42):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/03 21:16 upstream 940de590b839 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/26 18:05 upstream 45c13f3f9e3b a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/26 13:46 upstream 45c13f3f9e3b 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/25 09:51 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/25 02:09 net 3e995a30b9e3 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/18 05:43 net ad27ed7d2309 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/18 03:06 net ad27ed7d2309 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/17 23:37 net ad27ed7d2309 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/16 06:37 net 24ef02f934ee 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/13 18:45 net 9006c116dd11 a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/11 22:01 net b37971686ec5 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/11 20:49 net b37971686ec5 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/11 15:54 net b37971686ec5 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/27 23:37 net 53658c6f3682 4cb2b096 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/25 05:43 net 78f75d632f74 05b26a28 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/22 15:13 net ba712ecfd942 b561ce9c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/30 00:03 net-next 1b78070aaef6 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/29 15:31 net-next 1b78070aaef6 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/29 14:09 net-next 1b78070aaef6 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 12:04 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 11:30 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 10:41 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 07:16 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 06:16 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 03:11 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 02:53 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/24 00:58 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/23 15:14 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/23 13:54 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/23 12:14 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/23 04:50 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/23 00:48 net-next 91ec20351349 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/17 09:56 net-next e6a5d573d24c 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/11 22:46 net-next b54074ffb813 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/11 20:19 net-next b54074ffb813 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/11 18:08 net-next b54074ffb813 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/24 13:27 net-next 89d8006259b8 544adce9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/22 00:55 net-next abc435224e87 7c5de9c3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/08/30 00:57 linux-next e30626823a40 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/25 07:47 linux-next cc2b5f627e8c 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/13 22:44 linux-next 49362394dad7 2130f682 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
2026/07/13 06:06 linux-next bee763d5f341 d78ea535 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in nfsd_nl_unlock_filesystem_doit
* Struck through repros no longer work on HEAD.