INFO: task hung in nfsd_nl_listener_get_doit

Status: upstream: reported on 2024/06/15 10:39
Subsystems: nfs
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+4207adf14e7c0981d28d@syzkaller.appspotmail.com
First crash: 862d, last: 12h14m
▶ ▼ ✨ AI Jobs (4)
ID Workflow Result Correct Bug Created Started Finished Revision
3be694e9 repro-c Reproduced: ✅ ❓ INFO: task hung in nfsd_nl_listener_get_doit 2026/08/05 15:58 2026/08/05 17:06 2026/08/05 19:17 e33390b8
3c478234 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task hung in nfsd_nl_listener_get_doit 2026/06/01 04:33 2026/06/01 04:33 2026/06/01 05:25 6b4a8443
d2e82c30 assessment-security 💥 INFO: task hung in nfsd_nl_listener_get_doit 2026/05/15 10:21 2026/05/15 10:21 2026/05/15 10:21 9cd3beaa
6f93eda4 repro ❓ INFO: task hung in nfsd_nl_listener_get_doit 2026/03/07 10:57 2026/03/07 10:57 2026/03/07 11:06 31e9c887
▶ ▼ Discussions (5)
Title Replies (including bot) Last reply
[syzbot] Monthly nfs report (Jul 2025) 0 (1) 2025/07/04 12:38
[syzbot] Monthly nfs report (Jun 2025) 0 (1) 2025/06/03 09:38
[syzbot] [nfs?] INFO: task hung in nfsd_nl_listener_get_doit 5 (7) 2024/06/17 17:21
Re: [syzbot] [nfs?] INFO: task hung in nfsd_nl_listener_get_doit 1 (1) 2024/06/17 15:45
Re: [syzbot] [nfs?] INFO: task hung in nfsd_nl_listener_get_doit 1 (1) 2024/06/17 15:00
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/07 17:06 42m nogikh@google.com upstream no crash log

Sample crash report:
INFO: task syz.2.2073:14171 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2073      state:D stack:27200 pid:14171 tgid:14165 ppid:12546  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2197
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
 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: 0033:0x7f3cf0f9e159
RSP: 002b:00007f3cf1e06028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3cf1226090 RCX: 00007f3cf0f9e159
RDX: 0000000000000004 RSI: 0000200000000080 RDI: 0000000000000007
RBP: 00007f3cf103506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3cf1226128 R14: 00007f3cf1226090 R15: 00007ffe64ce0078
 </TASK>
INFO: task syz.2.2073:14175 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2073      state:D stack:27200 pid:14175 tgid:14165 ppid:12546  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x17db/0x58f0 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821
 nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2197
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2575
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1338 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1364
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1919
 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: 0033:0x7f3cf0f9e159
RSP: 002b:00007f3cf1de5028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3cf1226180 RCX: 00007f3cf0f9e159
RDX: 0000000000000004 RSI: 0000200000000080 RDI: 0000000000000007
RBP: 00007f3cf103506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3cf1226218 R14: 00007f3cf1226180 R15: 00007ffe64ce0078
 </TASK>

Showing all locks held in the system:
locks held by pr/ttyS0/16: 2, last CPU#0:
 #0: ffffffff8ec364d8 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8ec364d8 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
 #0: ffffffff8ec364d8 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
 #1: ffffffff9ad432d8 (&port_lock_key){-.-.}-{3:3}, at: __uart_port_lock_irqsave include/linux/serial_core.h:613 [inline]
 #1: ffffffff9ad432d8 (&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#1:
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5365: 2, on CPU#0:
 #0: ffff888034ffb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5598: 2, last CPU#1:
 #0: ffff88803376e540 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff88803376e540 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:290
locks held by kworker/0:5/5746: 2, on CPU#0:
 #0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801b06b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc9000417fc40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000417fc40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000417fc40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc9000417fc40 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
locks held by syz-executor/7849: 2, last CPU#1:
 #0: ffff88807d128460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:750
locks held by syz.0.1603/12099: 2, on CPU#0:
 #0: ffff8880661840e8 (&type->s_umount_key#126){+.+.}-{4:4}, at: __super_lock fs/super.c:60 [inline]
 #0: ffff8880661840e8 (&type->s_umount_key#126){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:75 [inline]
 #0: ffff8880661840e8 (&type->s_umount_key#126){+.+.}-{4:4}, at: deactivate_super+0xac/0xe0 fs/super.c:613
 #1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x4e/0xd0 fs/nfsd/nfssvc.c:582
locks held by syz.2.2073/14171: 2, on CPU#0:
 #0: ffffffff902c5e08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2197
locks held by syz.2.2073/14175: 2, on CPU#0:
 #0: ffffffff902c5e08 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8f09f7c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2197
locks held by kworker/u8:0/14374: 8, last CPU#1:
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff88801c2ce140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc900040ffc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc900040ffc40 (net_cleanup_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc900040ffc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc900040ffc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffffffff90246448 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:677
 #3: ffff88807adeb128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #3: ffff88807adeb128 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
 #3: ffff88807adeb128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:575
 #4: ffff888029205258 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:308 [inline]
 #4: ffff888029205258 (&devlink->lock_key#12){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
 #4: ffff888029205258 (&devlink->lock_key#12){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:575
 #5: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800 drivers/net/netdevsim/netdev.c:1193
 #6: ffff888052a8ce70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2861 [inline]
 #6: ffff888052a8ce70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
 #6: ffff888052a8ce70 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x11d4/0x2140 net/core/dev.c:12515
 #7: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #7: ffffffff8ed62c68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:966
locks held by syz-executor/15267: 7, on CPU#0:
 #0: ffff888033f06460 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #0: ffff888033f06460 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:683
 #1: ffff888054004880 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:336
 #2: ffff888028cbf2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline]
 #2: ffff888028cbf2d8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:337
 #3: ffffffff8facc180 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x6d0 drivers/net/netdevsim/bus.c:184
 #4: ffff88802a37c128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff88802a37c128 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073
 #5: ffff88807a620258 (&devlink->lock_key#14){+.+.}-{4:4}, at: nsim_drv_probe+0xfb/0xbb0 drivers/net/netdevsim/dev.c:1583
 #6: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline]
 #6: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2128
locks held by syz-executor/15384: 2, on CPU#1:
 #0: ffffffff8f9bbaa8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8f9bbaa8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8f9bbaa8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:595
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline]
 #1: ffffffff90254cc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4219
locks held by dhcpcd-run-hook/15642: 3, last CPU#1:
 #0: ffff8880312fd308 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:5957 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:5991 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: do_fault mm/memory.c:6134 [inline]
 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: do_pte_missing+0x140c/0x34b0 mm/memory.c:4700
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: filemap_map_pages+0x1d1/0x2170 mm/filemap.c:3921

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: pr/ttyS0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 5e 83 54 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 7f 86 c4 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 05 d9 9c fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001578b8 EFLAGS: 00000002
RAX: 1ffffffff35a8600 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff85736780 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9ad43300 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124cc8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe5597bb7e8 CR3: 00000000422ce000 CR4: 0000000000350ef0
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+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
 </TASK>

Crashes (1817):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/30 22:47 upstream 551c722f4080 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nfsd_nl_listener_get_doit
2026/09/15 19:14 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in nfsd_nl_listener_get_doit
2026/09/12 15:52 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nfsd_nl_listener_get_doit
2026/09/12 07:56 upstream 5225b8eec4c9 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in nfsd_nl_listener_get_doit
2026/09/08 23:11 upstream 5acbae5f7eb3 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2026/09/05 05:26 upstream 654ae5d73c05 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in nfsd_nl_listener_get_doit
2026/08/29 00:07 upstream c20313e98b04 bcbc8ceb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nfsd_nl_listener_get_doit
2026/08/26 22:44 upstream 502d45774af0 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in nfsd_nl_listener_get_doit
2026/08/23 14:56 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2026/08/22 15:40 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2026/08/21 01:33 upstream 9d2ed026f031 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2026/07/29 17:39 upstream fc02acf6ac0c cb1587ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in nfsd_nl_listener_get_doit
2026/06/01 01:59 upstream 174914ea5513 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2026/05/14 14:25 upstream e1914add2799 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2026/03/04 22:56 upstream ecc64d2dc9ff e6b6b96b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: task hung in nfsd_nl_listener_get_doit
2024/06/12 23:32 upstream cea2a26553ac 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nfsd_nl_listener_get_doit
2024/06/11 07:12 upstream 83a7eefedc9b 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in nfsd_nl_listener_get_doit
2024/06/04 08:01 upstream 2ab795141095 a1feae05 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in nfsd_nl_listener_get_doit
2026/10/04 20:59 net 6dc989ea46b9 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/10/02 04:47 net e23a64eb2443 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/10/01 07:01 net 3cdeaef1754a 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/30 20:15 net 2e7ea988a032 892a21ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/27 06:03 net a7bfaba4823e a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/27 01:59 net a7bfaba4823e a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/26 21:46 net a7bfaba4823e a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/23 21:30 net 9c572a83037a 0a1606bc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/22 20:48 net 23d42b9a3bcd 3e2106e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/20 03:46 net c82b797abe66 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/18 11:42 net 3b95a04eb5f9 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/16 21:55 net ceac0de741bf 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/10 17:14 net 7f26a5e8040b 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/10 14:10 net 7f26a5e8040b 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/10 06:42 net a401a9d547c5 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/08 18:46 net e0554c6276da 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/08/25 03:10 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_listener_get_doit
2026/08/15 06:10 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_listener_get_doit
2026/08/11 10:06 net cef51860becd 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/10/03 16:06 net-next cfb7793d1bc0 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/10/03 03:32 net-next 071876fd5048 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/10/02 12:24 net-next eb0c18404c89 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/10/02 08:16 net-next eb0c18404c89 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/28 07:02 net-next 014d795c7383 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/27 23:37 net-next 014d795c7383 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/27 21:47 net-next 014d795c7383 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/27 11:48 net-next 014d795c7383 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/25 12:10 net-next 42a9fb3382fc f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/25 10:58 net-next 42a9fb3382fc f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/21 01:26 net-next a4e22e9253e7 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/20 20:42 net-next a4e22e9253e7 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/20 07:45 net-next a4e22e9253e7 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/19 15:23 net-next e3bfd25626b4 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/19 11:06 net-next e3bfd25626b4 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/18 02:48 net-next 26ee8cd69d46 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/17 15:45 net-next 7bc21b740291 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/16 13:43 net-next b8e9e7d82e7e 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/15 18:20 net-next 0019aa65bbc6 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/15 07:55 net-next 0019aa65bbc6 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/03 06:01 net-next d0ec95a8a4e7 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/08/30 01:09 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_listener_get_doit
2026/09/23 04:43 linux-next 9d80aa4617b3 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in nfsd_nl_listener_get_doit
2026/09/22 16:08 linux-next a8c591ed6b67 3e2106e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in nfsd_nl_listener_get_doit
* Struck through repros no longer work on HEAD.