INFO: task syz.1.2096:16910 blocked for more than 143 seconds.
Tainted: G U L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2096 state:D stack:28200 pid:16910 tgid:16904 ppid:5626 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x125c/0x6730 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0xdd/0x2c0 kernel/sched/core.c:7326
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821
nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
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:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2684
___sys_sendmsg+0x190/0x1e0 net/socket.c:2738
__sys_sendmsg+0x160/0x210 net/socket.c:2770
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f43a3f9ce59
RSP: 002b:00007f43a21b4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f43a4216180 RCX: 00007f43a3f9ce59
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000002
RBP: 00007f43a4032e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f43a4216218 R14: 00007f43a4216180 R15: 00007ffd5f4d3e98
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e7e5ec0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz-executor/5624:
#0: ffff8880337fe0d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880337fe0d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880337fe0d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880337fe0d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.3.622/9188:
#0: ffff8880371de0d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880371de0d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880371de0d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880371de0d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
4 locks held by kworker/0:5/11925:
2 locks held by syz.1.2096/16909:
#0: ffffffff906ed668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.1.2096/16910:
#0: ffffffff906ed668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
2 locks held by syz.6.2214/17570:
#0: ffffffff906ed668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x8c8/0x1100 fs/nfsd/nfsctl.c:1660
2 locks held by getty/17665:
#0: ffff8880373ae0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90004cfd2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/17695:
#0: ffff88807f72c0d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807f72c0d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807f72c0d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88807f72c0d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz-executor/17755:
#0: ffff88802b5460d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802b5460d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802b5460d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff88802b5460d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.7.2290/17989:
#0: ffffffff906ed668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x8c8/0x1100 fs/nfsd/nfsctl.c:1660
2 locks held by syz-executor/17995:
#0: ffff8880266c60d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff8880266c60d8 (&type->s_umount_key#54){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff8880266c60d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super fs/super.c:509 [inline]
#0: ffff8880266c60d8 (&type->s_umount_key#54){++++}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:506
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:576
2 locks held by syz.0.2367/18645:
#0: ffffffff906ed668 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec6f080 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964
1 lock held by syz-executor/18820:
#0: ffffffff9063edc0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
#0: ffffffff9063edc0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3506
3 locks held by syz.1.2415/19337:
#0: ffffffff906261c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff9063edc0 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0x90/0xc10 net/core/dev.c:13079
#2: ffffffff8e7f1968 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.1.2415/19338:
#0: ffffffff906261c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff9063edc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#1: ffffffff9063edc0 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x1c/0xf0 net/core/dev.c:2132
2 locks held by syz.2.2416/19355:
#0: ffffffff906261c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:575
#1: ffffffff9063edc0 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:4017
1 lock held by syz.4.2418/19356:
#0: ffff888055898ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:497
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G U L syzkaller #0 PREEMPT(full)
Tainted: [U]=USER, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__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:122
nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245