INFO: task syz.3.2109:14531 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.3.2109 state:D stack:25928 pid:14531 tgid:14526 ppid:5808 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
__mutex_lock_common kernel/locking/mutex.c:712 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:806
nfsd_nl_threads_set_doit+0x6c1/0xc00 fs/nfsd/nfsctl.c:1607
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:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698
___sys_sendmsg+0x190/0x1e0 net/socket.c:2752
__sys_sendmsg+0x170/0x220 net/socket.c:2784
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8a3959c819
RSP: 002b:00007f8a3a3ca028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8a39815fa0 RCX: 00007f8a3959c819
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000007
RBP: 00007f8a39632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8a39816038 R14: 00007f8a39815fa0 R15: 00007ffd4551c878
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/48:
#0: ffff8880342cd940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90000b97d08 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11f/0x1360 net/ipv6/addrconf.c:4206
1 lock held by dhcpcd/5477:
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x49c/0x1bb0 net/ipv6/addrconf.c:5039
2 locks held by getty/5571:
#0: ffff88803519e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
2 locks held by kworker/1:3/5816:
#0: ffff88813feaf140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc900024dfd08 ((work_completion)(&m->mpeg_thread)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
4 locks held by kworker/u8:7/11499:
#0: ffff88801c6d8940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90003247d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffffffff90610e28 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:673
#3: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
#3: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248
8 locks held by kworker/u8:18/11516:
#0: ffff8880b843b260 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:660 [inline]
#0: ffff8880b843b260 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:644
#1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2d69/0x6820 kernel/sched/core.c:7182
#2: ffff8880b8426358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x124/0x1d0 kernel/time/timer.c:1004
#3: ffffffff9b44fa48 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x144/0x490 lib/debugobjects.c:835
#4: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#4: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#4: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
#4: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
#5: ffff8880b84284d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline]
#5: ffff8880b84284d8 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_rearm_deferred+0xb9/0x740 kernel/time/hrtimer.c:2051
#6: ffffffff9b22ce88 (&____s->seqcount#2){----}-{0:0}, at: clockevents_program_event+0x23e/0x7e0 kernel/time/clockevents.c:360
#7: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_enqueue kernel/sched/stats.h:166 [inline]
#7: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: enqueue_task+0x1d6/0x4f0 kernel/sched/core.c:2167
3 locks held by kworker/u8:19/11519:
#0: ffff88813fe2c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90004567d08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313
3 locks held by kworker/0:5/13076:
#0: ffff88813feaf140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277
#1: ffffc90003c67d08 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278
#2: ffffffff8e7f0fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by syz.4.2047/14276:
#0: ffffffff906d7788 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec61340 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x6c1/0xc00 fs/nfsd/nfsctl.c:1607
2 locks held by syz.3.2109/14531:
#0: ffffffff906d7788 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec61340 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x6c1/0xc00 fs/nfsd/nfsctl.c:1607
3 locks held by syz-executor/15834:
#0: ffff88803ade4ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff88803ade40b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908c0e00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908c0e00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
1 lock held by syz.5.2476/15956:
1 lock held by syz-executor/16300:
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8bb/0x2380 net/core/rtnetlink.c:4107
4 locks held by syz.8.2528/16315:
#0: ffff8880742f0ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xb0 net/bluetooth/hci_core.c:500
#1: ffff8880742f00b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x35c/0x1240 net/bluetooth/hci_sync.c:5356
#2: ffffffff908c0e00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff908c0e00 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x280 net/bluetooth/hci_conn.c:2650
#3: ffff88802620c2f8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x95/0x710 net/bluetooth/l2cap_core.c:1777
2 locks held by syz.7.2529/16339:
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90629760 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3438
#1: ffffffff8e7f0fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: e6 88 02 e9 83 42 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 b0 13 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e407e00 EFLAGS: 00000242
RAX: 0000000004abf2d9 RBX: ffffffff8e4955c0 RCX: ffffffff8b97e045
RDX: 0000000000000000 RSI: ffffffff8df5460f RDI: ffffffff8c1c1380
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170867ad
R10: ffff8880b8433d6b R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90dbbe50
FS: 0000000000000000(0000) GS:ffff8881242ef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffef12b83b8 CR3: 000000000e596000 CR4: 00000000003526f0
DR0: 00000000000007ff DR1: 0000000000000001 DR2: 0000000000000005
DR3: 0000000000000010 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:762
start_kernel+0x484/0x490 init/main.c:1220
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148