INFO: task syz.5.8063:10028 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.8063 state:D stack:24768 pid:10028 tgid:10025 ppid:31696 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1683
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f579a19c799
RSP: 002b:00007f579b0c4028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f579a415fa0 RCX: 00007f579a19c799
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000008
RBP: 00007f579a232bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f579a416038 R14: 00007f579a415fa0 R15: 00007ffcc93e12d8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5579:
#0: ffff888036f9a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/6190:
#0: ffff888026b3d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by udevd/6500:
#0: ffff888026b51358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
2 locks held by syz.4.7688/8151:
#0:
ffffffff8fc3ad30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea86c28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1893
2 locks held by syz.5.8063/10028:
#0: ffffffff8fc3ad30 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ea86c28 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1683
5 locks held by syz.3.9116/15092:
2 locks held by dhcpcd-run-hook/15111:
3 locks held by modprobe/15139:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 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: 14634 Comm: syz.9.9026 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:select_task_rq_fair+0x49e/0x4320 kernel/sched/fair.c:8547
Code: 48 8b 1b 4d 89 fc 48 85 db 0f 84 d8 00 00 00 48 8d 6b 3c 49 89 ef 49 c1 ef 03 43 0f b6 04 37 84 c0 0f 85 8d 00 00 00 8b 45 00 <80> 7c 24 08 00 74 0d 49 89 df 44 85 e8 75 56 e9 a9 00 00 00 a8 10
RSP: 0018:ffffc90000a08bd8 EFLAGS: 00000046
RAX: 0000000000001297 RBX: ffff88801baa9800 RCX: 0000000080010204
RDX: 00000000ad839568 RSI: ffffffff8e1620fd RDI: ffffffff8c27aa00
RBP: ffff88801baa983c R08: ffffffff81981d7e R09: ffffffff8e7602e0
R10: dffffc0000000000 R11: ffffffff81981a30 R12: 0000000000000000
R13: 0000000000000008 R14: dffffc0000000000 R15: 1ffff11003755307
FS: 00007fd709ef46c0(0000) GS:ffff888125567000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7d80242000 CR3: 000000006a60c000 CR4: 00000000003526f0
Call Trace:
select_task_rq kernel/sched/core.c:3521 [inline]
try_to_wake_up+0x4db/0x1390 kernel/sched/core.c:4230
hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:2021
__run_hrtimer kernel/time/hrtimer.c:1785 [inline]
__hrtimer_run_queues+0x53a/0xcc0 kernel/time/hrtimer.c:1849
hrtimer_interrupt+0x42b/0x1010 kernel/time/hrtimer.c:1911
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x460 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478
Code: 0f 84 44 ff ff ff e8 72 27 21 00 fb eb 44 e8 6a 27 21 00 e8 45 ce 08 0a 4d 85 f6 74 94 e8 5b 27 21 00 fb 48 c7 c7 20 27 75 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 16
RSP: 0018:ffffc900035e6d80 EFLAGS: 00000293
RAX: ffffffff81a46455 RBX: ffffffff81a462cf RCX: ffff888079de8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e752720
RBP: ffffc900035e6e30 R08: ffffffff901181b7 R09: 1ffffffff2023036
R10: dffffc0000000000 R11: fffffbfff2023037 R12: 0000000000000000
R13: 000000000000005e R14: 0000000000000200 R15: 1ffff920006bcdb4
_printk+0xdd/0x130 kernel/printk/printk.c:2504
ip_vs_schedule+0x15a7/0x1d10 net/netfilter/ipvs/ip_vs_core.c:517
udp_conn_schedule+0x359/0x750 net/netfilter/ipvs/ip_vs_proto_udp.c:78
ip_vs_try_to_schedule net/netfilter/ipvs/ip_vs_core.c:1478 [inline]
ip_vs_in_hook+0x1005/0x22d0 net/netfilter/ipvs/ip_vs_core.c:2050
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook+0x22a/0x3a0 include/linux/netfilter.h:273
__ip_local_out+0x558/0x6a0 net/ipv4/ip_output.c:120
ip_local_out net/ipv4/ip_output.c:129 [inline]
__ip_queue_xmit+0x116e/0x1be0 net/ipv4/ip_output.c:534
l2tp_xmit_queue net/l2tp/l2tp_core.c:1219 [inline]
l2tp_xmit_core net/l2tp/l2tp_core.c:1311 [inline]
l2tp_xmit_skb+0x108b/0x1890 net/l2tp/l2tp_core.c:1327
pppol2tp_sendmsg+0x40a/0x5f0 net/l2tp/l2tp_ppp.c:302
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmmsg+0x27c/0x4e0 net/socket.c:2735
__do_sys_sendmmsg net/socket.c:2762 [inline]
__se_sys_sendmmsg net/socket.c:2759 [inline]
__x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd708f9c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd709ef4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fd709215fa0 RCX: 00007fd708f9c799
RDX: 0000000000034000 RSI: 0000200000004380 RDI: 0000000000000004
RBP: 00007fd709032bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd709216038 R14: 00007fd709215fa0 R15: 00007ffef0111698