INFO: task syz.0.5341:24489 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.5341 state:D stack:25896 pid:24489 tgid:24483 ppid:17193 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
nfsd_nl_threads_get_doit+0x1b6/0x6f0 fs/nfsd/nfsctl.c:1672
genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x830 net/socket.c:2630
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
__sys_sendmsg net/socket.c:2716 [inline]
__do_sys_sendmsg net/socket.c:2721 [inline]
__se_sys_sendmsg net/socket.c:2719 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8b8af8f6c9
RSP: 002b:00007f8b891d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8b8b1e6090 RCX: 00007f8b8af8f6c9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f8b8b011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b8b1e6128 R14: 00007f8b8b1e6090 R15: 00007ffd2c5d8328
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5588:
#0: ffff88814def70a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5847:
#0: ffff8880250d1358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
2 locks held by syz.1.2560/14996:
#0: ffffffff8f331590 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e226ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690 fs/nfsd/nfsctl.c:1880
2 locks held by syz.0.5341/24489:
#0: ffffffff8f331590 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e226ee8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1b6/0x6f0 fs/nfsd/nfsctl.c:1672
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 24153 Comm: kworker/u8:23 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:format_decode+0x100/0xe30 lib/vsprintf.c:2681
Code: 9e 7d f6 4c 8b 74 24 18 49 81 e6 00 ff ff ff e9 57 05 00 00 4d 89 ee 49 c1 ee 03 48 ba 00 00 00 00 00 fc ff df 41 0f b6 04 16 <84> c0 0f 85 5e 09 00 00 41 c6 45 00 00 48 ff c5 49 89 ef 4d 89 fc
RSP: 0018:ffffc90015d4e470 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: 0000000000000025 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000025 RDI: 0000000000000000
RBP: ffffffff8b6b9346 R08: ffff88807c54bc80 R09: 0000000000000002
R10: 0000000000000025 R11: 0000000000000000 R12: ffffffff8b6b9346
R13: ffffc90015d4e518 R14: 1ffff92002ba9ca3 R15: ffffffff8b6b9346
FS: 0000000000000000(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f73047b5c98 CR3: 000000000dd38000 CR4: 00000000003526f0
Call Trace:
vsnprintf+0x102/0xf00 lib/vsprintf.c:2869
sprintf+0xd9/0x120 lib/vsprintf.c:3089
print_time kernel/printk/printk.c:1354 [inline]
info_print_prefix+0x155/0x310 kernel/printk/printk.c:1380
record_print_text+0x154/0x420 kernel/printk/printk.c:1429
printk_get_next_message+0x26d/0x7b0 kernel/printk/printk.c:2997
console_emit_next_record kernel/printk/printk.c:3065 [inline]
console_flush_all+0x4ca/0xb10 kernel/printk/printk.c:3199
__console_flush_and_unlock kernel/printk/printk.c:3258 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3298
vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423
_printk+0xcf/0x120 kernel/printk/printk.c:2448
ip_vs_schedule+0x1520/0x1c80 net/netfilter/ipvs/ip_vs_core.c:518
udp_conn_schedule+0x332/0x710 net/netfilter/ipvs/ip_vs_proto_udp.c:78
ip_vs_try_to_schedule net/netfilter/ipvs/ip_vs_core.c:1479 [inline]
ip_vs_in_hook+0xbde/0x1b50 net/netfilter/ipvs/ip_vs_core.c:2051
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook+0x217/0x380 include/linux/netfilter.h:273
__ip_local_out+0x4db/0x600 net/ipv4/ip_output.c:120
ip_local_out+0x26/0x70 net/ipv4/ip_output.c:129
iptunnel_xmit+0x5f8/0xa90 net/ipv4/ip_tunnel_core.c:84
udp_tunnel_xmit_skb+0x26e/0x3c0 net/ipv4/udp_tunnel_core.c:193
send4+0xa50/0xed0 drivers/net/wireguard/socket.c:85
wg_socket_send_skb_to_peer+0xd1/0x1d0 drivers/net/wireguard/socket.c:175
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
wg_packet_handshake_send_worker+0x1db/0x320 drivers/net/wireguard/send.c:51
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245