INFO: task syz.0.6041:27068 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.6041 state:D stack:26456 pid:27068 tgid:27066 ppid:15883 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7322
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
nfsd_nl_rpc_status_get_dumpit+0xdc/0x13b0 fs/nfsd/nfsctl.c:1494
genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026
netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331
__netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446
genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075
genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline]
genl_rcv_msg+0x5e1/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 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+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:775 [inline]
__sock_sendmsg net/socket.c:790 [inline]
____sys_sendmsg+0x9b9/0xa20 net/socket.c:2684
___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
__sys_sendmsg net/socket.c:2770 [inline]
__do_sys_sendmsg net/socket.c:2775 [inline]
__se_sys_sendmsg net/socket.c:2773 [inline]
__x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd4d7f9ce59
RSP: 002b:00007fd4d8ef6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd4d8215fa0 RCX: 00007fd4d7f9ce59
RDX: 0000000000000080 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007fd4d8032e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd4d8216038 R14: 00007fd4d8215fa0 R15: 00007fff79523eb8
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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:162 [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+0x388/0x470 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
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 21196 Comm: kworker/u8:40 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 be 47 81 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 3f 9c ec fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 0a 36 66 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900059665a8 EFLAGS: 00000002
RAX: 1ffffffff34f6100 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: ffff888143ad8237 R09: 1ffff1102875b046
R10: dffffc0000000000 R11: ffffffff8544ae10 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a7b0c60 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812527b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056025b2da768 CR3: 000000000e746000 CR4: 00000000003526f0
Call Trace:
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:1973
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3210 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3275 [inline]
serial8250_console_write+0x1373/0x1bd0 drivers/tty/serial/8250/8250_port.c:3360
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x6ea/0xaf0 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
gred_dequeue+0x498/0x670 net/sched/sch_gred.c:273
dequeue_skb net/sched/sch_generic.c:322 [inline]
qdisc_restart net/sched/sch_generic.c:427 [inline]
__qdisc_run+0x24c/0x1620 net/sched/sch_generic.c:445
qdisc_run include/net/pkt_sched.h:120 [inline]
__dev_xmit_skb net/core/dev.c:4294 [inline]
__dev_queue_xmit+0x1c00/0x37f0 net/core/dev.c:4833
dev_queue_xmit include/linux/netdevice.h:3436 [inline]
neigh_hh_output include/net/neighbour.h:544 [inline]
neigh_output include/net/neighbour.h:558 [inline]
ip_finish_output2+0xbda/0x10b0 net/ipv4/ip_output.c:236
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip_output+0x29f/0x450 net/ipv4/ip_output.c:437
iptunnel_xmit+0x626/0xd10 net/ipv4/ip_tunnel_core.c:97
udp_tunnel_xmit_skb+0x27f/0x3c0 net/ipv4/udp_tunnel_core.c:187
geneve_xmit_skb drivers/net/geneve.c:1419 [inline]
geneve_xmit+0x2337/0x32d0 drivers/net/geneve.c:1549
__netdev_start_xmit include/linux/netdevice.h:5387 [inline]
netdev_start_xmit include/linux/netdevice.h:5396 [inline]
xmit_one net/core/dev.c:3889 [inline]
dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3905
__dev_queue_xmit+0x1435/0x37f0 net/core/dev.c:4872
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x337/0x540 net/ipv6/ip6_output.c:246
dst_output include/net/dst.h:471 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
ndisc_send_skb+0xcb2/0x1650 net/ipv6/ndisc.c:512
ndisc_send_ns+0xd7/0x160 net/ipv6/ndisc.c:671
addrconf_dad_work+0xa8d/0x15c0 net/ipv6/addrconf.c:4317
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
kthread+0x388/0x470 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