INFO: task syz.5.526:6541 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.526 state:D stack:27328 pid:6541 ppid:4907 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5257 [inline]
__schedule+0x1089/0x4140 kernel/sched/core.c:6584
schedule+0xb9/0x180 kernel/sched/core.c:6660
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6719
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x562/0xb40 kernel/locking/mutex.c:747
write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
vfs_write+0x2dc/0x9a0 fs/read_write.c:582
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcf22d9f559
RSP: 002b:00007fcf23d58028 EFLAGS: 00000246
ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fcf23025fa0 RCX: 00007fcf22d9f559
RDX: 0000000000000005 RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00007fcf22e36b50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcf23026038 R14: 00007fcf23025fa0 R15: 00007ffe4cf89898
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0:
ffffffff8db2e3f0
(
rcu_tasks.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x33/0xce0 kernel/rcu/tasks.h:543
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8db2ec30 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xce0 kernel/rcu/tasks.h:543
3 locks held by kworker/1:0/22:
#0:
ffff88814c384938
(
(wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#2: ffffffff8ed6b9e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4687
1 lock held by khungtaskd/27:
#0:
ffffffff8db2daa0
(
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
3 locks held by kworker/u4:5/303:
1 lock held by dhcpcd/3939:
#0: ffffffff8ed6b9e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8ed6b9e8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x80d/0xfb0 net/core/rtnetlink.c:6163
2 locks held by getty/4032:
#0:
ffff88814c725098
(&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}
, at: n_tty_read+0x430/0x1400 drivers/tty/n_tty.c:2198
3 locks held by syz.4.315/5652:
#0: ffff88802446eae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff8880786ca460 (sb_writers#17){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2:
ffffffff8ddcd208
(
nfsd_mutex
){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
2 locks held by kworker/1:10/5945:
#0: ffff888018472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900035a7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
4 locks held by kworker/0:14/6471:
3 locks held by syz.5.526/6541:
#0: ffff88807830b4e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff88805dc56460 (sb_writers#17){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffffffff8ddcd208 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
4 locks held by udevd/7308:
#0: ffff88802a6a1b08
(
&p->lock
){+.+.}-{3:3}, at: raw_spin_rq_lock_nested+0x25/0x130 kernel/sched/core.c:549
#1: ffff8880b8c27888 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x400/0x740 kernel/sched/psi.c:999
#2: ffff88807bd6c958 (&ep->lock){....}-{2:2}, at: ep_poll_callback+0x78/0xa00 fs/eventpoll.c:1150
#3:
ffff88807bd6c8a8
(&ep->wq){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:137 [inline]
(&ep->wq){....}-{2:2}, at: __wake_up_sync_key kernel/sched/wait.c:208 [inline]
(&ep->wq){....}-{2:2}, at: __wake_up_sync+0xf8/0x190 kernel/sched/wait.c:240
1 lock held by syz.2.1132/9155:
#0: ffffffff8ed6b9e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8ed6b9e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3506
1 lock held by syz.9.1130/9158:
#0: ffffffff8db337b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8db337b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
4 locks held by syz.9.1130/9161:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf0e/0xf50 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9161 Comm: syz.9.1130 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461
Code: e8 d2 03 00 fd 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 83 67 51 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c
RSP: 0018:ffffc9000684e2f8 EFLAGS: 00000006
RAX: 1ffffffff2ffdf05 RBX: 00000000000003f9 RCX: 0000000000000000
RDX: 00000000000003f9 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000684e4d0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000d09c40 R12: dffffc0000000000
R13: ffffffff97cabe00 R14: ffffffff97feff40 R15: 0000000000000000
FS: 00007effab1476c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555783254e8 CR3: 0000000040c21000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_port_in include/linux/serial_core.h:668 [inline]
serial8250_console_write+0x280/0x18b0 drivers/tty/serial/8250/8250_port.c:3450
call_console_driver kernel/printk/printk.c:1977 [inline]
console_emit_next_record+0x795/0xb50 kernel/printk/printk.c:2777
console_flush_all kernel/printk/printk.c:-1 [inline]
console_unlock+0x223/0x630 kernel/printk/printk.c:2906
vprintk_emit+0x4b3/0x6a0 kernel/printk/printk.c:2303
_printk+0xda/0x130 kernel/printk/printk.c:2328
__dynamic_netdev_dbg+0x372/0x540 lib/dynamic_debug.c:937
bond_netdev_event+0xdc8/0xe50 drivers/net/bonding/bond_main.c:4079
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455
netdev_state_change+0xe0/0x170 net/core/dev.c:1403
do_setlink+0x508/0x29c0 net/core/rtnetlink.c:3079
rtnl_group_changelink net/core/rtnetlink.c:3375 [inline]
__rtnl_newlink net/core/rtnetlink.c:3632 [inline]
rtnl_newlink+0x10bc/0x1f90 net/core/rtnetlink.c:3669
rtnetlink_rcv_msg+0x863/0xfb0 net/core/rtnetlink.c:6166
netlink_rcv_skb+0x1ef/0x440 net/netlink/af_netlink.c:2516
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x7ad/0x920 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8ad/0xbd0 net/netlink/af_netlink.c:1877
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519
___sys_sendmsg+0x2a2/0x360 net/socket.c:2573
__sys_sendmsg net/socket.c:2602 [inline]
__do_sys_sendmsg net/socket.c:2611 [inline]
__se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7effaa19f559
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:00007effab147028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007effaa425fa0 RCX: 00007effaa19f559
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007effaa236b50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007effaa426038 R14: 00007effaa425fa0 R15: 00007ffd11677528
kcov: kcov_remote_start: handle = 100000000000005, context: softirq
kcov: kcov_start: t = ffff888018743c00, size = 262144, area = ffffc90002332000
kcov: kcov_move_area: ffffc90023c0f000 1048576 <= ffffc90002332000 81
kcov: kcov_remote_start: handle = 100000000000005, context: softirq
kcov: kcov_start: t = ffff88802ba98000, size = 262144, area = ffffc90002332000
kcov: kcov_move_area: ffffc90023c0f000 1048576 <= ffffc90002332000 2
kcov: kcov_remote_start: handle = 100000000000005, context: softirq
kcov: kcov_start: t = ffff88802ba98000, size = 262144, area = ffffc90002332000
kcov: kcov_move_area: ffffc90023c0f000 1048576 <= ffffc90002332000 8