INFO: task syz.4.384:5838 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.384 state:D stack:27056 pid:5838 ppid:4291 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5246 [inline]
__schedule+0x107f/0x4030 kernel/sched/core.c:6563
schedule+0xb9/0x180 kernel/sched/core.c:6639
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6698
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x548/0xae0 kernel/locking/mutex.c:747
nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783
write_threads+0x2ea/0x350 fs/nfsd/nfsctl.c:424
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: 0033:0x7f68c5f9e199
RSP: 002b:00007f68c6f10028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f68c6226090 RCX: 00007f68c5f9e199
RDX: 0000000000000002 RSI: 0000200000000340 RDI: 0000000000000003
RBP: 00007f68c60358e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f68c6226128 R14: 00007f68c6226090 R15: 00007ffcbb1d9378
Showing all locks held in the system:
2 locks held by kworker/u4:0/9:
1 lock held by rcu_tasks_kthre/12:
#0:
ffffffff8cb2e230 (rcu_tasks.tasks_gp_mutex
){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2ea50 (rcu_tasks_trace.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0:
ffffffff8cb2d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
ffffffff8cb2d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
ffffffff8cb2d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
2 locks held by getty/4031:
#0:
ffff88814d8ea098 (&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+0x41e/0x1360 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:7/4329:
#0:
ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc900040b7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
6 locks held by kworker/u4:6/4336:
3 locks held by syz.4.384/5837:
#0: ffff8880771cb9e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888079fee460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffffffff8cdccf08 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
3 locks held by syz.4.384/5838:
#0: ffff888028554ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff888079fee460 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffffffff8cdccf08 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783
1 lock held by syz.7.993/8343:
2 locks held by dhcpcd/8350:
#0: ffff88802deee130
(
sk_lock-AF_PACKET){+.+.}-{0:0}, at: inode_lock include/linux/fs.h:764 [inline]
sk_lock-AF_PACKET){+.+.}-{0:0}, at: __sock_release net/socket.c:653 [inline]
sk_lock-AF_PACKET){+.+.}-{0:0}, at: sock_close+0x82/0x210 net/socket.c:1400
#1: ffff8880b8e3acd8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x98/0x130 kernel/sched/core.c:546
2 locks held by dhcpcd/8352:
#0: ffff88807c836130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff88807c836130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3285
#1: ffffffff8cb33578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8cb33578 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
1 lock held by dhcpcd/8353:
#0: ffff88807e330130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff88807e330130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3285
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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 1 to CPUs 0:
nf_nat: Already setup manip DST for ct ffff888073440600 (status bits 0x188)
NMI backtrace for cpu 0
CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:211
Code: 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 20 95 9e 0c 48 89 de 5b e9 57 90 50 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d b4 28 80 7e 65 8b 15 b5 28 80 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000007e58 EFLAGS: 00000086
RAX: ffffffff81722077 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: 0000000000010100 RSI: 0000000000000004 RDI: 0000000000000009
RBP: ffff8880b8e2a840 R08: ffff8880b8e2af1f R09: ffff8880b8e2af10
R10: dffffc0000000000 R11: ffffed10171c55e4 R12: 7fffffffffffffff
R13: 0000000000000010 R14: 0000000000000000 R15: ffff8880783471a0
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b535cd24b0 CR3: 0000000073927000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__hrtimer_next_event_base+0xd7/0x2d0 kernel/time/hrtimer.c:537
__hrtimer_get_next_event kernel/time/hrtimer.c:599 [inline]
hrtimer_update_next_event kernel/time/hrtimer.c:625 [inline]
hrtimer_interrupt+0x426/0x980 kernel/time/hrtimer.c:1880
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1948 [inline]
RIP: 0010:vprintk_emit+0x48b/0x6a0 kernel/printk/printk.c:2302
Code: 86 01 00 00 e8 56 0f 1b 00 41 89 df 4d 85 f6 48 8b 5c 24 08 75 07 e8 44 0f 1b 00 eb 06 e8 3d 0f 1b 00 fb 48 c7 c7 60 1b b2 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 bd c7
RSP: 0018:ffffc90000147300 EFLAGS: 00000246
RAX: ffffffff81673743 RBX: ffffffff816735d5 RCX: ffff88813fef3c00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffffffff8cb21b60
RBP: ffffc900001473f0 R08: ffffffff8e20d96f R09: 1ffffffff1c41b2d
R10: dffffc0000000000 R11: fffffbfff1c41b2e R12: dffffc0000000000
R13: 1ffff92000028e64 R14: 0000000000000200 R15: 000000000000004b
_printk+0xda/0x130 kernel/printk/printk.c:2328
__dynamic_pr_debug+0x196/0x240 lib/dynamic_debug.c:875
nf_nat_inet_fn+0xb19/0xb30 net/netfilter/nf_nat_core.c:763
nf_nat_ipv4_fn net/netfilter/nf_nat_proto.c:645 [inline]
nf_nat_ipv4_pre_routing+0x196/0x390 net/netfilter/nf_nat_proto.c:655
nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline]
nf_hook_slow+0xb9/0x200 net/netfilter/core.c:614
nf_hook include/linux/netfilter.h:257 [inline]
NF_HOOK+0x219/0x3b0 include/linux/netfilter.h:300
__netif_receive_skb_one_core net/core/dev.c:5619 [inline]
__netif_receive_skb+0xcc/0x290 net/core/dev.c:5733
process_backlog+0x37c/0x710 net/core/dev.c:6061
__napi_poll+0xbb/0x460 net/core/dev.c:6628
napi_poll net/core/dev.c:6695 [inline]
net_rx_action+0x622/0xbc0 net/core/dev.c:6809
handle_softirqs+0x291/0x910 kernel/softirq.c:596
run_ksoftirqd+0xa4/0x100 kernel/softirq.c:968
smpboot_thread_fn+0x667/0xa30 kernel/smpboot.c:164
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
nf_conntrack: new packet for ffff888073441380
nf_nat: Already setup manip DST for ct ffff888073441380 (status bits 0x188)
virtqueue callback for ffff888145a67a00 (ffffffff847670d0)
nf_nat: Already setup manip SRC for ct ffff888073441380 (status bits 0x188)
virtqueue interrupt with no work for ffff888145a67800
wireguard: wg0: Handshake for peer 39 ([::1]:20003/0%0) did not complete after 5 seconds, retrying (try 12)
virtqueue interrupt with no work for ffff888145a67600
wireguard: wg1: Handshake for peer 10 (127.0.0.1:20003) did not complete after 5 seconds, retrying (try 17)
wireguard: wg0: Handshake for peer 19 ([::1]:20002/0%0) did not complete after 5 seconds, retrying (try 2)
sctp: sctp_addr_wq_timeout_handler: the first ent in wq:ffff888073222a98 is addr:fc00:: for cmd:0 at entry:ffff888058ab9d00
sctp: sctp_addr_wq_timeout_handler: this is on DAD, trying 500 sec later
nf_conntrack: new packet for ffff888029193080
nf_nat: Already setup manip DST for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip SRC for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip SRC for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip DST for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip SRC for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip DST for ct ffff888073440600 (status bits 0x188)
nf_nat: Already setup manip SRC for ct ffff888073440600 (status bits 0x188)
nf_nat: Already setup manip DST for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip SRC for ct ffff888029193080 (status bits 0x188)
nf_nat: Already setup manip DST for ct ffff888073440600 (status bits 0x188)
nf_nat: Already setup manip SRC for ct ffff888073440600 (status bits 0x188)
nf_conntrack: new packet for ffff888073440600