INFO: task syz.1.3689:19168 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.3689 state:D stack:27088 pid:19168 ppid:15870 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: 0033:0x7fbf28b9e159
RSP: 002b:00007fbf29adf028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbf28e26090 RCX: 00007fbf28b9e159
RDX: 0000000000000002 RSI: 0000200000000900 RDI: 0000000000000004
RBP: 00007fbf28c3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbf28e26128 R14: 00007fbf28e26090 R15: 00007ffecf8d0ac8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2e170 (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: ffffffff8cb2e990 (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/28:
#0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2d7e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6529
2 locks held by kworker/0:2/130:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
#1: ffffc90002e17d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4031:
#0: ffff88802fd0c098 (&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
3 locks held by syz.1.3689/19166:
#0: ffff88807ba285e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff88805f0fc460 (sb_writers#35){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
3 locks held by syz.1.3689/19168:
#0: ffff88802f39c368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
#1: ffff88805f0fc460 (sb_writers#35){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
#2: ffffffff8cdcce48 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783
3 locks held by syz.6.4300/21734:
2 locks held by dhcpcd/21753:
#0: ffff88807b886130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff88807b886130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
#1: ffffffff8cb334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#1: ffffffff8cb334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
1 lock held by dhcpcd/21754:
#0: ffff888089bd4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff888089bd4130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
2 locks held by dhcpcd/21755:
#0: ffff888075688130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff888075688130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
#1: ffffffff8cb334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8cb334b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3c0/0x890 kernel/rcu/tree_exp.h:962
1 lock held by dhcpcd/21756:
#0: ffff888024e26130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff888024e26130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
1 lock held by dhcpcd/21757:
#0: ffff888053b56130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff888053b56130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
1 lock held by dhcpcd/21759:
#0: ffff888061432130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff888061432130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
1 lock held by dhcpcd/21760:
#0: ffff88807a022130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1805 [inline]
#0: ffff88807a022130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3282
2 locks held by dhcpcd-run-hook/21762:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
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: 21759 Comm: dhcpcd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline]
RIP: 0010:lock_acquire+0x135/0x4a0 kernel/locking/lockdep.c:5654
Code: 84 0c 01 00 00 65 8b 05 a9 7e 9e 7e 85 c0 0f 85 45 01 00 00 65 4c 8b 35 19 74 9e 7e 49 81 c6 dc 0a 00 00 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 2f 02 00 00 41 83 3e 00 0f 85 18 01 00
RSP: 0018:ffffc9000cdb7620 EFLAGS: 00000a07
RAX: 1ffff11005fab51b RBX: 0000000000000000 RCX: 0f1af6bcfc5d9300
RDX: 0000000000000000 RSI: ffffffff8adf6880 RDI: ffffffff8adf6840
RBP: ffffc9000cdb7740 R08: ffffffff8e20b46f R09: 1ffffffff1c4168d
R10: dffffc0000000000 R11: fffffbfff1c4168e R12: 0000000000000001
R13: 1ffff920019b6ed0 R14: ffff88802fd5a8dc R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561dd04cc660 CR3: 000000007dd99000 CR4: 00000000003506e0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock_sched include/linux/rcupdate.h:883 [inline]
pfn_valid+0xe9/0x420 include/linux/mmzone.h:1857
page_table_check_clear+0x1e/0x6b0 mm/page_table_check.c:67
ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
zap_pte_range mm/memory.c:1433 [inline]
zap_pmd_range mm/memory.c:1572 [inline]
zap_pud_range mm/memory.c:1601 [inline]
zap_p4d_range mm/memory.c:1622 [inline]
unmap_page_range+0x1905/0x25b0 mm/memory.c:1643
unmap_vmas+0x260/0x390 mm/memory.c:1728
exit_mmap+0x20d/0x970 mm/mmap.c:3250
__mmput+0x118/0x3a0 kernel/fork.c:1210
exit_mm+0x24d/0x350 kernel/exit.c:572
do_exit+0x958/0x2570 kernel/exit.c:874
do_group_exit+0x229/0x2e0 kernel/exit.c:1030
__do_sys_exit_group kernel/exit.c:1041 [inline]
__se_sys_exit_group kernel/exit.c:1039 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1039
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: 0033:0x7f83dc0a36c5
Code: Unable to access opcode bytes at 0x7f83dc0a369b.
RSP: 002b:00007ffc99c96768 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f83dc0a36c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 00007ffc99c96d78 R08: 0000561de85952c0 R09: 0000000000000002
R10: 00000000000000e0 R11: 0000000000000206 R12: 00007ffc99c967b0
R13: 0000561de85968f0 R14: 00007ffc99c969f0 R15: 00007ffc99c967a0