INFO: task syz.1.214:5190 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.214       state:D stack:27920 pid:5190  ppid:4275   flags:0x00004004
Call Trace:
 <TASK>
 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
 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: 0033:0x7faa8019e019
RSP: 002b:00007faa810e8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007faa80426270 RCX: 00007faa8019e019
RDX: 0000000000000002 RSI: 0000200000000540 RDI: 0000000000000006
RBP: 00007faa8023500c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faa80426308 R14: 00007faa80426270 R15: 00007ffd91d78fb8
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2e4f0 (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: ffffffff8cb2ed10 (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: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2db60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6527
2 locks held by getty/4029:
 #0: ffff88802fcb1098 (&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
1 lock held by syz-executor/4274:
 #0: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
 #0: ffffffff8cb33838 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962
2 locks held by kworker/1:4/4284:
 #0: 
ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc900042d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
1 lock held by udevd/4471:
 #0: ffff888148cfdf28 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
 #0: ffff888148cfdf28 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: blkdev_read_iter+0x41f/0x570 block/fops.c:667
2 locks held by kworker/u4:14/4728:
 #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
 #1: ffffc900055a7d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work+0x7b4/0x1160 kernel/workqueue.c:2267
3 locks held by syz.1.214/5183:
 #0: ffff888027ff9c68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff8880786f6460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_svc+0x61/0xab0 fs/nfsd/nfssvc.c:783
3 locks held by syz.1.214/5190:
 #0: ffff88807e1559e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff8880786f6460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
3 locks held by syz.2.659/6821:
 #0: ffff8880265e9268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff888028e1c460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846
3 locks held by syz.5.737/7063:
 #0: ffff88807c2de368 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff888052998460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:681
3 locks held by syz.5.737/7064:
 #0: ffff8880266dafe8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038
 #1: ffff888052998460 (sb_writers#15){.+.+}-{0:0}, at: vfs_write+0x270/0x9a0 fs/read_write.c:580
 #2: ffffffff8cdcce08 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:846

=============================================

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:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5088 Comm: kworker/u4:18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:444 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:1030 [inline]
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0xbb/0x4a0 kernel/locking/lockdep.c:5647
Code: 35 7a 20 9e 7e 48 c7 c0 f0 0c 21 8e 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 9d 02 00 00 44 3b 35 ab 13 bd 0c 0f 83 a2 01 00 00 <45> 89 f4 41 c1 ee 06 4a 8d 3c f5 e8 0a 21 8e be 08 00 00 00 e8 0c
RSP: 0018:ffffc9000d7e7ac0 EFLAGS: 00000297
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8cb2db60
RBP: ffffc9000d7e7bc8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1c4215e R12: dffffc0000000000
R13: 1ffff92001afcf64 R14: 0000000000000001 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556f0a2a78 CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>