INFO: task syz-executor:6806 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21800 pid:6806  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 nfsd_shutdown_threads+0x53/0x1a0 fs/nfsd/nfssvc.c:638
 nfsd_umount+0x42/0xc0 fs/nfsd/nfsctl.c:1464
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x3d7/0x460 fs/namespace.c:1259
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcfd399f317
RSP: 002b:00007ffc15ce80f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fcfd3a34474 RCX: 00007fcfd399f317
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc15ce81b0
RBP: 00007ffc15ce81b0 R08: 00007ffc15ce91b0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc15ce9240
R13: 00007fcfd3a34474 R14: 00000000000c0146 R15: 00007ffc15ce9280
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by udevd/5141:
1 lock held by dhcpcd/5436:
2 locks held by getty/5535:
 #0: ffff88814cb690a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032832f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by syz-executor/6806:
 #0: ffff888063d2c0e0 (&type->s_umount_key#89){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888063d2c0e0 (&type->s_umount_key#89){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888063d2c0e0 (&type->s_umount_key#89){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
 #1: ffffffff8d3e1688 (nfsd_mutex){+.+.}-{3:3}, at: nfsd_shutdown_threads+0x53/0x1a0 fs/nfsd/nfssvc.c:638
2 locks held by kworker/1:12/10108:
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000cabfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000cabfd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
3 locks held by syz.0.1285/12808:
 #0: ffff88804cc45248 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff888026da6418 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
 #2: ffffffff8d3e1688 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843
3 locks held by syz.7.1378/13374:
 #0: ffff8880271cb9c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff88802e1b2418 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
 #2: ffffffff8d3e1688 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb7/0xfa0 fs/nfsd/nfsctl.c:843

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 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+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9307 Comm: kworker/u4:35 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:memset_orig+0x75/0xac arch/x86/lib/memset_64.S:90
Code: 89 47 30 48 89 47 38 48 8d 7f 40 75 d8 0f 1f 84 00 00 00 00 00 89 d1 83 e1 38 74 14 c1 e9 03 66 0f 1f 44 00 00 ff c9 48 89 07 <48> 8d 7f 08 75 f5 83 e2 07 74 0a ff ca 88 07 48 8d 7f 01 75 f6 4c
RSP: 0018:ffffc900049ff7b8 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff8880b8e39090 RCX: 0000000000000001
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900049ffa10
RBP: ffffc900049ff8b0 R08: ffffc900049ffa1f R09: 0000000000000000
R10: ffffc900049ffa10 R11: fffff5200093ff44 R12: ffffc900049ff9e0
R13: ffffc900049ff800 R14: dffffc0000000000 R15: 1ffff9200093fefc
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f66b33ef2f8 CR3: 000000002ba03000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 crng_fast_key_erasure+0x14f/0x260 drivers/char/random.c:297
 crng_make_state+0x259/0x700 drivers/char/random.c:364
 _get_random_bytes+0x100/0x250 drivers/char/random.c:378
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:776 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x60c/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>