INFO: task syz-executor:27209 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23592 pid:27209 tgid:27209 ppid:1      task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
 nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:596
 nfsd_umount+0x48/0xe0 fs/nfsd/nfsctl.c:1386
 deactivate_locked_super+0xc1/0x1a0 fs/super.c:474
 deactivate_super fs/super.c:507 [inline]
 deactivate_super+0xde/0x100 fs/super.c:503
 cleanup_mnt+0x225/0x450 fs/namespace.c:1375
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:43
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f38ce18ff17
RSP: 002b:00007ffe44d4d6b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f38ce18ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe44d4d770
RBP: 00007ffe44d4d770 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe44d4e800
R13: 00007f38ce211c05 R14: 000000000012969d R15: 00007ffe44d4e840
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf0e/0x1260 kernel/hung_task.c:491
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 27949 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x70 kernel/kcov.c:217
Code: a9 00 01 ff 00 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 3c 16 00 00 85 c0 74 2b 8b 82 18 16 00 00 <83> f8 02 75 20 48 8b 8a 20 16 00 00 8b 92 1c 16 00 00 48 8b 01 48
RSP: 0018:ffffc9000445f570 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8205adde
RDX: ffff888034af0000 RSI: ffffffff8205adeb RDI: 0000000000000005
RBP: 00000000000a088f R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000007b9c R12: 1ffff9200088beaf
R13: ffff8880627fdc80 R14: 00007f2ff675b000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8881246c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000082a000 CR3: 000000006478a000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 vm_normal_page+0xcb/0x2c0 mm/memory.c:640
 zap_present_ptes mm/memory.c:1551 [inline]
 do_zap_pte_range mm/memory.c:1682 [inline]
 zap_pte_range mm/memory.c:1726 [inline]
 zap_pmd_range mm/memory.c:1818 [inline]
 zap_pud_range mm/memory.c:1847 [inline]
 zap_p4d_range mm/memory.c:1868 [inline]
 unmap_page_range+0xcca/0x42c0 mm/memory.c:1889
 unmap_single_vma.constprop.0+0x153/0x240 mm/memory.c:1932
 unmap_vmas+0x218/0x470 mm/memory.c:1976
 exit_mmap+0x1b9/0xb90 mm/mmap.c:1280
 __mmput+0x12a/0x410 kernel/fork.c:1130
 mmput+0x62/0x70 kernel/fork.c:1152
 exit_mm kernel/exit.c:582 [inline]
 do_exit+0x7c7/0x2bf0 kernel/exit.c:949
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102
 get_signal+0x2673/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x790 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x84/0x110 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x3f6/0x490 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ff6bc14a5
Code: Unable to access opcode bytes at 0x7f2ff6bc147b.
RSP: 002b:00007ffd3bd6dc70 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 000000000000017e RCX: 00007f2ff6bc14a5
RDX: 00007ffd3bd6dcb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd3bd6dd1c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388
R13: 00000000000927c0 R14: 000000000014fdc0 R15: 00007ffd3bd6dd70
 </TASK>