INFO: task syz-executor:12560 blocked for more than 143 seconds.
      Not tainted 6.17.0-rc1-syzkaller-00224-g8d561baae505 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23560 pid:12560 tgid:12560 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+0xbe/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:1378
 task_work_run+0x150/0x240 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: 0033:0x7f3b8038ff17
RSP: 002b:00007ffd6187ef58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3b80411c05 RCX: 00007f3b8038ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd618800a0
RBP: 00007ffd6188008c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd618800a0
R13: 00007f3b80411c05 R14: 000000000010d59e R15: 00007ffd618800e0
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.17.0-rc1-syzkaller-00224-g8d561baae505 #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+0x3c2/0x780 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 25410 Comm: syz.7.3667 Not tainted 6.17.0-rc1-syzkaller-00224-g8d561baae505 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__orc_find+0x3d/0xf0 arch/x86/kernel/unwind_orc.c:104
Code: 53 48 83 ec 08 85 d2 0f 84 99 00 00 00 49 89 fe 48 89 f0 49 39 fc 72 7b 48 b9 00 00 00 00 00 fc ff df 49 89 ff 48 89 fd eb 0c <48> 8d 6b 04 49 89 df 49 39 ec 72 4e 4c 89 e2 48 29 ea 48 89 d6 48
RSP: 0018:ffffc90028427698 EFLAGS: 00000216
RAX: ffffffff913ab42e RBX: ffffffff90b87850 RCX: dffffc0000000000
RDX: ffffffff81001269 RSI: 0000000000000000 RDI: ffffffff90b8781c
RBP: ffffffff90b8781c R08: ffffffff913ab4d6 R09: 0000000000000000
R10: ffffc90028427748 R11: 0000000000000012 R12: ffffffff90b87888
R13: ffffffff810012a5 R14: ffffffff90b8781c R15: ffffffff90b8781c
FS:  0000000000000000(0000) GS:ffff8881247c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dea3300000 CR3: 0000000055f2c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
 unwind_next_frame+0x2ec/0x20a0 arch/x86/kernel/unwind_orc.c:494
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 vfree+0x1fd/0xb50 mm/vmalloc.c:3434
 kcov_put kernel/kcov.c:439 [inline]
 kcov_put kernel/kcov.c:435 [inline]
 kcov_close+0x34/0x60 kernel/kcov.c:535
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x86f/0x2bf0 kernel/exit.c:961
 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 kernel/entry/common.c:40 [inline]
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:73
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x401000
Code: Unable to access opcode bytes at 0x400fd6.
RSP: 002b:000000000000000d EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00007fa7f93b6270 RCX: 00007fa7f918ebe9
RDX: 00002000000001c0 RSI: 0000000000000005 RDI: 0000000000000007
RBP: 00007fa7f9211e19 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa7f93b6308 R14: 00007fa7f93b6270 R15: 00007ffca3c1c4f8
 </TASK>