INFO: task syz-executor:20054 blocked for more than 143 seconds.
      Tainted: G     U              6.17.0-rc1-syzkaller-00199-gdfd4b508c8c6 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:23680 pid:20054 tgid:20054 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+0x82a/0x10b0 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: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: 0033:0x7f4ad378ff17
RSP: 002b:00007ffc2ff9cb58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f4ad3811c05 RCX: 00007f4ad378ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc2ff9dca0
RBP: 00007ffc2ff9dc8c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc2ff9dca0
R13: 00007f4ad3811c05 R14: 00000000000ef2b5 R15: 00007ffc2ff9dce0
 </TASK>
INFO: task syz.6.3092:20673 blocked for more than 144 seconds.
      Tainted: G     U              6.17.0-rc1-syzkaller-00199-gdfd4b508c8c6 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.3092      state:D stack:25728 pid:20673 tgid:20668 ppid:18813  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+0x82a/0x10b0 kernel/locking/mutex.c:760
 expkey_flush+0x20/0x90 fs/nfsd/export.c:250
 write_flush.constprop.0+0x2af/0x3d0 net/sunrpc/cache.c:1550
 pde_write fs/proc/inode.c:330 [inline]
 proc_reg_write+0x240/0x330 fs/proc/inode.c:342
 do_loop_readv_writev fs/read_write.c:850 [inline]
 do_loop_readv_writev fs/read_write.c:835 [inline]
 vfs_writev+0x5df/0xde0 fs/read_write.c:1059
 do_writev+0x132/0x340 fs/read_write.c:1103
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f79c498ebe9
RSP: 002b:00007f79c5758038 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f79c4bb5fa0 RCX: 00007f79c498ebe9
RDX: 000000000000000a RSI: 0000200000000200 RDI: 0000000000000008
RBP: 00007f79c4a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f79c4bb6038 R14: 00007f79c4bb5fa0 R15: 00007ffe5109ae88
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G     U              6.17.0-rc1-syzkaller-00199-gdfd4b508c8c6 #0 PREEMPT(full) 
Tainted: [U]=USER
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: 22914 Comm: syz.0.3545 Tainted: G     U              6.17.0-rc1-syzkaller-00199-gdfd4b508c8c6 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 66 cf 54 00 48 89 df 5b e9 9d 55 5a 00 be 03 00 00 00 5b e9 52 75 25 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 34 24 65 48 8b 15 28 b0 1a 12 65 8b 05 39 b0 1a
RSP: 0018:ffffc9000403ea68 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: ffff88801f7c3c00 RSI: ffffffff8b8f2e35 RDI: 0000000000000007
RBP: 0000000000000039 R08: 0000000000000007 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000015479 R12: 0000000000000000
R13: 0000000000000039 R14: dffffc0000000000 R15: ffffc9000403eb58
FS:  00007fb1fb3146c0(0000) GS:ffff8881247c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd9eff6c18 CR3: 000000007d1ba000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 xas_find_conflict+0x893/0xe70 lib/xarray.c:1574
 shmem_add_to_page_cache+0x663/0xa70 mm/shmem.c:925
 shmem_alloc_and_add_folio+0x668/0xc20 mm/shmem.c:1973
 shmem_get_folio_gfp+0x67f/0x1600 mm/shmem.c:2597
 shmem_get_folio mm/shmem.c:2703 [inline]
 shmem_write_begin+0x160/0x300 mm/shmem.c:3353
 generic_perform_write+0x3c2/0x900 mm/filemap.c:4175
 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3528
 __kernel_write_iter+0x317/0xb10 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1296 [inline]
 dump_user_range+0x413/0xb70 fs/coredump.c:1370
 elf_core_dump+0x2929/0x3b60 fs/binfmt_elf.c:2085
 coredump_write fs/coredump.c:1049 [inline]
 vfs_coredump+0x2ba2/0x56d0 fs/coredump.c:1168
 get_signal+0x22e3/0x26d0 kernel/signal.c:3019
 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_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617
RIP: 0033:0x7fb1fa58ebf1
Code: 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 <c3> 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:0000000000000004 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fb1fa7b6180 RCX: 00007fb1fa58ebe9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000100000001
RBP: 00007fb1fa611e19 R08: 0000000000000200 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb1fa7b6218 R14: 00007fb1fa7b6180 R15: 00007ffd87e051c8
 </TASK>