BSOD 0x81 (SPIN_LOCK_INIT_FAILURE): causes and diagnosis

Status / error code:		Category:

Constant name:
Source:		Operating System:
Description: SPIN_LOCK_INIT_FAILURE means Windows could not initialize spin-lock state required by the affected kernel path.

Could be also:
Constant	Type	OS
ERROR_CHILD_NOT_COMPLETE	Win32 error	Windows
ENETRESET	errno	Solaris
ENOTSUP	errno	Windows

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NMI_HARDWARE_FAILURE	DFS_FILE_SYSTEM

SPIN_LOCK_INIT_FAILURE

Spin-lock initialization failure for SPIN_LOCK_INIT_FAILURE

SPIN_LOCK_INIT_FAILURE is bug check code 0x00000081.

Spin locks are kernel synchronization primitives used at elevated IRQL. This bug check indicates initialization state failed before a later acquire/release path could even use the lock correctly.

How to read it in a dump

Distinguish this from SPIN_LOCK_NOT_OWNED: this is initialization, not ownership release.
Memory corruption, invalid driver global state, or a failed low-level init path can be responsible.
The failing module and allocation context matter.

What to check

Inspect the stack for the driver or subsystem that owns the lock object.
Enable Driver Verifier for suspect boot-start or kernel drivers.
Look for pool corruption before the initialization failure.

References

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