CVE-2025-22076 in Linux
Summary
by MITRE • 04/16/2025
In the Linux kernel, the following vulnerability has been resolved:
exfat: fix missing shutdown check
xfstests generic/730 test failed because after deleting the device that still had dirty data, the file could still be read without returning an error. The reason is the missing shutdown check in ->read_iter.
I also noticed that shutdown checks were missing from ->write_iter, ->splice_read, and ->mmap. This commit adds shutdown checks to all of them.
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Analysis
by VulDB Data Team • 02/15/2026
The vulnerability identified as CVE-2025-22076 represents a critical flaw in the Linux kernel's exFAT filesystem implementation that stems from inadequate shutdown validation mechanisms within several core filesystem operations. This issue manifests when filesystem devices are abruptly removed or shut down while containing unsynchronized data, creating a dangerous condition where the system continues to permit data access operations despite the underlying storage being in an inconsistent state. The problem was initially detected through the failure of xfstests generic/730, which specifically tests the behavior of filesystems when devices are deleted while containing dirty data, highlighting the fundamental security and data integrity risks associated with this oversight.
The technical root cause of this vulnerability lies in the absence of proper shutdown validation checks within multiple filesystem operation handlers within the exFAT driver implementation. Specifically, the missing shutdown checks affect four critical operations: ->read_iter, ->write_iter, ->splice_read, and ->mmap. These operations are essential components of the filesystem's interface that handle various data access patterns and memory management functions. When shutdown checks are omitted from these handlers, the kernel fails to validate whether the filesystem is in a valid state before proceeding with data operations, potentially allowing access to corrupted or inconsistent data structures. This flaw directly violates the expected behavior of filesystem drivers, which should always verify the integrity and availability of underlying storage before permitting any data access operations.
The operational impact of this vulnerability extends beyond simple data corruption concerns to encompass serious security implications and system stability risks. When a device containing dirty data is deleted without proper shutdown validation, the system continues to allow read operations to succeed even though the underlying storage is no longer accessible or reliable. This creates a potential attack vector where malicious actors could exploit the inconsistent state to access sensitive data or manipulate filesystem structures, potentially leading to data leakage, system crashes, or privilege escalation scenarios. The vulnerability affects systems running Linux kernels with exFAT filesystem support and could be particularly dangerous in enterprise environments where storage devices are frequently managed or hot-swapped, as it undermines the fundamental data integrity guarantees that filesystem drivers are expected to provide.
The resolution for CVE-2025-22076 involves implementing comprehensive shutdown checks across all affected filesystem operations, ensuring that each handler validates the filesystem's operational state before proceeding with data access. This fix aligns with established security practices and follows the principle of defensive programming, where all system interfaces validate preconditions before executing operations. The mitigation strategy requires kernel updates that incorporate proper shutdown validation logic, ensuring that operations fail appropriately when the filesystem is not in a valid state for data access. This approach directly addresses the weakness identified in the Common Weakness Enumeration catalog under CWE-665, which covers improper initialization of resources, and aligns with ATT&CK techniques related to privilege escalation and data manipulation by ensuring proper state validation before resource access. Organizations should prioritize applying these kernel updates to protect against potential exploitation of this vulnerability, particularly in environments where exFAT filesystems are actively used and where device management operations occur frequently.