Linux Kernel Vulnerability in dm Cache Policy for Device Mapping Failures

CVE-2025-38066

What is CVE-2025-38066?

A vulnerability exists in the Linux kernel affecting the dm cache mechanism, where a cache device may fail to resume due to mapping errors. When attempting to load cache mappings after a failed resume operation, the system risks triggering a critical error, denoted by the BUG_ON assertion. This situation arises when the cache metadata encompasses partially initialized policy objects, leaving the system vulnerable to operational disruptions. The issue has been addressed by preventing retries on resume operations when initial attempts fail, thereby mitigating the risks associated with incomplete cache policies.

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