Linux Kernel Vulnerability in Ceph Local Caching Feature

CVE-2025-38534

What is CVE-2025-38534?

A vulnerability in the Linux kernel's netfs implementation affects the Ceph file system's local caching functionality. The issue arises during the copy-to-cache operation, where a newly initiated write request asynchronously attempts to notify the application upon completion. However, due to a misconfiguration where the NETFS_RREQ_OFFLOAD_COLLECTION flag is not set, the application is not in a waiting state to receive the notification. This results in the request hanging indefinitely. The fix involves setting the NETFS_RREQ_OFFLOAD_COLLECTION flag, allowing the notification to be queued properly, thereby preventing disruption in application operations.

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