Linux Kernel Vulnerability Impacting Id-Mapping Changes by Open Tree Attribute

CVE-2025-39717

What is CVE-2025-39717?

A vulnerability in the Linux kernel allows for unauthorized modifications to id-mappings via open_tree_attr(2) without the required OPEN_TREE_CLONE flag. This inconsistency stems from a flaw where users can bypass safeguards meant to prevent changes to id-mappings, specifically in detached mounts. The issue raises concerns regarding potential use-after-free and locking problems, as previously outlined in related commits. Admins should be vigilant about this security risk and ensure they are using patched versions of the Linux kernel.

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