CVE-2025-71269

A resource accounting flaw was found in the Linux kernel's btrfs filesystem. When creating an inline extent fails with -ENOSPC, the code falls back to the normal COW (copy-on-write) path. However, it incorrectly frees the reserved qgroup data even though the data will still be written via the fallback path. This causes qgroup accounting to become inconsistent, potentially allowing data writes to exceed quota limits.

This flaw affects btrfs filesystems using qgroups for quota management. The incorrect qgroup reservation handling occurs in an error recovery path when inline extent creation fails due to space pressure. While this can cause quota accounting inconsistencies, it requires specific conditions (qgroups enabled, ENOSPC during inline extent creation) and does not directly lead to code execution or data corruption.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.