cvedb.io
CVE-2025-39759
HIGH · CVSS 7
EPSS exploitation probability: 0%
Published 2025-09-11T17:15:39.827 · Last modified 2026-06-17T09:18:25.453

Summary

In the Linux kernel, the following vulnerability has been resolved: btrfs: qgroup: fix race between quota disable and quota rescan ioctl There's a race between a task disabling quotas and another running the rescan ioctl that can result in a use-after-free of qgroup records from the fs_info->qgroup_tree rbtree. This happens as follows: 1) Task A enters btrfs_ioctl_quota_rescan() -> btrfs_qgroup_rescan(); 2) Task B enters btrfs_quota_disable() and calls btrfs_qgroup_wait_for_completion(), which does nothing because at that point fs_info->qgroup_rescan_running is false (it wasn't set yet by task A); 3) Task B calls btrfs_free_qgroup_config() which starts freeing qgroups from fs_info->qgroup_tree without taking the lock fs_info->qgroup_lock; 4) Task A enters qgroup_rescan_z

Affected products

linux — linux_kernel

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.