CVE-2025-39759 Affecting dlm-kmp-default package, versions <6.4.0-150600.23.73.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.04% (10th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-SLES156-DLMKMPDEFAULT-13582090
  • published16 Oct 2025
  • disclosed15 Oct 2025

Introduced: 15 Oct 2025

NewCVE-2025-39759  (opens in a new tab)

How to fix?

Upgrade SLES:15.6 dlm-kmp-default to version 6.4.0-150600.23.73.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dlm-kmp-default package and not the dlm-kmp-default package as distributed by SLES. See How to fix? for SLES:15.6 relevant fixed versions and status.

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_zero_tracking() which starts iterating the fs_info->qgroup_tree tree while holding fs_info->qgroup_lock, but task B is freeing qgroup records from that tree without holding the lock, resulting in a use-after-free.

Fix this by taking fs_info->qgroup_lock at btrfs_free_qgroup_config(). Also at btrfs_qgroup_rescan() don't start the rescan worker if quotas were already disabled.

CVSS Base Scores

version 3.1