CVE-2025-38049: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: x86/resctrl: Fix allocation of cleanest CLOSID on platforms with no monitors Commit 6eac36bb9eb0 ("x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty_rmid") added logic that causes resctrl to search for the CLOSID with the fewest dirty cache lines when creating a new control group, if requested by the arch code. This depends on the values read from the llc_occupancy counters. The logic is applicable to architectures where the CLOSID effectively forms part of the monitoring identifier and so do not allow complete freedom to choose an unused monitoring identifier for a given CLOSID. This support missed that some platforms may not have these counters. This causes a NULL pointer dereference when creating a new control group as the array was not allocated by dom_data_init(). As this feature isn't necessary on platforms that don't have cache occupancy monitors, add this to the check that occurs when a new control group is allocated.

Business impact

Successful exploitation of CVE-2025-38049, a medium vulnerability (CVSS 5.5) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
• Reference
• Reference
• Reference