CVE-2024-41084

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

cxl/region: Avoid null pointer dereference in region lookup

cxl_dpa_to_region() looks up a region based on a memdev and DPA.

It wrongly assumes an endpoint found mapping the DPA is also of

a fully assembled region. When not true it leads to a null pointer

dereference looking up the region name.

This appears during testing of region lookup after a failure to

assemble a BIOS defined region or if the lookup raced with the

assembly of the BIOS defined region.

Failure to clean up BIOS defined regions that fail assembly is an

issue in itself and a fix to that problem will alleviate some of

the impact. It will not alleviate the race condition so let's harden

this path.

The behavior change is that the kernel oops due to a null pointer

dereference is replaced with a dev_dbg() message noting that an

endpoint was mapped.

Additional comments are added so that future users of this function

can more clearly understand what it

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References