CVE-2023-52489

/// Technical description

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

mm/sparsemem: fix race in accessing memory_section->usage

The below race is observed on a PFN which falls into the device memory

region with the system memory configuration where PFN's are such that

[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL]. Since normal zone start and end

pfn contains the device memory PFN's as well, the compaction triggered

will try on the device memory PFN's too though they end up in NOP(because

pfn_to_online_page() returns NULL for ZONE_DEVICE memory sections). When

from other core, the section mappings are being removed for the

ZONE_DEVICE region, that the PFN in question belongs to, on which

compaction is currently being operated is resulting into the kernel crash

with CONFIG_SPASEMEM_VMEMAP enabled. The crash logs can be seen at [1].

compact_zone() memunmap_pages

------------- ---------------

__pageblock_pfn_to_page

......

(a)pfn_valid():

valid_section()//return true

(b)_

/// 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