CVE-2025-38066

/// Technical description

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

dm cache: prevent BUG_ON by blocking retries on failed device resumes

A cache device failing to resume due to mapping errors should not be

retried, as the failure leaves a partially initialized policy object.

Repeating the resume operation risks triggering BUG_ON when reloading

cache mappings into the incomplete policy object.

Reproduce steps:

1. create a cache metadata consisting of 512 or more cache blocks,

with some mappings stored in the first array block of the mapping

array. Here we use cache_restore v1.0 to build the metadata.

cat <<EOF >> cmeta.xml

<superblock uuid="" block_size="128" nr_cache_blocks="512" \

policy="smq" hint_width="4">

<mappings>

<mapping cache_block="0" origin_block="0" dirty="false"/>

</mappings>

</superblock>

EOF

dmsetup create cmeta --table "0 8192 linear /dev/sdc 0"

cache_restore -i cmeta.xml -o /dev/mapper/cmeta --metadata-version=2

dmsetup remove cmeta

2. wipe the se

/// 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