CVE Catalog

CVE-2026-53061

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

7th percentile - higher than 7% of all known CVEs

Summary

In the Linux kernel, the dm-cache module has a vulnerability in dirty mapping checking when switching to passthrough mode. The bug arises from an assumption that table reload occurs after suspension, which is broken by LVM's preload mechanism. This can lead to loading dirty mappings into passthrough mode, causing data loss.

Risk Assessment

The organization risks data loss when using writeback cache with zero migration threshold and switching to passthrough mode. A local attacker could exploit this to corrupt or lose data.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit moving the check to the preresume phase). Before updating, avoid switching to passthrough mode in writeback caches with zero migration threshold.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: dm cache: fix dirty mapping checking in passthrough mode switching As mentioned in commit 9b1cc9f251af ("dm cache: share cache-metadata object across inactive and active DM tables"), dm-cache assumed table reload occurs after suspension, while LVM's table preload breaks this assumption. The dirty mapping check for passthrough mode was designed around this assumption and is performed during table creation, causing the check to fail with preload while metadata updates are ongoing. This risks loading dirty mappings into passthrough mode, resulting in data loss. Reproduce steps: 1. Create a writeback cache with zero migration_threshold to produce dirty mappings dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 262144 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 262144 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writeback smq \ 2 migration_threshold 0" 2. Preload a table in passthrough mode dmsetup reload cache --table "0 262144 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 passthrough smq 0" 3. Write to the first cache block to make it dirty fio --filename=/dev/mapper/cache --name=populate --rw=write --bs=4k \ --direct=1 --size=64k 4. Resume the inactive table. Now it's possible to load the dirty block into passthrough mode. dmsetup resume cache Fix by moving the checks to the preresume phase to support table preloading. Also remove the unused function dm_cache_metadata_all_clean.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS