CVE-2025-39909

/// Technical description

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

mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters()

Patch series "mm/damon: avoid divide-by-zero in DAMON module's parameters

application".

DAMON's RECLAIM and LRU_SORT modules perform no validation on

user-configured parameters during application, which may lead to

division-by-zero errors.

Avoid the divide-by-zero by adding validation checks when DAMON modules

attempt to apply the parameters.

This patch (of 2):

During the calculation of 'hot_thres' and 'cold_thres', either

'sample_interval' or 'aggr_interval' is used as the divisor, which may

lead to division-by-zero errors. Fix it by directly returning -EINVAL

when such a case occurs. Additionally, since 'aggr_interval' is already

required to be set no smaller than 'sample_interval' in damon_set_attrs(),

only the case where 'sample_interval' is zero needs to be checked.

/// 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