The Linux kernel vulnerability CVE-2026-64458 involves the damon_hot_score() function in the mm/damon/ops-common component. The function mishandled extreme user-configured monitoring intervals: zero sampling intervals caused divide-by-zero errors in damon_max_nr_accesses(), zero aggregation intervals led to incorrect zero returns and subsequent divide-by-zero in damon_hot_score(), and very high aggregation intervals caused out-of-bounds array access in regions_score_histogram. These issues could cause kernel panics or crashes. The fix explicitly handles zero intervals in damon_max_nr_accesses() and clamps damon_hot_score() return values within the valid range [0, DAMOS_MAX_SCORE].

Improper handling of zero or extremely high monitoring intervals in damon_hot_score() can cause divide-by-zero errors and out-of-bounds memory access, resulting in kernel crashes (Oops). This can lead to denial of service on affected Linux systems if exploited by writing specific values to sysfs monitoring attributes.

A fix has been applied in the Linux kernel to address these issues by properly handling zero intervals and bounding return values. Users should update to a Linux kernel version that includes this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply them accordingly.