CVE-2025-39909

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/lru_sort: avoid divide-by-zero in damon_lru_sort_apply_parameters()<br /> <br /> Patch series "mm/damon: avoid divide-by-zero in DAMON module&amp;#39;s parameters<br /> application".<br /> <br /> DAMON&amp;#39;s RECLAIM and LRU_SORT modules perform no validation on<br /> user-configured parameters during application, which may lead to<br /> division-by-zero errors.<br /> <br /> Avoid the divide-by-zero by adding validation checks when DAMON modules<br /> attempt to apply the parameters.<br /> <br /> <br /> This patch (of 2):<br /> <br /> During the calculation of &amp;#39;hot_thres&amp;#39; and &amp;#39;cold_thres&amp;#39;, either<br /> &amp;#39;sample_interval&amp;#39; or &amp;#39;aggr_interval&amp;#39; is used as the divisor, which may<br /> lead to division-by-zero errors. Fix it by directly returning -EINVAL<br /> when such a case occurs. Additionally, since &amp;#39;aggr_interval&amp;#39; is already<br /> required to be set no smaller than &amp;#39;sample_interval&amp;#39; in damon_set_attrs(),<br /> only the case where &amp;#39;sample_interval&amp;#39; is zero needs to be checked.