CVE-2026-99240

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> mm/damon/core: error damos_commit_quota_goal() for zero target_value<br /> <br /> Patch series "mm/damon: move zero damos quota target_value handling to the<br /> core layer".<br /> <br /> Having zero DAMOS quota target value can cause division by zero. DAMON<br /> API callers are checking the target value parameters to avoid that. It is<br /> easy to make mistakes in some of the multiple API callers. Move that to<br /> the core layer.<br /> <br /> Patch 1 adds the corner case handling into the core layer DAMON parameters<br /> validation logic. Patches 2 and 3 remove no more needed DAMON API callers<br /> side handling of the corner case in DAMON_LRU_SORT and DMON_SAMPLIE_MTIER,<br /> respectively.<br /> <br /> <br /> This patch (of 3):<br /> <br /> If a DAMOS scheme has a damos_quota_goal of zero target_value,<br /> damos_quota_goal() could trigger division-by-zero error. Hence each DAMON<br /> API callers should do the zero target_value validation. It is easy to<br /> make mistakes. Actually such bugs in DAMON_LRU_SORT and<br /> DAMON_SAMPLE_MTIER were found and fixed [1].<br /> <br /> It is better to handle the corner case only once in the core layer,<br /> instead of multiple places in all DAMON API callers. One straightforward<br /> option is using an alternative denominator for the corner case in the<br /> damos_quota_goal(). However, the zero target_value is meaningless. In<br /> this case, the quota goal is always evaluated as achieved or<br /> over-achieved. The quota will only keep being reduced.<br /> <br /> Simply avoid using zero target_value by adding a check in the core layer<br /> DAMOS quota goal parameters validation/commit path,<br /> damos_commit_quota_goal(). Update it to return an error in the case. <br /> Also update its caller to propagate the error.