Description
In the Linux kernel, the following vulnerability has been resolved: sched/eevdf: Prevent vlag from going out of bounds in reweight_eevdf() It was possible to have pick_eevdf() return NULL, which then causes a NULL-deref. This turned out to be due to entity_eligible() returning falsely negative because of a s64 multiplcation overflow. Specifically, reweight_eevdf() computes the vlag without considering the limit placed upon vlag as update_entity_lag() does, and then the scaling multiplication (remember that weight is 20bit fixed point) can overflow. This then leads to the new vruntime being weird which then causes the above entity_eligible() to go side-ways and claim nothing is eligible. Thus limit the range of vlag accordingly. All this was quite rare, but fatal when it does happen.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
14204acc09f652169baed1141c671429047b1313 to < 470d347b14b0ecffa9b39cf8f644fa2351db3efbaffectedeab03c23c2a162085b13200d7942fc5a00b5ccc8 to < 06f27e6d7bf0abf54488259ef36bbf0e1fccb35caffectedeab03c23c2a162085b13200d7942fc5a00b5ccc8 to < 1560d1f6eb6b398bddd80c16676776c0325fe5feaffected6.6.4 to < 6.6.30affected
Linux Linux
Default version status: affected
6.7affected0 to < 6.7unaffected6.6.30 to ≤ 6.6.*unaffected6.8.9 to ≤ 6.8.*unaffected6.9 to ≤ *unaffected