CVE-2026-68259

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

drm/amdkfd: Check bounds in allocate_event_notification_slot

The valid event ids go from 0 to KFD_SIGNAL_EVENT_LIMIT

allocate_event_notification_slot has an option to specify
an event id to allocate at, used by CRIU. We weren't checking
the bounds on that value.

Check them.

v2: Lower bounds check is unecessary because of idr_alloc
already rejecting negative numbers. Upper bounds check should
be KFD_SIGNAL_EVENT_LIMIT since the signal mode mappings might
not yet exist

(cherry picked from commit 6853f1f6cbbeb3f53ebbbd7286536aeb2c5d5f50)