CVE-2026-89443

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

platform/x86: ISST: Validate level in perf mask ioctls

isst if get perf level mask() and isst if get base freq mask() use the user-provided level as an index into perf levels[] via read pp level info() and read bf level info(), but neither helper validates it first.

The adjacent level-info helpers reject levels above max level before reading the same per-level register block. Add the same bounds checks to the mask helpers, and reject disabled SST-PP levels in isst if get perf level mask() to match isst if get perf level info().

This prevents out-of-bounds reads from the per-level offset table on invalid ioctl input.