Linux Kernel CVE-2026-72143

The affected component is the platform/x86: ISST (Intel Speed Select Technology) driver subsystem in the Linux kernel. Intel SST is a feature present on server-class Intel Xeon processors (e.g., Ice Lake-SP, Sapphire Rapids) that allows selection of CPU performance profiles (SST-PP) per power domain - distinct voltage and frequency regions within a multi-die package. During the PM suspend path, the driver correctly iterates all power domains using pd_info->sst_base to save their SST-PP control register values. However, the resume restore path erroneously uses power_domain_info->sst_base, which is a fixed pointer to power domain 0's MMIO base address. As a result, the restore loop writes domain 0's values into what it believes are the other domains' registers, but actually writes back to domain 0's address space, leaving domains 1 through N-1 in whatever transient hardware state exists post-resume. No CWE was formally assigned, but the root cause is a classic wrong-variable logic error in symmetric save/restore code - the save path uses the per-domain iterator while the restore path references a static global. The fix replaces power_domain_info->sst_base with pd_info->sst_base in the restore loop.