CVE-2026-43344

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> perf/x86/intel/uncore: Fix die ID init and look up bugs<br /> <br /> In snbep_pci2phy_map_init(), in the nr_node_ids &gt; 8 path,<br /> uncore_device_to_die() may return -1 when all CPUs associated<br /> with the UBOX device are offline.<br /> <br /> Remove the WARN_ON_ONCE(die_id == -1) check for two reasons:<br /> <br /> - The current code breaks out of the loop. This is incorrect because<br /> pci_get_device() does not guarantee iteration in domain or bus order,<br /> so additional UBOX devices may be skipped during the scan.<br /> <br /> - Returning -EINVAL is incorrect, since marking offline buses with<br /> die_id == -1 is expected and should not be treated as an error.<br /> <br /> Separately, when NUMA is disabled on a NUMA-capable platform,<br /> pcibus_to_node() returns NUMA_NO_NODE, causing uncore_device_to_die()<br /> to return -1 for all PCI devices. As a result,<br /> spr_update_device_location(), used on Intel SPR and EMR, ignores the<br /> corresponding PMON units and does not add them to the RB tree.<br /> <br /> Fix this by using uncore_pcibus_to_dieid(), which retrieves topology<br /> from the UBOX GIDNIDMAP register and works regardless of whether NUMA<br /> is enabled in Linux. This requires snbep_pci2phy_map_init() to be<br /> added in spr_uncore_pci_init().<br /> <br /> Keep uncore_device_to_die() only for the nr_node_ids &gt; 8 case, where<br /> NUMA is expected to be enabled.