Linux Kernel EUVD-2026-32391

The vulnerability resides in the Linux kernel's thermal/of subsystem (thermal/of.c), which uses Open Firmware Device Tree (DT) phandle resolution to look up thermal cooling maps on embedded and ARM-class platforms. The of_parse_phandle() kernel API returns a struct device_node pointer with an incremented reference count; callers must explicitly call of_node_put() to release it, or use scope-based cleanup. In thermal_of_cm_lookup(), the returned tr_np pointer was never released, creating a reference leak on every invocation of the lookup. The fix applies the __free(device_node) cleanup attribute, a kernel-internal RAII-style mechanism that automatically invokes of_node_put() when tr_np exits scope. While no CWE was formally assigned, this maps to CWE-772 (Missing Release of Resource after Effective Lifetime). CPE data confirms affected scope as cpe:2.3:o:linux:linux_kernel across multiple stable branches spanning from the introducing commit 423de5b5bc5b through the respective fix commits. The 'Information Disclosure' tag in the metadata is inconsistent with CVSS C:N and the technical description and appears erroneous.