Linux Kernel EUVD-2026-28678

This vulnerability affects the Linux kernel's Distributed Switch Architecture (DSA) subsystem, specifically the Microchip KSZ switch driver's Precision Time Protocol (PTP) interrupt handling code. The affected component is responsible for setting up threaded interrupt handlers for PTP message processing in Microchip network switches. When the request_threaded_irq() kernel API call fails during initialization, the code path fails to call irq_dispose_mapping() for the newly created IRQ domain mapping, violating the kernel's resource management contract. This results in IRQ descriptor leakage within the kernel's IRQ subsystem. The vulnerability was introduced in commit d0b8fec8ae50 and affects kernel versions from 6.6 through 6.19 and the 7.0 development tree. CPE identifiers confirm impact across the entire Linux kernel product line during the affected version window. The root cause is improper resource cleanup in error handling paths, a common pattern in kernel driver initialization code where multiple resource allocations occur sequentially and partial failure scenarios must unwind correctly.