CVE-2026-64462 addresses a resource leak in the Linux kernel's PCI Altera driver. The vulnerability arises because the chained IRQ handler is installed during the probe phase but only removed during driver removal. If pci_host_probe() fails, the handler and INTx IRQ domain remain active despite the release of the associated host bridge storage, leaving the handler with a stale pointer. Additionally, interrupts are enabled before pci_host_probe() is called, and if the probe fails after this point, the interrupt source is not disabled properly. The fix involves setting the chained handler only after the INTx domain is created, disabling controller interrupts during IRQ teardown, and tearing down IRQ setup if pci_host_probe() fails.

If pci_host_probe() fails, the chained IRQ handler and interrupt domain remain set with stale pointers, potentially leading to resource leaks and unstable interrupt handling in the kernel. This could cause system instability or crashes related to interrupt processing in the affected PCI Altera driver.

A fix has been implemented in the Linux kernel to address this issue. Users should update to a Linux kernel version that includes this patch. Since this is a kernel-level fix, applying the official kernel update from the vendor or distribution is the recommended remediation. Patch status is not explicitly stated here; check the vendor advisory or Linux kernel mailing lists for the specific fixed version.