The bug causes the Altera PCI host driver to register a chained IRQ handler during probe without properly removing it when the probe fails. The handler and the associated INTx IRQ domain remain configured even after the driver’s devm‑managed storage is freed, leaving a stale data pointer. Because interrupts were enabled before probing, failing after that point leaves the controller interrupt source active. This results in resource leaks, dangling pointers, and potentially undefined behavior that can lead to kernel instability or denial of service, exemplifying CWE-825.

The vulnerability affects the Altera PCI host driver in the Linux kernel. All Linux systems running an affected kernel where the Altera PCI device is present are impacted. The specific kernel version and release are not specified, but the fix is present in the commit series linked in the references.

The EPSS score is below 1% and the vulnerability is not listed in CISA KEV, indicating a low likelihood of exploitation. No remote attack vector is described; based on the description, it is inferred that an exploit would require a local privilege failure during PCI device probing. The lack of a public exploit and low EPSS suggest that the risk to most installations is minimal, though an unstable system could occur if a probe failure leaves persistent IRQ handlers.