Linux Kernel PCI Endpoint Test Interrupt Handling Vulnerability

A vulnerability in the Linux kernel's PCI endpoint test module can lead to improper interrupt management. When the function 'devm_request_irq()' fails, the subsequent call to 'pci_endpoint_test_free_irq_vectors()' incorrectly assumes that all interrupts have been released. This oversight leaves some interrupts unacknowledged, causing residual entries in '/proc/irq/*' that trigger a warning about removing a non-empty directory, indicating a leak of IRQ information. The vulnerability arises from the failure to properly manage interrupt requests, which can lead to inconsistencies in the IRQ handling process.

Impact

Exploitation of this vulnerability can cause a warning message to be generated, indicating a failure to properly clean up interrupt requests, which could potentially be exploited to interfere with the normal operation of the system's interrupt handling.

Remediation

The vulnerability has been addressed by modifying the interrupt handling process to correctly release IRQs before freeing them, ensuring that no residual entries are left in the IRQ management system. Users should apply the latest patches available in the Linux kernel to mitigate this issue.