Linux Kernel Request_IRQ Vulnerability in VF Misc Interrupt Handling

A vulnerability has been identified in the Linux kernel's handling of virtual function (VF) miscellaneous interrupts within the net: libwx component. The issue arises from the use of request_threaded_irq() with a primary handler and a NULL threaded handler, while also applying the IRQF_ONESHOT flag. This combination triggers a warning, as it violates the expected usage of threaded interrupt handlers. The vulnerability affects several versions of the Linux kernel.

Impact

The vulnerability could lead to improper interrupt handling, potentially causing missed interrupts or incorrect interrupt processing for virtual functions.

Reproduction

The vulnerability can be reproduced by using request_threaded_irq() to handle interrupts for a virtual function without providing a threaded handler, while also setting the IRQF_ONESHOT flag. This will trigger a warning about the incorrect usage of the interrupt request flags.

Remediation

The vulnerability has been addressed by modifying the interrupt handling to use request_irq() instead of request_threaded_irq(), removing the IRQF_ONESHOT flag. Users should apply the latest patches available in the Linux kernel stable tree to mitigate this issue.