CVE-2025-37815: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-37815 is a vulnerability discovered in the Linux kernel, specifically affecting the IRQ handler registration in the Microchip PCI1xxxx driver. The vulnerability was disclosed on May 8, 2025, and affects various Linux distributions including Ubuntu and Debian systems (NVD, Ubuntu Security).

The vulnerability involves a kernel panic condition that occurs during IRQ handler registration in the Microchip PCI1xxxx driver. The issue stems from improper handling of interrupt requests, specifically when accessing the IRQ handler associated with generated IRQs. The vulnerability has been assigned a CVSS v3.1 Base Score of 5.5 with the vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, indicating a moderate severity level (Red Hat).

The vulnerability can result in a kernel panic, potentially causing system instability and denial of service. The impact is primarily focused on system availability, with no direct effect on confidentiality or integrity. The CVSS scoring indicates that while the vulnerability requires local access, it can cause high impact to system availability (Red Hat).

The vulnerability has been resolved through a patch that modifies the IRQ handler registration process. The fix involves acquiring the spinlock and properly storing the current interrupt state before handling the interrupt request using generichandleirq. This replaces a previous attempted fix that used handlenestedirq, which was found to cause additional kernel panic issues (NVD).