CVE-2026-46034
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel that allows for a NULL pointer dereference in the interrupt trigger path. This issue has been resolved by adding validation to ensure that MSI is configured before accessing the cdx_irqs array.
Risk Assessment
The lack of proper validation may lead to application crashes in user space, threatening system stability. An attacker could exploit this vulnerability to trigger unforeseen system behaviors.
Recommendation
It is recommended to update the Linux kernel to the latest version to eliminate this vulnerability. Additionally, monitor the interrupt configuration in the system to ensure proper setup.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: vfio/cdx: Fix NULL pointer dereference in interrupt trigger path Add validation to ensure MSI is configured before accessing cdx_irqs array in vfio_cdx_set_msi_trigger(). Without this check, userspace can trigger a NULL pointer dereference by calling VFIO_DEVICE_SET_IRQS with VFIO_IRQ_SET_DATA_BOOL or VFIO_IRQ_SET_DATA_NONE flags before ever setting up interrupts via VFIO_IRQ_SET_DATA_EVENTFD. The vfio_cdx_msi_enable() function allocates the cdx_irqs array and sets config_msi to 1 only when called through the EVENTFD path. The trigger loop (for DATA_BOOL/DATA_NONE) assumed this had already been done, but there was no enforcement of this call ordering. This matches the protection used in the PCI VFIO driver where vfio_pci_set_msi_trigger() checks irq_is() before the trigger loop.