CVE-2026-46034

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux848e447e000c41894ff931dc7c004fd42c8840f8 < 51bf7638f33aece41cb3f4cbeb942cc52950e329affected
LinuxLinux848e447e000c41894ff931dc7c004fd42c8840f8 < 5d6c349c9823eb819fed8b537b088cf38126018caffected
LinuxLinux848e447e000c41894ff931dc7c004fd42c8840f8 < 338a736aaf15e8ba3635ce20b29af5b8fc15e66aaffected
LinuxLinux848e447e000c41894ff931dc7c004fd42c8840f8 < 5ea5880764cbb164afb17a62e76ca75dc371409daffected
LinuxLinux6.10affected
LinuxLinux0 < 6.10unaffected
LinuxLinux6.12.86 <= 6.12.*unaffected
LinuxLinux6.18.27 <= 6.18.*unaffected
LinuxLinux7.0.4 <= 7.0.*unaffected
LinuxLinux7.1 <= *unaffected

Weaknesses

References