CVE-2026-92521

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ACPI: PCI: Clear driver_data on all paths that free the acpi_pci_root

acpi_pci_root_add() assigns the freshly allocated root to

device->driver_data before dmar_device_add() and pci_acpi_scan_root().

Both failure paths reach the end: label where root is kfree()'d, but

only the pci_acpi_scan_root() path clears driver_data first.

When dmar_device_add() fails during a hot-add, root is freed while

device->driver_data still points at it. The ACPI core does not clear

driver_data on attach failure, so a later acpi_pci_find_root() call may

dereference this dangling pointer.

acpi_pci_root_remove() has the same problem: it frees root without

clearing device->driver_data, leaving a dangling pointer behind after

the root bridge is removed.

Move the NULL assignment to the shared end: label so every error path in

acpi_pci_root_add() clears driver_data before freeing root, and clear it

in acpi_pci_root_remove() as well, so the o

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References