CVE-2026-80867: alpha/PCI: Add security_locked_down() check to pci_mmap_resource()
In the Linux kernel, the following vulnerability has been resolved:
alpha/PCI: Add securitylockeddown() check to pcimmapresource()
Currently, Alpha's pcimmapresource() does not check securitylockeddown(LOCKDOWNPCIACCESS) before allowing userspace to mmap PCI BARs.
The generic version has had this check since commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked down") to prevent DMA attacks when the kernel is locked down.
Add the same check to Alpha's pcimmapresource().
Affected Software
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
The issue affects Linux kernel systems running on the Alpha architecture, where the Alpha-specific pci_mmap_resource() implementation is used. Other architectures are not identified as affected by the provided information.
What must an attacker be able to do to exploit it?
An attacker needs userspace access sufficient to request an mmap of a PCI BAR. The risk is specifically that access to PCI BARs can enable DMA attacks even while kernel lockdown is active.
Is a locked-down kernel configuration affected?
Yes. The missing LOCKDOWN_PCI_ACCESS check means Alpha systems could permit userspace PCI BAR mappings despite kernel lockdown, defeating the intended restriction on BAR access.
What is the remediation?
Update to a Linux kernel containing the Alpha-specific security_locked_down(LOCKDOWN_PCI_ACCESS) check in pci_mmap_resource(). The referenced stable kernel commits contain the fix.