Description
In the Linux kernel, the following vulnerability has been resolved:
PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers
Currently, the legacy I/O and memory sysfs handlers do not check
security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and
legacy_mem files unprotected when the kernel is locked down.
Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked
down") added the check to pci_write_config(), pci_mmap_resource(), and
pci_write_resource_io() to prevent userspace from programming DMA-capable
hardware that could be used to modify kernel code, but did not cover the
legacy handlers.
As a result, root can still write arbitrary I/O ports and map the legacy
I/O and memory spaces while the kernel is locked down, which is the same
capability the lockdown is meant to remove.
Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and
pci_mmap_legacy_io().
These generic handlers cover both architectures that define HAVE_PCI_LEGACY
(such as Alpha and PowerPC).
[bhelgaas: add Link]
PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers
Currently, the legacy I/O and memory sysfs handlers do not check
security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and
legacy_mem files unprotected when the kernel is locked down.
Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked
down") added the check to pci_write_config(), pci_mmap_resource(), and
pci_write_resource_io() to prevent userspace from programming DMA-capable
hardware that could be used to modify kernel code, but did not cover the
legacy handlers.
As a result, root can still write arbitrary I/O ports and map the legacy
I/O and memory spaces while the kernel is locked down, which is the same
capability the lockdown is meant to remove.
Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and
pci_mmap_legacy_io().
These generic handlers cover both architectures that define HAVE_PCI_LEGACY
(such as Alpha and PowerPC).
[bhelgaas: add Link]
Published:
2026-09-17
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers Currently, the legacy I/O and memory sysfs handlers do not check security_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and legacy_mem files unprotected when the kernel is locked down. Commit eb627e17727e ("PCI: Lock down BAR access when the kernel is locked down") added the check to pci_write_config(), pci_mmap_resource(), and pci_write_resource_io() to prevent userspace from programming DMA-capable hardware that could be used to modify kernel code, but did not cover the legacy handlers. As a result, root can still write arbitrary I/O ports and map the legacy I/O and memory spaces while the kernel is locked down, which is the same capability the lockdown is meant to remove. Add the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and pci_mmap_legacy_io(). These generic handlers cover both architectures that define HAVE_PCI_LEGACY (such as Alpha and PowerPC). [bhelgaas: add Link] | |
| Title | PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:08:34.218Z
Reserved: 2026-09-11T19:38:34.801Z
Link: CVE-2026-90315
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:29.340
Modified: 2026-09-17T17:17:29.340
Link: CVE-2026-90315
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.