GHSA-7FPW-G7P7-53QH
Vulnerability from github – Published: 2026-09-17 18:32 – Updated: 2026-10-15 12:30In 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]
{
"affected": [],
"aliases": [
"CVE-2026-90315"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-17T17:17:29Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nPCI/sysfs: Add lockdown checks to legacy I/O and memory handlers\n\nCurrently, the legacy I/O and memory sysfs handlers do not check\nsecurity_locked_down(LOCKDOWN_PCI_ACCESS), leaving the legacy_io and\nlegacy_mem files unprotected when the kernel is locked down.\n\nCommit eb627e17727e (\"PCI: Lock down BAR access when the kernel is locked\ndown\") added the check to pci_write_config(), pci_mmap_resource(), and\npci_write_resource_io() to prevent userspace from programming DMA-capable\nhardware that could be used to modify kernel code, but did not cover the\nlegacy handlers.\n\nAs a result, root can still write arbitrary I/O ports and map the legacy\nI/O and memory spaces while the kernel is locked down, which is the same\ncapability the lockdown is meant to remove.\n\nAdd the same check to pci_write_legacy_io(), pci_mmap_legacy_mem(), and\npci_mmap_legacy_io().\n\nThese generic handlers cover both architectures that define HAVE_PCI_LEGACY\n(such as Alpha and PowerPC).\n\n[bhelgaas: add Link]",
"id": "GHSA-7fpw-g7p7-53qh",
"modified": "2026-10-15T12:30:50Z",
"published": "2026-09-17T18:32:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90315"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3556caa31a2bfbc22c11b812fd4ed8851c2d7bff"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/747b9bbbbdfdee51aee2456388f9b94b5086de4d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cd07aef510ac6a2873e01f9ddddc5492490b0067"
}
],
"schema_version": "1.4.0",
"severity": []
}
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