{"id":"CVE-2026-90315","published":"2026-09-17T17:17:29.340","lastModified":"2026-09-17T17:17:29.340","description":"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]","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/747b9bbbbdfdee51aee2456388f9b94b5086de4d","tags":[]},{"url":"https://git.kernel.org/stable/c/cd07aef510ac6a2873e01f9ddddc5492490b0067","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}