{"id":"CVE-2026-90315","title":"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_ACC…","summary":"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_ACC…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= eb627e17727ebeede70697ae1798688b0d328b54 < cd07aef510ac6a2873e01f9ddddc5492490b0067","Linux >= eb627e17727ebeede70697ae1798688b0d328b54 < 747b9bbbbdfdee51aee2456388f9b94b5086de4d","Linux 5.4"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:29.340","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90315","references":[{"url":"https://git.kernel.org/stable/c/747b9bbbbdfdee51aee2456388f9b94b5086de4d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cd07aef510ac6a2873e01f9ddddc5492490b0067","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.825Z","epss":0.00189,"epssPercentile":0.0882,"slug":"CVE-2026-90315","body":"## Overview\n\nIn 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]\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}