{"id":"CVE-2026-90315","summary":"PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers","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]","modified":"2026-09-18T03:48:37.771809563Z","published":"2026-09-17T16:08:34.218Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90315.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/747b9bbbbdfdee51aee2456388f9b94b5086de4d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cd07aef510ac6a2873e01f9ddddc5492490b0067"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90315.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90315"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"eb627e17727ebeede70697ae1798688b0d328b54"},{"fixed":"cd07aef510ac6a2873e01f9ddddc5492490b0067"},{"fixed":"747b9bbbbdfdee51aee2456388f9b94b5086de4d"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90315.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.4.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90315.json"}}],"schema_version":"1.9.0"}