{"id":"CVE-2026-90315","state":"PUBLISHED","title":"PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers","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]","publishedAt":"2026-09-17T16:08:34.218Z","updatedAt":"2026-10-19T09:01:31.722Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eb627e17727ebeede70697ae1798688b0d328b54","status":"affected","lessThan":"3556caa31a2bfbc22c11b812fd4ed8851c2d7bff","versionType":"git"},{"version":"eb627e17727ebeede70697ae1798688b0d328b54","status":"affected","lessThan":"cd07aef510ac6a2873e01f9ddddc5492490b0067","versionType":"git"},{"version":"eb627e17727ebeede70697ae1798688b0d328b54","status":"affected","lessThan":"747b9bbbbdfdee51aee2456388f9b94b5086de4d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci-sysfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.4","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci-sysfs.c"]}],"references":["https://git.kernel.org/stable/c/3556caa31a2bfbc22c11b812fd4ed8851c2d7bff","https://git.kernel.org/stable/c/cd07aef510ac6a2873e01f9ddddc5492490b0067","https://git.kernel.org/stable/c/747b9bbbbdfdee51aee2456388f9b94b5086de4d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:34.582Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/90xxx/CVE-2026-90315.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-90315","state":"PUBLISHED","datePublished":"2026-09-17T16:08:34.218Z","dateUpdated":"2026-10-19T09:01:31.722Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.801Z"},"containers":{"cna":{"title":"PCI/sysfs: Add lockdown checks to legacy I/O and memory handlers","descriptions":[{"lang":"en","value":"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]"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"eb627e17727ebeede70697ae1798688b0d328b54","status":"affected","lessThan":"3556caa31a2bfbc22c11b812fd4ed8851c2d7bff","versionType":"git"},{"version":"eb627e17727ebeede70697ae1798688b0d328b54","status":"affected","lessThan":"cd07aef510ac6a2873e01f9ddddc5492490b0067","versionType":"git"},{"version":"eb627e17727ebeede70697ae1798688b0d328b54","status":"affected","lessThan":"747b9bbbbdfdee51aee2456388f9b94b5086de4d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci-sysfs.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.4","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.4","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/pci/pci-sysfs.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/3556caa31a2bfbc22c11b812fd4ed8851c2d7bff"},{"url":"https://git.kernel.org/stable/c/cd07aef510ac6a2873e01f9ddddc5492490b0067"},{"url":"https://git.kernel.org/stable/c/747b9bbbbdfdee51aee2456388f9b94b5086de4d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:01:31.722Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}