{"id":"CVE-2026-97480","state":"PUBLISHED","title":"tty: serial: 8250: protect against NULL uart->port.dev in register","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntty: serial: 8250: protect against NULL uart->port.dev in register\n\nserial8250_register_8250_port() conditionally copies uart->port.dev\nfrom up->port.dev only when up->port.dev is non-NULL:\n\n\tif (up->port.dev) {\n\t\tuart->port.dev = up->port.dev;\n\t\t...\n\t}\n\nSo if both the existing uart slot and up have a NULL ->dev,\nuart->port.dev remains NULL. The very next ACPI companion check\nthen dereferences it unconditionally:\n\n\tif (!has_acpi_companion(uart->port.dev)) {\n\nhas_acpi_companion() reads dev->fwnode without a NULL guard\n(include/linux/acpi.h), so this NULL-derefs the kernel for the\nremaining no-dev case rather than just skipping the\nmctrl_gpio_init() initialisation as intended.\n\nsmatch flags the inconsistency:\n\n  drivers/tty/serial/8250/8250_core.c:767\n  serial8250_register_8250_port() error: 'uart->port.dev' could be\n  null (see line 719)\n\nGuard the call with a NULL check so register continues to work\nfor callers that legitimately have no parent device (legacy\nnon-OF/non-ACPI registrations).\n\nNo functional change for callers that pass a non-NULL ->dev.","publishedAt":"2026-09-24T16:04:22.893Z","updatedAt":"2026-10-30T12:37:01.897Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"f728f7f38a6eca16923c72fc6826445810d2b41f","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"68059b6e9f7292714286e2b0f5185ed2a43fccc5","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"9c78f89cf2fbae18b14c78bf172ca15d832aff15","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"5cbab666721d974bfe033a12045d808936deaefd","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"941c9f84c9b6310f7aaa1c8c785dcc634ee33050","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/8250/8250_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.3","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/8250/8250_core.c"]}],"references":["https://git.kernel.org/stable/c/f728f7f38a6eca16923c72fc6826445810d2b41f","https://git.kernel.org/stable/c/68059b6e9f7292714286e2b0f5185ed2a43fccc5","https://git.kernel.org/stable/c/9c78f89cf2fbae18b14c78bf172ca15d832aff15","https://git.kernel.org/stable/c/5cbab666721d974bfe033a12045d808936deaefd","https://git.kernel.org/stable/c/941c9f84c9b6310f7aaa1c8c785dcc634ee33050"],"weaknesses":[],"ingestedAt":"2026-10-30T12:56:04.490Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97480.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97480","state":"PUBLISHED","datePublished":"2026-09-24T16:04:22.893Z","dateUpdated":"2026-10-30T12:37:01.897Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-24T16:01:01.149Z"},"containers":{"cna":{"title":"tty: serial: 8250: protect against NULL uart->port.dev in register","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntty: serial: 8250: protect against NULL uart->port.dev in register\n\nserial8250_register_8250_port() conditionally copies uart->port.dev\nfrom up->port.dev only when up->port.dev is non-NULL:\n\n\tif (up->port.dev) {\n\t\tuart->port.dev = up->port.dev;\n\t\t...\n\t}\n\nSo if both the existing uart slot and up have a NULL ->dev,\nuart->port.dev remains NULL. The very next ACPI companion check\nthen dereferences it unconditionally:\n\n\tif (!has_acpi_companion(uart->port.dev)) {\n\nhas_acpi_companion() reads dev->fwnode without a NULL guard\n(include/linux/acpi.h), so this NULL-derefs the kernel for the\nremaining no-dev case rather than just skipping the\nmctrl_gpio_init() initialisation as intended.\n\nsmatch flags the inconsistency:\n\n  drivers/tty/serial/8250/8250_core.c:767\n  serial8250_register_8250_port() error: 'uart->port.dev' could be\n  null (see line 719)\n\nGuard the call with a NULL check so register continues to work\nfor callers that legitimately have no parent device (legacy\nnon-OF/non-ACPI registrations).\n\nNo functional change for callers that pass a non-NULL ->dev."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"f728f7f38a6eca16923c72fc6826445810d2b41f","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"68059b6e9f7292714286e2b0f5185ed2a43fccc5","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"9c78f89cf2fbae18b14c78bf172ca15d832aff15","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"5cbab666721d974bfe033a12045d808936deaefd","versionType":"git"},{"version":"4a96895f74c9633b51427fd080ab70fa62b65bc4","status":"affected","lessThan":"941c9f84c9b6310f7aaa1c8c785dcc634ee33050","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/8250/8250_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.3","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/8250/8250_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f728f7f38a6eca16923c72fc6826445810d2b41f"},{"url":"https://git.kernel.org/stable/c/68059b6e9f7292714286e2b0f5185ed2a43fccc5"},{"url":"https://git.kernel.org/stable/c/9c78f89cf2fbae18b14c78bf172ca15d832aff15"},{"url":"https://git.kernel.org/stable/c/5cbab666721d974bfe033a12045d808936deaefd"},{"url":"https://git.kernel.org/stable/c/941c9f84c9b6310f7aaa1c8c785dcc634ee33050"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:37:01.897Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.3","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}