{"id":"CVE-2026-97480","title":"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->…","summary":"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->…","severity":"medium","vendor":"Linux","product":"Linux","affected":["Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 5cbab666721d974bfe033a12045d808936deaefd","Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 941c9f84c9b6310f7aaa1c8c785dcc634ee33050","Linux < 6.18.53","Linux (all versions)"],"published":"2026-09-24","updated":"2026-09-28","sourceUpdated":"2026-09-28T06:16:34.003","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-97480","references":[{"url":"https://git.kernel.org/stable/c/5cbab666721d974bfe033a12045d808936deaefd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/941c9f84c9b6310f7aaa1c8c785dcc634ee33050","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97480.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-97480"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2540447"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97480"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97480"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97480.mbox"},{"url":"https://git.kernel.org/stable/c/68059b6e9f7292714286e2b0f5185ed2a43fccc5"},{"url":"https://git.kernel.org/stable/c/9c78f89cf2fbae18b14c78bf172ca15d832aff15"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00174,"epssPercentile":0.06844,"ingestedAt":"2026-09-24T16:47:15.871Z","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-476"],"slug":"CVE-2026-97480","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97480.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":213465,"id":"CVE-2026-97480","ts":1790754733750,"field":"cvss","old":null,"new":"5.5"},{"seq":213464,"id":"CVE-2026-97480","ts":1790754733750,"field":"severity","old":"none","new":"medium"}]}