{"id":"CVE-2026-97480","published":"2026-09-24T17:17:25.467","lastModified":"2026-09-28T06:16:34.003","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.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/5cbab666721d974bfe033a12045d808936deaefd","tags":[]},{"url":"https://git.kernel.org/stable/c/941c9f84c9b6310f7aaa1c8c785dcc634ee33050","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":null}