CVE Catalog

CVE-2026-97480

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the function serial8250_register_8250_port() has a NULL dereference vulnerability when both the existing uart slot and up have a NULL ->dev. The code only checks if up->port.dev is non-NULL, but then unconditionally calls has_acpi_companion(uart->port.dev), leading to a NULL dereference and kernel crash.

Risk Assessment

The vulnerability can cause a kernel panic in systems with 8250 port registration without a parent device, resulting in system downtime.

Recommendation

Apply the kernel patch that adds a NULL check before calling has_acpi_companion, or update the kernel to a version containing the fix.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: tty: serial: 8250: protect against NULL uart->port.dev in register serial8250_register_8250_port() conditionally copies uart->port.dev from up->port.dev only when up->port.dev is non-NULL: if (up->port.dev) { uart->port.dev = up->port.dev; ... } So if both the existing uart slot and up have a NULL ->dev, uart->port.dev remains NULL. The very next ACPI companion check then dereferences it unconditionally: if (!has_acpi_companion(uart->port.dev)) { has_acpi_companion() reads dev->fwnode without a NULL guard (include/linux/acpi.h), so this NULL-derefs the kernel for the remaining no-dev case rather than just skipping the mctrl_gpio_init() initialisation as intended. smatch flags the inconsistency: drivers/tty/serial/8250/8250_core.c:767 serial8250_register_8250_port() error: 'uart->port.dev' could be null (see line 719) Guard the call with a NULL check so register continues to work for callers that legitimately have no parent device (legacy non-OF/non-ACPI registrations). No functional change for callers that pass a non-NULL ->dev.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS