CVE-2026-98747
Received Received - Intake

NULL Pointer Dereference in Linux Kernel Serial Core

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: serial: core: fix NULL pointer dereference in serial_core_unregister_port() port->port_dev is NULL when no port device is installed: it is cleared on teardown, and never set if registration failed before serial_core_port_device_add(). serial_core_unregister_port() passes it straight to serial_core_get_ctrl_dev(), which dereferences it: KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] RIP: serial_core_unregister_port Call Trace: serial8250_unregister_port serial8250_remove unbind_store Return early when there is no port device, and read port->port_dev under port_mutex. Also clear port->port_dev on the serial_core_register_port() error path, where the port device has already been removed.

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98747
EUVD
EUVD-2026-103832

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
Linux Linux 84a9582fd203063cd4d301204971ff2cd8327f1a
Linux Linux 84a9582fd203063cd4d301204971ff2cd8327f1a
Linux Linux 6.5

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a NULL pointer dereference vulnerability in the Linux kernel's serial core subsystem. It occurs when serial_core_unregister_port() tries to access port->port_dev which is NULL. This happens if no port device was installed or if registration failed before serial_core_port_device_add(). The issue leads to a kernel crash due to dereferencing a NULL pointer.

Detection Guidance

This vulnerability is specific to the Linux kernel's serial core subsystem and may not have direct network detection methods. Check kernel logs for NULL pointer dereference errors related to serial_core_unregister_port or serial8250_unregister_port using commands like dmesg | grep -i 'null-ptr-deref' or journalctl -k | grep -i 'serial_core'.

Impact Analysis

This vulnerability can cause system instability or crashes when unregistering serial ports. It may lead to denial of service if the affected system becomes unresponsive. Users might experience sudden system failures during operations involving serial port management.

Mitigation Strategies

Update the Linux kernel to a patched version that includes the fix for this issue. Monitor kernel logs for related errors and ensure no serial port devices are in an inconsistent state during unregister operations.

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