Linux Kernel up to 7.2.9/7.3-rc5 Serial Core serial_core_unregister_port port_dev null pointer dereference

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 7.2.9/7.3-rc5. Impacted is the function serial_core_unregister_port of the component Serial Core. The manipulation of the argument port_dev results in null pointer dereference. This vulnerability was named CVE-2026-98747. The attack needs to be approached locally. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2.9/7.3-rc5. It has been classified as critical. Affected is the function serial_core_unregister_port of the component Serial Core. The manipulation of the argument port_dev with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-98747 since 09/25/2026. The exploitability is told to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

Upgrading to version 7.2.10 or 7.3-rc6 eliminates this vulnerability. Applying the patch 54abbb862366dcaf1f22f1e968358147b7d0547d/499485a67fbacf4d9afbdb43522388c64f853428 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.5
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.9
• 7.3-rc1
• 7.3-rc2
• 7.3-rc3
• 7.3-rc4
• 7.3-rc5

License

• open-source

Website

• Vendor: https://www.kernel.org/

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