CVE-2021-47257

What it actually does

Logic error in IEEE 802.15.4 device address parsing that allows a null pointer dereference when the address mode is set incorrectly for the supplied address type.

Why it matters to the business

May cause kernel crashes and denial of service on Linux systems that use IEEE 802.15.4 wireless networking; low remote exploitability reduces immediate risk but still requires attention on affected devices.

How an attack unfolds

An attacker supplies an IEEE 802.15.4 address configuration with mismatched mode and type values, causing the parsing routine to dereference a null pointer and trigger a kernel fault.

How to fix it

Update the Linux kernel to a version containing the fix for the ieee802154 address parsing logic error.

How to confirm the fix worked

Confirm the running kernel includes the resolved ieee802154 parse logic, then attempt address configuration with deliberately mismatched mode and type values to verify no dereference occurs.

Typical attack path

1. Identify systems running vulnerable Linux kernel versions with IEEE 802.15.4 support
2. Obtain sufficient privileges to configure or send address parameters to the ieee802154 stack
3. Craft address data with incorrect mode relative to address type
4. Trigger the parse path to induce the null dereference and system instability

How to detect it

Search kernel logs and crash dumps for null pointer dereference faults occurring inside ieee802154 address parsing functions after address configuration attempts.

What your security team should do

• Prioritize kernel updates on any systems exposing IEEE 802.15.4 interfaces
• Restrict configuration access to ieee802154 devices to trusted processes only
• Monitor kernel logs for oops or panic entries referencing ieee802154 address parsing