CVE-2026-90221

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing

nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse

the CORE_INIT_RSP packet without validating that the skb contains

enough data. A malformed response (e.g. injected via virtual_ncidev)

can declare a large num_supported_rf_interfaces while providing

insufficient data, causing reads of uninitialized slab memory. This

is later used in nci_init_complete_req(), triggering a KMSAN

uninit-value warning.

Add skb length checks before accessing packet fields:

- Validate the skb has at least 1 byte for the status field.

- Validate the skb can hold the fixed-size header before parsing.

- In v2, bounds-check each variable-length rf_interface entry and its

extension parameters within the parsing loop.

- In v1, verify the skb is large enough for both the variable-length

rf_interfaces array and the trailing rsp_2 structure.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References