Linux CVE-2026-90221

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.