CVE-2026-90221nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing

Official 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/baed3fdf6ed2195c56f25ae18a086b938dcd3983
• https://git.kernel.org/stable/c/2f434478771a4ebdd535033561c0590bcde39753
• https://git.kernel.org/stable/c/5487f04c1ccbfa15aa6e531eb1ec9c9ec9c7bf31
• https://git.kernel.org/stable/c/bbe68e8249e2c76d65adfd9224fa95f1ca0fbe4e
• https://git.kernel.org/stable/c/4f0483bbcdaccc9d4aee30df7351863334cecfa7
• https://git.kernel.org/stable/c/7d44b897bff84edcd4814899314d661ad4956a8e
• https://git.kernel.org/stable/c/d56575a2595ee1f597f39e8a1cfb67ed3501678d