CVE Catalog

CVE-2026-80800

Unknown
Published: Translated: NVD NIST

Summary

A vulnerability was found in the Linux kernel's nfc_llcp_connect_sn() TLV parser in the NFC LLCP subsystem. The parser fails to check buffer boundaries when reading TLV headers and values, leading to out-of-bounds reads or infinite loops due to length underflow for short frames. The issue is remotely reachable by a nearby NFC device without authentication.

Risk Assessment

An attacker with a nearby NFC device can trigger unauthorized kernel memory reads, potentially exposing sensitive data or causing system instability (e.g., kernel panic). Since no authentication is required and LLCP link activation is automatic, the risk is significant in environments with NFC enabled.

Recommendation

Apply the official Linux kernel patch that bounds the TLV walk to the skb tail pointer and validates declared lengths before use. Also consider disabling NFC if not needed and monitor distribution security advisories.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: bound the connect_sn TLV walk to the skb Commit 27256cdb290e ("nfc: llcp: bound SNL TLV parsing to the skb and add length checks") fixed the unbounded TLV walk in nfc_llcp_recv_snl(), and commit d8bd2dedbde5 ("nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers") subsequently bounded nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv(). One sibling parser sharing the same pattern remains unbounded: nfc_llcp_connect_sn(). nfc_llcp_connect_sn() walks a TLV list, reading a two-byte header (type, length) followed by length bytes of value, without checking that the two header bytes or the declared length stay within the buffer. It returns a pointer to a service name of up to 255 bytes that may point past the end of the skb; it is subsequently consumed by memcmp() in nfc_llcp_sock_from_sn(). In addition tlv_array_len was computed as "skb->len - LLCP_HEADER_SIZE" in size_t, so a CONNECT/CC frame shorter than the LLCP header underflows to a huge length and the walk runs far past the buffer. nfc_llcp_connect_sn() is reachable from nfc_llcp_recv_connect() and nfc_llcp_recv_cc(), i.e. from received CONNECT and CC PDUs. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP, and the nfc_llcp_rx_skb() dispatcher applies no minimum-length guard. Walk the TLV list by pointer, bounded by skb_tail_pointer(skb), and validate each declared length before use, matching the approach already used for nfc_llcp_recv_snl(). Starting the walk at &skb->data[LLCP_HEADER_SIZE] against the tail pointer also removes the size_t underflow for short frames. Found by 0sec automated security-research tooling (https://0sec.ai).

Vulnerability data from NVD (NIST) · CISA KEV · EPSS