CVEvulnerability
CVE-2026-80799
- Status
- Received
- Published
- 2026-09-04
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
In the Linux kernel, the following vulnerability has been resolved:
nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers
nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv() contain
three related bugs in their TLV parsing loops:
1. 'offset' is declared u8 but tlv_array_len is u16. When TLV data
advances offset past 255 it silently wraps to zero, causing
infinite loops or double-processing of buffer data.
2. Before reading tlv[0] (type) and tlv[1] (length) there is no
check that offset+2 <= tlv_array_len. A truncated TLV causes
an OOB read of one byte past the buffer end.
3. After reading the length field, the value bytes are accessed
without checking offset+2+length <= tlv_array_len. A crafted
length=0xFF on a short buffer causes up to 255 bytes of OOB
read past the buffer end.
Both functions are reachable without authentication via
nfc_llcp_set_remote_gb() which feeds remote LLCP general bytes
directly into nfc_llcp_parse_gb_tlv() with no additional
validation.
Fix all three issues by widening offset from u8 to u16 and adding
bounds checks for both the TLV header and value field before each
access.
References
- https://git.kernel.org/stable/c/2c1456fe09ab1a5a9fe1d8339ca6d509589b56e1 git.kernel.org
- https://git.kernel.org/stable/c/2d239590d1845a706304833d40dd6d4fec20ad88 git.kernel.org
- https://git.kernel.org/stable/c/382eaa770335acf4f16a5a55524500f2bb4207df git.kernel.org
- https://git.kernel.org/stable/c/78b20c8eeacd2e44a2d8a4cb5316d3c521d90911 git.kernel.org
- https://git.kernel.org/stable/c/7f6f3d087c67a4346189ef2c36481455bbc59a74 git.kernel.org
- https://git.kernel.org/stable/c/875285a165fd3b402de2ab3be0deb355d6f4caf5 git.kernel.org
- https://git.kernel.org/stable/c/9c47d667963542c3cf8e3007b7f10c0904d08238 git.kernel.org
- https://git.kernel.org/stable/c/a209334ed929941b20810c17c3a507445b0a7c85 git.kernel.org
- https://git.kernel.org/stable/c/e84cdfdc4a6c88e8b751144458f2e04e24415a28 git.kernel.org