In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers nfc_llcp_par

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.