[PATCH net 0/2] nfc: llcp: fix OOB reads and integer bugs in TLV parsers

[Muhammad Bilal]

This series fixes memory safety bugs in the NFC LLCP TLV parsing code,
reachable from a remote NFC peer via crafted LLCP frames.

Patch 1 fixes nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv():
  - u8 offset wraps to zero after 255 (widened to u16)
  - OOB read of TLV header on truncated buffer
  - OOB read of value field via attacker-controlled length byte

Patch 2 fixes nfc_llcp_recv_snl():
  - OOB read of TLV header when tlv_len - offset == 1
  - OOB read of SDREQ value via attacker-controlled length
  - SIZE_MAX underflow when length == 0 in service_name_len,
    bypassing the sn_len == 0 guard in nfc_llcp_sock_from_sn()

Previously reported to security@xxxxxxxxxx on 2026-05-15. Willy Tarreau
advised posting to public lists as NFC is currently orphaned.

Muhammad Bilal (2):
  nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers
  nfc: llcp: add missing bounds checks in nfc_llcp_recv_snl()

 net/nfc/llcp_commands.c | 28 ++++++++++++++++++++++++++--
 net/nfc/llcp_core.c     | 23 +++++++++++++++++++++--
 2 files changed, 47 insertions(+), 4 deletions(-)

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2.54.0