Description
In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: reject PDUs shorter than the LLCP header Every LLCP PDU begins with a two-byte header (DSAP/SSAP + PTYPE), but the receive path never checked that a frame is at least LLCP_HEADER_SIZE bytes before parsing it. nfc_llcp_rx_skb() reads the header via nfc_llcp_ptype()/nfc_llcp_dsap()/ nfc_llcp_ssap(), which dereference pdu->data[0] and pdu->data[1], and a CONNECT or CC PDU then computes tlv_array_len = skb->len - LLCP_HEADER_SIZE; as a size_t and hands it to the TLV walk. When the frame is shorter than the header the subtraction wraps to a huge value and the walk runs far past the buffer, an out-of-bounds read. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP. Guard the common receive choke point __nfc_llcp_recv(), shared by both the target (nfc_llcp_data_received()) and initiator (nfc_llcp_recv()) paths, so a short skb is dropped before the rx_work worker parses it. Use pskb_may_pull() rather than a skb->len test so the two header bytes are guaranteed to sit in the skb linear area even for a non-linear skb, matching how the sibling NCI and HCI receive paths validate their headers. Reproduced with a KFENCE out-of-bounds read via /dev/virtual_nci on linux-next. Found by 0sec automated security-research tooling (https://0sec.ai).
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
d646960f7986fefb460a2b062d5ccc8ccfeacc3a to < e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82affectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < f36cffea24bf3e2cc29a00d4b51dbcadc087d810affectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < a7b9b449f5a5132221fff6adc11a9431ab8cd914affectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < 3793d768b40f38bb97265dd5b9a8b8655c4e1b1daffectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < eab47618e282602197db287ecbd1b09d356a2515affectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < e969e98410051b1ef8cc318bfe0c7e3f24ec766daffectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < ae5f20f5842f440b72d030e3a34fe182dd8eae42affectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < d3d90243393c48146911c67fd3792b549d21d9e6affectedd646960f7986fefb460a2b062d5ccc8ccfeacc3a to < 95674f506c6376d6722a23144c9acd26609771edaffected
Linux Linux
Default version status: affected
3.3affected0 to < 3.3unaffected5.10.267 to ≤ 5.10.*unaffected5.15.218 to ≤ 5.15.*unaffected6.1.185 to ≤ 6.1.*unaffected6.6.154 to ≤ 6.6.*unaffected6.12.106 to ≤ 6.12.*unaffected6.18.47 to ≤ 6.18.*unaffected7.1.11 to ≤ 7.1.*unaffected7.2.1 to ≤ 7.2.*unaffected7.3 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82 ↗
- https://git.kernel.org/stable/c/f36cffea24bf3e2cc29a00d4b51dbcadc087d810 ↗
- https://git.kernel.org/stable/c/a7b9b449f5a5132221fff6adc11a9431ab8cd914 ↗
- https://git.kernel.org/stable/c/3793d768b40f38bb97265dd5b9a8b8655c4e1b1d ↗
- https://git.kernel.org/stable/c/eab47618e282602197db287ecbd1b09d356a2515 ↗
- https://git.kernel.org/stable/c/e969e98410051b1ef8cc318bfe0c7e3f24ec766d ↗
- https://git.kernel.org/stable/c/ae5f20f5842f440b72d030e3a34fe182dd8eae42 ↗
- https://git.kernel.org/stable/c/d3d90243393c48146911c67fd3792b549d21d9e6 ↗
- https://git.kernel.org/stable/c/95674f506c6376d6722a23144c9acd26609771ed ↗