{"id":"CVE-2026-80798","summary":"nfc: llcp: reject PDUs shorter than the LLCP header","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfc: llcp: reject PDUs shorter than the LLCP header\n\nEvery LLCP PDU begins with a two-byte header (DSAP/SSAP + PTYPE), but the\nreceive path never checked that a frame is at least LLCP_HEADER_SIZE bytes\nbefore parsing it.\n\nnfc_llcp_rx_skb() reads the header via nfc_llcp_ptype()/nfc_llcp_dsap()/\nnfc_llcp_ssap(), which dereference pdu-\u003edata[0] and pdu-\u003edata[1], and a\nCONNECT or CC PDU then computes\n\n\ttlv_array_len = skb-\u003elen - LLCP_HEADER_SIZE;\n\nas a size_t and hands it to the TLV walk. When the frame is shorter than\nthe header the subtraction wraps to a huge value and the walk runs far\npast the buffer, an out-of-bounds read.\n\nA nearby NFC device can reach this without authentication; LLCP link\nactivation happens automatically after NFC-DEP.\n\nGuard the common receive choke point __nfc_llcp_recv(), shared by both the\ntarget (nfc_llcp_data_received()) and initiator (nfc_llcp_recv()) paths, so\na short skb is dropped before the rx_work worker parses it. Use\npskb_may_pull() rather than a skb-\u003elen test so the two header bytes are\nguaranteed to sit in the skb linear area even for a non-linear skb,\nmatching how the sibling NCI and HCI receive paths validate their headers.\n\nReproduced with a KFENCE out-of-bounds read via /dev/virtual_nci on\nlinux-next.\n\nFound by 0sec automated security-research tooling (https://0sec.ai).","modified":"2026-09-06T03:46:46.157167006Z","published":"2026-09-04T15:13:12.282Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80798.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3793d768b40f38bb97265dd5b9a8b8655c4e1b1d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/95674f506c6376d6722a23144c9acd26609771ed"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a7b9b449f5a5132221fff6adc11a9431ab8cd914"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ae5f20f5842f440b72d030e3a34fe182dd8eae42"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d3d90243393c48146911c67fd3792b549d21d9e6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e969e98410051b1ef8cc318bfe0c7e3f24ec766d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eab47618e282602197db287ecbd1b09d356a2515"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f36cffea24bf3e2cc29a00d4b51dbcadc087d810"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80798.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80798"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a"},{"fixed":"e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82"},{"fixed":"f36cffea24bf3e2cc29a00d4b51dbcadc087d810"},{"fixed":"a7b9b449f5a5132221fff6adc11a9431ab8cd914"},{"fixed":"3793d768b40f38bb97265dd5b9a8b8655c4e1b1d"},{"fixed":"eab47618e282602197db287ecbd1b09d356a2515"},{"fixed":"e969e98410051b1ef8cc318bfe0c7e3f24ec766d"},{"fixed":"ae5f20f5842f440b72d030e3a34fe182dd8eae42"},{"fixed":"d3d90243393c48146911c67fd3792b549d21d9e6"},{"fixed":"95674f506c6376d6722a23144c9acd26609771ed"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80798.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.3.0"},{"fixed":"5.10.267"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.218"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.185"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.154"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.106"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.47"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.11"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.2.0"},{"fixed":"7.2.1"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80798.json"}}],"schema_version":"1.9.0"}