{"id":"CVE-2026-80798","state":"PUBLISHED","title":"nfc: llcp: reject PDUs shorter than the LLCP header","description":"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->data[0] and pdu->data[1], and a\nCONNECT or CC PDU then computes\n\n\ttlv_array_len = skb->len - 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->len 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).","publishedAt":"2026-09-04T15:13:12.282Z","updatedAt":"2026-10-19T08:43:51.441Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"f36cffea24bf3e2cc29a00d4b51dbcadc087d810","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"a7b9b449f5a5132221fff6adc11a9431ab8cd914","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"3793d768b40f38bb97265dd5b9a8b8655c4e1b1d","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"eab47618e282602197db287ecbd1b09d356a2515","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"e969e98410051b1ef8cc318bfe0c7e3f24ec766d","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"ae5f20f5842f440b72d030e3a34fe182dd8eae42","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"d3d90243393c48146911c67fd3792b549d21d9e6","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"95674f506c6376d6722a23144c9acd26609771ed","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/nfc/llcp_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.3","versionType":"semver"},{"version":"5.10.267","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.218","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.185","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.154","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.106","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.47","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.11","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.1","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/nfc/llcp_core.c"]}],"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"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80798.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80798","state":"PUBLISHED","datePublished":"2026-09-04T15:13:12.282Z","dateUpdated":"2026-10-19T08:43:51.441Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.793Z"},"containers":{"cna":{"title":"nfc: llcp: reject PDUs shorter than the LLCP header","descriptions":[{"lang":"en","value":"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->data[0] and pdu->data[1], and a\nCONNECT or CC PDU then computes\n\n\ttlv_array_len = skb->len - 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->len 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)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"f36cffea24bf3e2cc29a00d4b51dbcadc087d810","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"a7b9b449f5a5132221fff6adc11a9431ab8cd914","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"3793d768b40f38bb97265dd5b9a8b8655c4e1b1d","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"eab47618e282602197db287ecbd1b09d356a2515","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"e969e98410051b1ef8cc318bfe0c7e3f24ec766d","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"ae5f20f5842f440b72d030e3a34fe182dd8eae42","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"d3d90243393c48146911c67fd3792b549d21d9e6","versionType":"git"},{"version":"d646960f7986fefb460a2b062d5ccc8ccfeacc3a","status":"affected","lessThan":"95674f506c6376d6722a23144c9acd26609771ed","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/nfc/llcp_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.3","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.3","versionType":"semver"},{"version":"5.10.267","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.218","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.185","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.154","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.106","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.47","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.11","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.1","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/nfc/llcp_core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82"},{"url":"https://git.kernel.org/stable/c/f36cffea24bf3e2cc29a00d4b51dbcadc087d810"},{"url":"https://git.kernel.org/stable/c/a7b9b449f5a5132221fff6adc11a9431ab8cd914"},{"url":"https://git.kernel.org/stable/c/3793d768b40f38bb97265dd5b9a8b8655c4e1b1d"},{"url":"https://git.kernel.org/stable/c/eab47618e282602197db287ecbd1b09d356a2515"},{"url":"https://git.kernel.org/stable/c/e969e98410051b1ef8cc318bfe0c7e3f24ec766d"},{"url":"https://git.kernel.org/stable/c/ae5f20f5842f440b72d030e3a34fe182dd8eae42"},{"url":"https://git.kernel.org/stable/c/d3d90243393c48146911c67fd3792b549d21d9e6"},{"url":"https://git.kernel.org/stable/c/95674f506c6376d6722a23144c9acd26609771ed"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:43:51.441Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.10.267"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"5.15.218"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.1.185"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.6.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.12.106"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"6.18.47"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"7.1.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"7.2.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.3","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}