GHSA-P65W-76HH-QJ57
Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31In 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": [],
"aliases": [
"CVE-2026-80798"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-04T16:18:06Z",
"severity": null
},
"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).",
"id": "GHSA-p65w-76hh-qj57",
"modified": "2026-09-04T18:31:26Z",
"published": "2026-09-04T18:31:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80798"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}
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