nfc: llcp: reject PDUs shorter than the LLCP header
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).
CVE-2026-80798
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-80798
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "f36cffea24bf3e2cc29a00d4b51dbcadc087d810",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "a7b9b449f5a5132221fff6adc11a9431ab8cd914",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "3793d768b40f38bb97265dd5b9a8b8655c4e1b1d",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "eab47618e282602197db287ecbd1b09d356a2515",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "e969e98410051b1ef8cc318bfe0c7e3f24ec766d",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "ae5f20f5842f440b72d030e3a34fe182dd8eae42",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "d3d90243393c48146911c67fd3792b549d21d9e6",
"versionType": "git"
},
{
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"lessThan": "95674f506c6376d6722a23144c9acd26609771ed",
"versionType": "git"
}
],
"programFiles": [
"net/nfc/llcp_core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.267",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.218",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.185",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.154",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.106",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.47",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.11",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2.1",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/nfc/llcp_core.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-80798
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #34815 · Revision 1
- Added to Heist Feed
- Publisher date