FKIE_CVE-2026-80798
Vulnerability from fkie_nvd - Published: 2026-09-04 16:18 - Updated: 2026-09-04 16:18
Severity
Summary
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).
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/nfc/llcp_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "f36cffea24bf3e2cc29a00d4b51dbcadc087d810",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "a7b9b449f5a5132221fff6adc11a9431ab8cd914",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "3793d768b40f38bb97265dd5b9a8b8655c4e1b1d",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "eab47618e282602197db287ecbd1b09d356a2515",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "e969e98410051b1ef8cc318bfe0c7e3f24ec766d",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "ae5f20f5842f440b72d030e3a34fe182dd8eae42",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "d3d90243393c48146911c67fd3792b549d21d9e6",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
},
{
"lessThan": "95674f506c6376d6722a23144c9acd26609771ed",
"status": "affected",
"version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/nfc/llcp_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.3"
},
{
"lessThan": "3.3",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.267",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.218",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.185",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.154",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.106",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.47",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.1",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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-\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": "CVE-2026-80798",
"lastModified": "2026-09-04T16:18:06.487",
"metrics": {},
"published": "2026-09-04T16:18:06.487",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/3793d768b40f38bb97265dd5b9a8b8655c4e1b1d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/95674f506c6376d6722a23144c9acd26609771ed"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a7b9b449f5a5132221fff6adc11a9431ab8cd914"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/ae5f20f5842f440b72d030e3a34fe182dd8eae42"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d3d90243393c48146911c67fd3792b549d21d9e6"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/e969e98410051b1ef8cc318bfe0c7e3f24ec766d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/eab47618e282602197db287ecbd1b09d356a2515"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f36cffea24bf3e2cc29a00d4b51dbcadc087d810"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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