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).
- Published
- Sep 4, 2026
- Updated
- Sep 4, 2026
- EPSS
- 0.3% · 19th percentile
- CWE
- —
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Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
Affected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 3.3affected
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82affected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before f36cffea24bf3e2cc29a00d4b51dbcadc087d810affected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before a7b9b449f5a5132221fff6adc11a9431ab8cd914affected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 3793d768b40f38bb97265dd5b9a8b8655c4e1b1daffected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before eab47618e282602197db287ecbd1b09d356a2515affected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before e969e98410051b1ef8cc318bfe0c7e3f24ec766daffected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before ae5f20f5842f440b72d030e3a34fe182dd8eae42affected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before d3d90243393c48146911c67fd3792b549d21d9e6affected · git
- d646960f7986fefb460a2b062d5ccc8ccfeacc3a and later · before 95674f506c6376d6722a23144c9acd26609771edaffected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.187-1 | 6.1.187-1 |
| Debian:12 | linux-6.12 | before 6.12.107-1~deb12u1 | 6.12.107-1~deb12u1 |
| Debian:13 | linux | before 6.12.107-1 | 6.12.107-1 |
| Debian:14 | linux | before 7.1.12-1 | 7.1.12-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 3793d768b40f38bb97265dd5b9a8b8655c4e1b1d | Vendor (CNA) |
| Linux Linux | 95674f506c6376d6722a23144c9acd26609771ed | Vendor (CNA) |
| Linux Linux | a7b9b449f5a5132221fff6adc11a9431ab8cd914 | Vendor (CNA) |
| Linux Linux | ae5f20f5842f440b72d030e3a34fe182dd8eae42 | Vendor (CNA) |
| Linux Linux | d3d90243393c48146911c67fd3792b549d21d9e6 | Vendor (CNA) |
| Linux Linux | e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82 | Vendor (CNA) |
| Linux Linux | e969e98410051b1ef8cc318bfe0c7e3f24ec766d | Vendor (CNA) |
| Linux Linux | eab47618e282602197db287ecbd1b09d356a2515 | Vendor (CNA) |
| Linux Linux | f36cffea24bf3e2cc29a00d4b51dbcadc087d810 | Vendor (CNA) |
| azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 | — | Microsoft (MSRC) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for helpChange log
- Fix✗ → ✓
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References
- git.kernel.org/stable/c/3793d768b40f38bb97265dd5b9a8b8655c4e1b1d
- git.kernel.org/stable/c/95674f506c6376d6722a23144c9acd26609771ed
- git.kernel.org/stable/c/a7b9b449f5a5132221fff6adc11a9431ab8cd914
- git.kernel.org/stable/c/ae5f20f5842f440b72d030e3a34fe182dd8eae42
- git.kernel.org/stable/c/d3d90243393c48146911c67fd3792b549d21d9e6
- git.kernel.org/stable/c/e6ec76a68dce04884dfeccfe5a5f0e9f67c0ec82
- git.kernel.org/stable/c/e969e98410051b1ef8cc318bfe0c7e3f24ec766d
- git.kernel.org/stable/c/eab47618e282602197db287ecbd1b09d356a2515
- git.kernel.org/stable/c/f36cffea24bf3e2cc29a00d4b51dbcadc087d810
Vendor advisories and official records. Exploit/PoC links are deliberately left out.