nfc: llcp: bound the connect_sn TLV walk to the skb
Summary
| CVE | CVE-2026-80800 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-04 16:18:06 UTC |
| Updated | 2026-09-04 16:18:06 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: bound the connect_sn TLV walk to the skb Commit 27256cdb290e ("nfc: llcp: bound SNL TLV parsing to the skb and add length checks") fixed the unbounded TLV walk in nfc_llcp_recv_snl(), and commit d8bd2dedbde5 ("nfc: llcp: fix OOB read and u8 offset wrap in TLV parsers") subsequently bounded nfc_llcp_parse_gb_tlv() and nfc_llcp_parse_connection_tlv(). One sibling parser sharing the same pattern remains unbounded: nfc_llcp_connect_sn(). nfc_llcp_connect_sn() walks a TLV list, reading a two-byte header (type, length) followed by length bytes of value, without checking that the two header bytes or the declared length stay within the buffer. It returns a pointer to a service name of up to 255 bytes that may point past the end of the skb; it is subsequently consumed by memcmp() in nfc_llcp_sock_from_sn(). In addition tlv_array_len was computed as "skb->len - LLCP_HEADER_SIZE" in size_t, so a CONNECT/CC frame shorter than the LLCP header underflows to a huge length and the walk runs far past the buffer. nfc_llcp_connect_sn() is reachable from nfc_llcp_recv_connect() and nfc_llcp_recv_cc(), i.e. from received CONNECT and CC PDUs. A nearby NFC device can reach this without authentication; LLCP link activation happens automatically after NFC-DEP, and the nfc_llcp_rx_skb() dispatcher applies no minimum-length guard. Walk the TLV list by pointer, bounded by skb_tail_pointer(skb), and validate each declared length before use, matching the approach already used for nfc_llcp_recv_snl(). Starting the walk at &skb->data[LLCP_HEADER_SIZE] against the tail pointer also removes the size_t underflow for short frames. Found by 0sec automated security-research tooling (https://0sec.ai). |
Risk And Classification
EPSS: 0.002340000 probability, percentile 0.142160000 (date 2026-09-07)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a e18d044bab6d3d0280639098c3fe6621692cbfe2 git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a 65a0ec7783b06068dda6745dd689bf4a91ee64aa git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a 1964addc8dd535a05d5d3b55b4d1ac19ae31aa65 git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a 389986fd79e4d43f971a03b512645a1bb63c982f git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a e87527b506c40db9af528714b7b1240918eb80fc git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a 22e5177ba1196a0b272a6a46c2575eb940a939c4 git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a 0cfbdb0e13ab5b0765d77f96af67eb879cbc9736 git | Not specified |
| CNA | Linux | Linux | affected d646960f7986fefb460a2b062d5ccc8ccfeacc3a 55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8 git | Not specified |
| CNA | Linux | Linux | affected 3.3 | Not specified |
| CNA | Linux | Linux | unaffected 3.3 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.267 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.218 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.185 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.154 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.106 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.47 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.11 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.1 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/22e5177ba1196a0b272a6a46c2575eb940a939c4 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e18d044bab6d3d0280639098c3fe6621692cbfe2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e87527b506c40db9af528714b7b1240918eb80fc | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/1964addc8dd535a05d5d3b55b4d1ac19ae31aa65 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/65a0ec7783b06068dda6745dd689bf4a91ee64aa | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/389986fd79e4d43f971a03b512645a1bb63c982f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0cfbdb0e13ab5b0765d77f96af67eb879cbc9736 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.