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FKIE_CVE-2026-80800

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: 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).
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0cfbdb0e13ab5b0765d77f96af67eb879cbc9736
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1964addc8dd535a05d5d3b55b4d1ac19ae31aa65
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/22e5177ba1196a0b272a6a46c2575eb940a939c4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/389986fd79e4d43f971a03b512645a1bb63c982f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/65a0ec7783b06068dda6745dd689bf4a91ee64aa
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e18d044bab6d3d0280639098c3fe6621692cbfe2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e87527b506c40db9af528714b7b1240918eb80fc
Impacted products
Vendor Product Version
To clipboard 

{
  "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": "b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "e18d044bab6d3d0280639098c3fe6621692cbfe2",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "65a0ec7783b06068dda6745dd689bf4a91ee64aa",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "1964addc8dd535a05d5d3b55b4d1ac19ae31aa65",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "389986fd79e4d43f971a03b512645a1bb63c982f",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "e87527b506c40db9af528714b7b1240918eb80fc",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "22e5177ba1196a0b272a6a46c2575eb940a939c4",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "0cfbdb0e13ab5b0765d77f96af67eb879cbc9736",
              "status": "affected",
              "version": "d646960f7986fefb460a2b062d5ccc8ccfeacc3a",
              "versionType": "git"
            },
            {
              "lessThan": "55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8",
              "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: bound the connect_sn TLV walk to the skb\n\nCommit 27256cdb290e (\"nfc: llcp: bound SNL TLV parsing to the skb and\nadd length checks\") fixed the unbounded TLV walk in nfc_llcp_recv_snl(),\nand commit d8bd2dedbde5 (\"nfc: llcp: fix OOB read and u8 offset wrap in\nTLV parsers\") subsequently bounded nfc_llcp_parse_gb_tlv() and\nnfc_llcp_parse_connection_tlv(). One sibling parser sharing the same\npattern remains unbounded: nfc_llcp_connect_sn().\n\nnfc_llcp_connect_sn() walks a TLV list, reading a two-byte header\n(type, length) followed by length bytes of value, without checking that\nthe two header bytes or the declared length stay within the buffer. It\nreturns a pointer to a service name of up to 255 bytes that may point\npast the end of the skb; it is subsequently consumed by memcmp() in\nnfc_llcp_sock_from_sn(). In addition tlv_array_len was computed as\n\"skb-\u003elen - LLCP_HEADER_SIZE\" in size_t, so a CONNECT/CC frame shorter\nthan the LLCP header underflows to a huge length and the walk runs far\npast the buffer.\n\nnfc_llcp_connect_sn() is reachable from nfc_llcp_recv_connect() and\nnfc_llcp_recv_cc(), i.e. from received CONNECT and CC PDUs. A nearby\nNFC device can reach this without authentication; LLCP link activation\nhappens automatically after NFC-DEP, and the nfc_llcp_rx_skb()\ndispatcher applies no minimum-length guard.\n\nWalk the TLV list by pointer, bounded by skb_tail_pointer(skb), and\nvalidate each declared length before use, matching the approach already\nused for nfc_llcp_recv_snl(). Starting the walk at\n\u0026skb-\u003edata[LLCP_HEADER_SIZE] against the tail pointer also removes the\nsize_t underflow for short frames.\n\nFound by 0sec automated security-research tooling (https://0sec.ai)."
    }
  ],
  "id": "CVE-2026-80800",
  "lastModified": "2026-09-04T16:18:06.797",
  "metrics": {},
  "published": "2026-09-04T16:18:06.797",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0cfbdb0e13ab5b0765d77f96af67eb879cbc9736"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1964addc8dd535a05d5d3b55b4d1ac19ae31aa65"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/22e5177ba1196a0b272a6a46c2575eb940a939c4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/389986fd79e4d43f971a03b512645a1bb63c982f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/55c68ac93e7dacc0f5f608b9c39dd4ff48cf28e8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/65a0ec7783b06068dda6745dd689bf4a91ee64aa"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b2ebdfe3d5b76e91f267a61cbc3f9a0e3f77071e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e18d044bab6d3d0280639098c3fe6621692cbfe2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e87527b506c40db9af528714b7b1240918eb80fc"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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