nfc: llcp: drop truncated I/RR/RNR PDUs in nfc_llcp_recv_hdlc()

{
  "id": "fcd560536c0d79ad009c340f0137e6765a796b197c22ece528c45a4131d61ec4",
  "url": "https://osv.dev/vulnerability/CVE-2026-98482",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "nfc: llcp: drop truncated I/RR/RNR PDUs in nfc_llcp_recv_hdlc()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: nfc: llcp: drop truncated I/RR/RNR PDUs in nfc_llcp_recv_hdlc() nfc_llcp_recv_hdlc() reads the sequence byte skb->data[2], via nfc_llcp_ns()/nfc_llcp_nr(), before any length check. The receive path only guarantees the two-byte LLCP header -- __nfc_llcp_recv() checks it with pskb_may_pull() and nfc_llcp_recv_agf() admits two-byte inner PDUs -- so a two-byte I, RR or RNR PDU reads one byte of uninitialised skb tailroom. The byte becomes N(R)/N(S); a peer can already set those with a well-formed PDU, so this is acting on uninitialised memory, not new peer control. Guard the read with pskb_may_pull(), as commit 95674f506c63 (\"nfc: llcp: reject PDUs shorter than the LLCP header\") did for the two-byte header, so the sequence byte is present and linear before it is read. RR and RNR PDUs are LLCP_HEADER_SIZE + LLCP_SEQUENCE_SIZE bytes and an I PDU is longer, so no valid frame is rejected; a truncated PDU is malformed, so return without a DM reply.",
    "evidence": "osv:CVE-2026-98482",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.271",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.222",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.189",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.158",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.112",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.55",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98482",
      "aliases": [
        "CVE-2026-98482"
      ],
      "affected": [
        {
          "ranges": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
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                {
                  "fixed": "3afdbebfee2ef7e9510880868cfb482cbffe6836"
                },
                {
                  "fixed": "9b4086eb67a9a3b1ce69fef1b6793827363703ce"
                },
                {
                  "fixed": "51b6d73373589abb9de4d84767b0db1bc8d395d9"
                },
                {
                  "fixed": "066205553a0106565bcede934f5721c25ebd6e4e"
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                {
                  "fixed": "18f60ee882403d5b48097f5f6ae45f794e4cc643"
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                  "fixed": "810f204ef8f61f0c930cf6b3280050b3ee6a8ae7"
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          "database_specific": {
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          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
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                {
                  "introduced": "3.3.0"
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                {
                  "fixed": "5.10.271"
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            {
              "type": "ECOSYSTEM",
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                {
                  "introduced": "5.11.0"
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                {
                  "fixed": "5.15.222"
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98482.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.566138291Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/066205553a0106565bcede934f5721c25ebd6e4e",
        "https://git.kernel.org/stable/c/18f60ee882403d5b48097f5f6ae45f794e4cc643",
        "https://git.kernel.org/stable/c/273f9d667cde649f8de9d72b1303cc2f4b658c50",
        "https://git.kernel.org/stable/c/3afdbebfee2ef7e9510880868cfb482cbffe6836",
        "https://git.kernel.org/stable/c/51b6d73373589abb9de4d84767b0db1bc8d395d9",
        "https://git.kernel.org/stable/c/744e61bd06188d8bb068c26a461c252f242b05c9",
        "https://git.kernel.org/stable/c/810f204ef8f61f0c930cf6b3280050b3ee6a8ae7",
        "https://git.kernel.org/stable/c/9b4086eb67a9a3b1ce69fef1b6793827363703ce",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98482.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98482",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98482.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98482",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 490192,
  "published_at": "2026-10-18T15:15:56.227+00:00"
}