netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP

{
  "id": "86067dbd39276c15e316c691eb3fa32f5745711ab36b349e6c60f3722fe8c508",
  "url": "https://osv.dev/vulnerability/CVE-2026-31424",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for NFPROTO_ARP Weiming Shi says: xt_match and xt_target structs registered with NFPROTO_UNSPEC can be loaded by any protocol family through nft_compat. When such a match/target sets .hooks to restrict which hooks it may run on, the bitmask uses NF_INET_* constants. This is only correct for families whose hook layout matches NF_INET_*: IPv4, IPv6, INET, and bridge all share the same five hooks (PRE_ROUTING ... POST_ROUTING). ARP only has three hooks (IN=0, OUT=1, FORWARD=2) with different semantics. Because NF_ARP_OUT == 1 == NF_INET_LOCAL_IN, the .hooks validation silently passes for the wrong reasons, allowing matches to run on ARP chains where the hook assumptions (e.g. state->in being set on input hooks) do not hold. This leads to NULL pointer dereferences; xt_devgroup is one concrete example: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227] RIP: 0010:devgroup_mt+0xff/0x350 Call Trace: nft_match_eval (net/netfilter/nft_compat.c:407) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_arp (net/netfilter/nft_chain_filter.c:61) nf_hook_slow (net/netfilter/core.c:623) arp_xmit (net/ipv4/arp.c:666) Kernel panic - not syncing: Fatal exception in interrupt Fix it by restricting arptables to NFPROTO",
    "evidence": "osv:CVE-2026-31424",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.253",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.203",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.168",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.134",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.81",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.22",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.12",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-31424",
      "aliases": [
        "CVE-2026-31424"
      ],
      "affected": [
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              "type": "GIT",
              "events": [
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                {
                  "fixed": "d9a0af9e43416aa50c0595e15fa01365a1c72c49"
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                {
                  "fixed": "1cd6313c8644bfebbd813a05da9daa21b09dd68c"
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                {
                  "fixed": "f00ac65c90ea475719e08d629e2e26c8b4e6999b"
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                {
                  "fixed": "e7e1b6bcb389c8708003d40613a59ff2496f6b1f"
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                  "fixed": "dc3e27dd7d76e21106b8f9bbdc31f5da74a89014"
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                  "fixed": "3d5d488f11776738deab9da336038add95d342d1"
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            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31424.json"
          }
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        {
          "ranges": [
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              "type": "ECOSYSTEM",
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                  "introduced": "2.6.39"
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31424.json"
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      ],
      "modified": "2026-10-28T02:30:26.443883149Z",
      "provider": "osv",
      "references": [
        "https://cert-portal.siemens.com/productcert/html/ssa-019113.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-082556.html",
        "https://cert-portal.siemens.com/productcert/html/ssa-457936.html",
        "https://git.kernel.org/stable/c/1cd6313c8644bfebbd813a05da9daa21b09dd68c",
        "https://git.kernel.org/stable/c/3d5d488f11776738deab9da336038add95d342d1",
        "https://git.kernel.org/stable/c/3e79374b03bf9a2f282f0eb1d0ac3776f7e0f28a",
        "https://git.kernel.org/stable/c/80e3c75f71c3ea1e62fcb032382de13e00a68f8b",
        "https://git.kernel.org/stable/c/d9a0af9e43416aa50c0595e15fa01365a1c72c49",
        "https://git.kernel.org/stable/c/dc3e27dd7d76e21106b8f9bbdc31f5da74a89014",
        "https://git.kernel.org/stable/c/e7e1b6bcb389c8708003d40613a59ff2496f6b1f",
        "https://git.kernel.org/stable/c/f00ac65c90ea475719e08d629e2e26c8b4e6999b",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31424.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31424",
        "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/2026/31xxx/CVE-2026-31424.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31424",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 492721,
  "published_at": "2026-04-13T13:40:27.957+00:00"
}