net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check

{
  "id": "756e768339547ecb1ec4113c348324878ce5b457d7a0203b772e79560e56dab7",
  "url": "https://osv.dev/vulnerability/CVE-2026-98278",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: remove WARN_ON_ONCE() from the dev_fill_forward_path() loop check ipip_fill_forward_path() and ip6_tnl_fill_forward_path() look up the route to the tunnel's remote endpoint and set ctx->dev to its device, which is the tunnel itself when that route resolves back to the tunnel. dev_fill_forward_path() then makes no progress and trips WARN_ON_ONCE(last_dev == ctx->dev) as soon as a flowtable tries to offload a flow through the tunnel. That routing loop is a configuration any CAP_NET_ADMIN user can set up, and ip_tunnel_xmit() and ip6_tnl_xmit() already treat it as a tx error, so remove the warning and just fail the walk, as commit 008e7a7c293b (\"net: remove WARN_ON_ONCE when accessing forward path array\") did for the path stack overflow.",
    "evidence": "osv:CVE-2026-98278",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.2.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98278",
      "aliases": [
        "CVE-2026-98278"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ab427db17885814069bae891834f20842f0ac3a4"
                },
                {
                  "fixed": "d8eb177632dacda28bc6130c2105afbf5b791eb0"
                },
                {
                  "fixed": "150dba2c69e93302af24a0c868eebe4871e2e107"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98278.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.8"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98278.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:41.207592271Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/150dba2c69e93302af24a0c868eebe4871e2e107",
        "https://git.kernel.org/stable/c/d8eb177632dacda28bc6130c2105afbf5b791eb0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98278.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98278",
        "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-2026-98278.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98278",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 509117,
  "published_at": "2026-10-06T08:45:38.346+00:00"
}