ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel()

{
  "id": "f25c5036423ed4cda9baf56217239f2050e988ed7fad0ae9cf160e880203dce6",
  "url": "https://osv.dev/vulnerability/CVE-2026-98934",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: use skb_get_hash_net() in seg6_make_flowlabel() Since commit d58e468b1112 (\"flow_dissector: implements flow dissector BPF hook\") __skb_flow_dissect() needs a net pointer, either from skb->dev, skb->sk, or since commit 3cbf4ffba5ee (\"net: plumb network namespace into __skb_flow_dissect\") a caller provided pointer. syzbot was able to reach seg6_make_flowlabel() with an skb having neither skb->dev nor skb->sk set: a TIPC UDP bearer sends a discovery message through an IPv4 route using seg6 encap, while net.ipv6.seg6_flowlabel is set to 1. seg6_make_flowlabel() already has a net pointer, use skb_get_hash_net(). WARNING: net/core/flow_dissector.c:1131 at __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126, CPU#0: syz.0.17/4930 Call trace: __skb_flow_dissect+0x910/0x5368 net/core/flow_dissector.c:1126 (P) __skb_get_hash_net+0xe0/0x29c net/core/flow_dissector.c:1903 skb_get_hash include/linux/skbuff.h:1663 [inline] seg6_make_flowlabel+0xcc/0x1ec net/ipv6/seg6_iptunnel.c:132 __seg6_do_srh_encap+0x320/0xbf4 net/ipv6/seg6_iptunnel.c:161 seg6_do_srh+0x4b4/0xa44 net/ipv6/seg6_iptunnel.c:431 seg6_output_core+0x164/0x688 net/ipv6/seg6_iptunnel.c:681 seg6_output+0x44/0x1ac net/ipv6/seg6_iptunnel.c:744 lwtunnel_output+0x3d0/0x664 net/core/lwtunnel.c:356 dst_output include/net/dst.h:470 [inline] ip_local_out+0x110/0x148 net/ipv4/ip_output.c:131 iptunnel_xmit+0x50c/0xd38 net/ipv4/ip_tunnel_core.c:97 udp_tu",
    "evidence": "osv:CVE-2026-98934",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.273",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.224",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.191",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.160",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.113",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.56",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98934",
      "aliases": [
        "CVE-2026-98934"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "d58e468b1112dcd1d5193c0a89ff9f98b5a3e8b9"
                },
                {
                  "fixed": "de83419b5062a6f83bb9421be77cae734cbead65"
                },
                {
                  "fixed": "8407a2c1aa67c2a110a576df8f82a4e259188b82"
                },
                {
                  "fixed": "a43d96620d080b1b2324a53e38dd7b4bff4825c1"
                },
                {
                  "fixed": "4ab37e4f4a33c64d9e565dc8c4c3ed774f05c0e3"
                },
                {
                  "fixed": "8fe3d6717f5536793727e60b7a0b7ec20c697def"
                },
                {
                  "fixed": "53b21bc2df6e8ed538bceda93a5104a5fe6a8a84"
                },
                {
                  "fixed": "086e8acb3a0e55f6d22d29fae2a4a3b1561bb766"
                },
                {
                  "fixed": "8ec454dcd00ce3375119111c6394964455b36d0d"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98934.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.20.0"
                },
                {
                  "fixed": "5.10.273"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.224"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.191"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.160"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.113"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.56"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.10"
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              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98934.json"
          }
        }
      ],
      "modified": "2026-11-01T02:30:15.843416745Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/086e8acb3a0e55f6d22d29fae2a4a3b1561bb766",
        "https://git.kernel.org/stable/c/4ab37e4f4a33c64d9e565dc8c4c3ed774f05c0e3",
        "https://git.kernel.org/stable/c/53b21bc2df6e8ed538bceda93a5104a5fe6a8a84",
        "https://git.kernel.org/stable/c/8407a2c1aa67c2a110a576df8f82a4e259188b82",
        "https://git.kernel.org/stable/c/8ec454dcd00ce3375119111c6394964455b36d0d",
        "https://git.kernel.org/stable/c/8fe3d6717f5536793727e60b7a0b7ec20c697def",
        "https://git.kernel.org/stable/c/a43d96620d080b1b2324a53e38dd7b4bff4825c1",
        "https://git.kernel.org/stable/c/de83419b5062a6f83bb9421be77cae734cbead65",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98934.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98934",
        "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-2026-98934.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98934",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 499258,
  "published_at": "2026-10-23T12:11:43.459+00:00"
}