pfcp: fix socket lifetime on netdevice registration failure

{
  "id": "ee2e5c1db9da8dd9a7f34e1270d7f6454052b5b25dd395be19a87753e7e98333",
  "url": "https://osv.dev/vulnerability/CVE-2026-98849",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "pfcp: fix socket lifetime on netdevice registration failure",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: pfcp: fix socket lifetime on netdevice registration failure pfcp_newlink() creates the UDP socket before register_netdevice(). If registration fails after pfcp_dev_init() succeeds, the core calls pfcp_dev_uninit(), which releases the socket and clears pfcp->sk. The newlink error path then releases it again, causing a NULL pointer dereference. This was observed with failslab fault injection: FAULT_INJECTION: forcing a failure. kobject: kobject_add_internal failed for pfcp0 (error: -12 parent: net) BUG: KASAN: null-ptr-deref in udp_tunnel_sock_release+0x1c/0x50 Read of size 8 at addr 0000000000000120 by task ip/1037 Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x78/0x90 print_report+0x468/0x5cc kasan_report+0xa4/0xf0 __asan_load8+0x7c/0xd0 udp_tunnel_sock_release+0x1c/0x50 pfcp_newlink+0x128/0x184 rtnl_newlink+0x848/0xe44 rtnetlink_rcv_msg+0x468/0x514 netlink_rcv_skb+0xc0/0x1f0 rtnetlink_rcv+0x18/0x24 netlink_unicast+0x4b8/0x558 netlink_sendmsg+0x2b8/0x584 ... Return from pfcp_del_sock() if pfcp->sk is NULL.",
    "evidence": "osv:CVE-2026-98849",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "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-2026-98849",
      "aliases": [
        "CVE-2026-98849"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "76c8764ef36a5d37ea2e551bda28ac7f028383ba"
                },
                {
                  "fixed": "dcb8f6a79c3360a440c399d85df465a6e59351f1"
                },
                {
                  "fixed": "4b8ce1686dea1a10805a0807bf492409b0300ee1"
                },
                {
                  "fixed": "2cee3603ec1d9b5ec7f2121ea3efe9488e906f46"
                },
                {
                  "fixed": "0f17d2e3dd9cda3ee6d94033d5e5489af168920d"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98849.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.10.0"
                },
                {
                  "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"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98849.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.122265949Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0f17d2e3dd9cda3ee6d94033d5e5489af168920d",
        "https://git.kernel.org/stable/c/2cee3603ec1d9b5ec7f2121ea3efe9488e906f46",
        "https://git.kernel.org/stable/c/4b8ce1686dea1a10805a0807bf492409b0300ee1",
        "https://git.kernel.org/stable/c/dcb8f6a79c3360a440c399d85df465a6e59351f1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98849.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98849",
        "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-2026-98849.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98849",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 491707,
  "published_at": "2026-10-18T15:50:48.743+00:00"
}