can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER

{
  "id": "883adea9b25d3ff72c21bbfcbdbd23750301ceb40ce582455d77a976c2988ab0",
  "url": "https://osv.dev/vulnerability/CVE-2026-72125",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: can: isotp: fix use-after-free race with concurrent NETDEV_UNREGISTER isotp_release() looked up the bound network device via dev_get_by_index() using the stored ifindex. During device unregistration the device is unlisted from the ifindex hash before the NETDEV_UNREGISTER notifier chain runs, so a concurrent isotp_release() could find no device, skip can_rx_unregister() entirely, and still proceed to free the socket. Since isotp_release() had already removed itself from the isotp notifier list at that point, isotp_notify() would never get a chance to clean up either, leaving a stale CAN filter that keeps pointing at the freed socket. Fix this the same way raw.c already does: hold a tracked reference to the bound net_device in the socket (so->dev/so->dev_tracker) from bind() onward instead of re-resolving it from the ifindex, and serialize bind()/release() with rtnl_lock() so that so->dev is always consistent with what the NETDEV_UNREGISTER notifier sees. so->dev stays valid regardless of ifindex-hash unlisting, and is only ever cleared by whichever of isotp_release()/isotp_notify() gets there first, so the filter is always removed exactly once. isotp_bind() now rejects a (re)bind with -EAGAIN while so->[tx|rx].state isn't ISOTP_IDLE yet, so a timer left running by a prior NETDEV_UNREGISTER can't act on a newly bound so->ifindex. Both checks share the same lock_sock() section, so there is no window in which a ",
    "evidence": "osv:CVE-2026-72125",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.265",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.216",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.183",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.148",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.101",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.40",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-72125",
      "aliases": [
        "CVE-2026-72125"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e057dd3fc20ffb3d7f150af46542a51b59b90127"
                },
                {
                  "fixed": "f311bbb29bb06aaab69ba45a6e4b11323d20b8f9"
                },
                {
                  "fixed": "8e018f4335590460ebcf0c2b493ed38ba1a35204"
                },
                {
                  "fixed": "33b9cd9245e2a4b800f99ed1cc53d64960614152"
                },
                {
                  "fixed": "0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96"
                },
                {
                  "fixed": "43884dc7963beef2328f507f4fe680bdc173eb80"
                },
                {
                  "fixed": "7bef39ba76eb7307ed22a50329e0f5776dbeda58"
                },
                {
                  "fixed": "e442b62ba5a7756c17e05a77b32cdd085a2b6138"
                },
                {
                  "fixed": "20bab8b88baac140ca3701116e1d486c7f51e311"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72125.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.10.0"
                },
                {
                  "fixed": "5.10.265"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.216"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.183"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.148"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.101"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.40"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72125.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.184115930Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0b811c4bbe3ec9ad611e90a540fe8b51b3bb8a96",
        "https://git.kernel.org/stable/c/20bab8b88baac140ca3701116e1d486c7f51e311",
        "https://git.kernel.org/stable/c/33b9cd9245e2a4b800f99ed1cc53d64960614152",
        "https://git.kernel.org/stable/c/43884dc7963beef2328f507f4fe680bdc173eb80",
        "https://git.kernel.org/stable/c/7bef39ba76eb7307ed22a50329e0f5776dbeda58",
        "https://git.kernel.org/stable/c/8e018f4335590460ebcf0c2b493ed38ba1a35204",
        "https://git.kernel.org/stable/c/e442b62ba5a7756c17e05a77b32cdd085a2b6138",
        "https://git.kernel.org/stable/c/f311bbb29bb06aaab69ba45a6e4b11323d20b8f9",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72125.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72125",
        "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/2026/72xxx/CVE-2026-72125.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-72125",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489732,
  "published_at": "2026-08-15T05:53:02.905+00:00"
}