GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2021-47459 (GCVE-0-2021-47459)

Vulnerability from cvelistv5 – Published: 2024-05-22 06:23 – Updated: 2026-08-05 08:47
VLAI
Title
can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv
Summary
In the Linux kernel, the following vulnerability has been resolved: can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv It will trigger UAF for rx_kref of j1939_priv as following. cpu0 cpu1 j1939_sk_bind(socket0, ndev0, ...) j1939_netdev_start j1939_sk_bind(socket1, ndev0, ...) j1939_netdev_start j1939_priv_set j1939_priv_get_by_ndev_locked j1939_jsk_add ..... j1939_netdev_stop kref_put_lock(&priv->rx_kref, ...) kref_get(&priv->rx_kref, ...) REFCOUNT_WARN("addition on 0;...") ==================================================== refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 Call Trace: j1939_netdev_start+0x68b/0x920 j1939_sk_bind+0x426/0xeb0 ? security_socket_bind+0x83/0xb0 The rx_kref's kref_get() and kref_put() should use j1939_netdev_lock to protect.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-09-10 15:36 UTC
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 9d71dd0c70099914fcd063135da3c580865e924c , < a0e47d2833b4f65e6c799f28c6b636d36b8b936d (git)
Affected: 9d71dd0c70099914fcd063135da3c580865e924c , < 864e77771a24c877aaf53aee019f78619cbcd668 (git)
Affected: 9d71dd0c70099914fcd063135da3c580865e924c , < 6e8811707e2df0c6ba920f0cad3a3bca7b42132f (git)
Affected: 9d71dd0c70099914fcd063135da3c580865e924c , < d9d52a3ebd284882f5562c88e55991add5d01586 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.4
Unaffected: 0 , < 5.4 (semver)
Unaffected: 5.4.156 , ≤ 5.4.* (semver)
Unaffected: 5.10.76 , ≤ 5.10.* (semver)
Unaffected: 5.14.15 , ≤ 5.14.* (semver)
Unaffected: 5.15 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T05:39:59.451Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-47459",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-09-10T15:36:14.848678Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-09-11T17:33:25.941Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/can/j1939/main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a0e47d2833b4f65e6c799f28c6b636d36b8b936d",
              "status": "affected",
              "version": "9d71dd0c70099914fcd063135da3c580865e924c",
              "versionType": "git"
            },
            {
              "lessThan": "864e77771a24c877aaf53aee019f78619cbcd668",
              "status": "affected",
              "version": "9d71dd0c70099914fcd063135da3c580865e924c",
              "versionType": "git"
            },
            {
              "lessThan": "6e8811707e2df0c6ba920f0cad3a3bca7b42132f",
              "status": "affected",
              "version": "9d71dd0c70099914fcd063135da3c580865e924c",
              "versionType": "git"
            },
            {
              "lessThan": "d9d52a3ebd284882f5562c88e55991add5d01586",
              "status": "affected",
              "version": "9d71dd0c70099914fcd063135da3c580865e924c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/can/j1939/main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.4"
            },
            {
              "lessThan": "5.4",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.156",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.76",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.14.*",
              "status": "unaffected",
              "version": "5.14.15",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.15",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.156",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.76",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.14.15",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15",
                  "versionStartIncluding": "5.4",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv\n\nIt will trigger UAF for rx_kref of j1939_priv as following.\n\n        cpu0                                    cpu1\nj1939_sk_bind(socket0, ndev0, ...)\nj1939_netdev_start\n                                        j1939_sk_bind(socket1, ndev0, ...)\n                                        j1939_netdev_start\nj1939_priv_set\n                                        j1939_priv_get_by_ndev_locked\nj1939_jsk_add\n.....\nj1939_netdev_stop\nkref_put_lock(\u0026priv-\u003erx_kref, ...)\n                                        kref_get(\u0026priv-\u003erx_kref, ...)\n                                        REFCOUNT_WARN(\"addition on 0;...\")\n\n====================================================\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0\nRIP: 0010:refcount_warn_saturate+0x169/0x1e0\nCall Trace:\n j1939_netdev_start+0x68b/0x920\n j1939_sk_bind+0x426/0xeb0\n ? security_socket_bind+0x83/0xb0\n\nThe rx_kref\u0027s kref_get() and kref_put() should use j1939_netdev_lock to\nprotect."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The bug is reached only through local syscalls (socket/bind/close) into j1939_sk_bind \u2192 j1939_netdev_start/stop; it is not triggered by receiving CAN/J1939 frames from the wire.\nAC:L - The race is fully attacker-controlled by opening multiple J1939 sockets and concurrently binding/closing them on the same CAN interface, as demonstrated by the syzbot threaded reproducers.\nPR:L - Creating and binding CAN_J1939 sockets requires no capabilities; an unprivileged user can reach the path on an existing UP CAN device or by creating vcan in a user/net namespace with namespaced CAP_NET_ADMIN.\nUI:N - Exploitation requires no victim action beyond the attacker\u2019s own socket operations.\nS:U - This is a standard in-kernel memory-safety flaw affecting the host kernel authority, with no VM/IOMMU/sandbox boundary crossing.\nC:H - The vulnerability is a use-after-free on j1939_priv refcounting; UAF enables reclaim/spray of the freed object and arbitrary kernel memory disclosure.\nI:H - Use-after-free of j1939_priv state enables heap manipulation and write primitives sufficient for control-flow hijacking or arbitrary kernel writes.\nA:H - The UAF reliably produces refcount warnings and kernel oops/crash conditions even without full exploitation, denying availability."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:47:56.231Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
        },
        {
          "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
        },
        {
          "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
        },
        {
          "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
        }
      ],
      "title": "can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2021-47459",
    "datePublished": "2024-05-22T06:23:21.061Z",
    "dateReserved": "2024-05-22T06:20:56.197Z",
    "dateUpdated": "2026-08-05T08:47:56.231Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-47459",
      "date": "2026-09-19",
      "epss": "0.00225",
      "percentile": "0.13396"
    },
    "fkie_nvd": {
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv\n\nIt will trigger UAF for rx_kref of j1939_priv as following.\n\n        cpu0                                    cpu1\nj1939_sk_bind(socket0, ndev0, ...)\nj1939_netdev_start\n                                        j1939_sk_bind(socket1, ndev0, ...)\n                                        j1939_netdev_start\nj1939_priv_set\n                                        j1939_priv_get_by_ndev_locked\nj1939_jsk_add\n.....\nj1939_netdev_stop\nkref_put_lock(\u0026priv-\u003erx_kref, ...)\n                                        kref_get(\u0026priv-\u003erx_kref, ...)\n                                        REFCOUNT_WARN(\"addition on 0;...\")\n\n====================================================\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0\nRIP: 0010:refcount_warn_saturate+0x169/0x1e0\nCall Trace:\n j1939_netdev_start+0x68b/0x920\n j1939_sk_bind+0x426/0xeb0\n ? security_socket_bind+0x83/0xb0\n\nThe rx_kref\u0027s kref_get() and kref_put() should use j1939_netdev_lock to\nprotect."
        },
        {
          "lang": "es",
          "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: can: j1939: j1939_netdev_start(): arreglar UAF para rx_kref de j1939_priv Activar\u00e1 UAF para rx_kref de j1939_priv de la siguiente manera. cpu0 cpu1 j1939_sk_bind(socket0, ndev0, ...) j1939_netdev_start j1939_sk_bind(socket1, ndev0, ...) j1939_netdev_start j1939_priv_set j1939_priv_get_by_ndev_locked j1939_jsk_add ..... kref_put_lock(\u0026amp;priv-\u0026gt;rx_kref, ...) kref_get(\u0026amp;priv-\u0026gt;rx_kref , ...) REFCOUNT_WARN(\"adici\u00f3n en 0;...\") ================================== ==================== refcount_t: suma en 0; use-after-free. ADVERTENCIA: CPU: 1 PID: 20874 en lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 Seguimiento de llamadas: j1939_netdev_start+0x68b/0x920 j1939_sk_bind+0x426 /0xeb0 ? security_socket_bind+0x83/0xb0 Los kref_get() y kref_put() de rx_kref deben usar j1939_netdev_lock para proteger."
        }
      ],
      "id": "CVE-2021-47459",
      "lastModified": "2024-11-21T06:36:11.650",
      "published": "2024-05-22T07:15:10.863",
      "references": [
        {
          "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
        },
        {
          "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
        },
        {
          "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
        },
        {
          "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
          "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
        }
      ],
      "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "vulnStatus": "Undergoing Analysis"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "net/can/j1939/main.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "a0e47d2833b4f65e6c799f28c6b636d36b8b936d",
                    "status": "affected",
                    "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "864e77771a24c877aaf53aee019f78619cbcd668",
                    "status": "affected",
                    "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "6e8811707e2df0c6ba920f0cad3a3bca7b42132f",
                    "status": "affected",
                    "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "d9d52a3ebd284882f5562c88e55991add5d01586",
                    "status": "affected",
                    "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "net/can/j1939/main.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "5.4"
                  },
                  {
                    "lessThan": "5.4",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.4.*",
                    "status": "unaffected",
                    "version": "5.4.156",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.10.*",
                    "status": "unaffected",
                    "version": "5.10.76",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "5.14.*",
                    "status": "unaffected",
                    "version": "5.14.15",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "5.15",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "5D0CFAC2-0100-453F-A6D1-EBEA710C7383",
                    "versionEndExcluding": "5.4.156",
                    "versionStartIncluding": "5.4",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "E61528CE-9083-425B-AE36-3791232BF780",
                    "versionEndExcluding": "5.10.76",
                    "versionStartIncluding": "5.5",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "63BD46C4-473F-45F9-93E9-F67D955321D8",
                    "versionEndExcluding": "5.14.15",
                    "versionStartIncluding": "5.11",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*",
                    "matchCriteriaId": "E46C74C6-B76B-4C94-A6A4-FD2FFF62D644",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*",
                    "matchCriteriaId": "60134C3A-06E4-48C1-B04F-2903732A4E56",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*",
                    "matchCriteriaId": "0460DA88-8FE1-46A2-9DDA-1F1ABA552E71",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*",
                    "matchCriteriaId": "AF55383D-4DF2-45DC-93F7-571F4F978EAB",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*",
                    "matchCriteriaId": "9E9481B2-8AA6-4CBD-B5D3-C10F51FF6D01",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*",
                    "matchCriteriaId": "EBD45831-4B79-42BC-ABC0-86870F0DEA89",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv\n\nIt will trigger UAF for rx_kref of j1939_priv as following.\n\n        cpu0                                    cpu1\nj1939_sk_bind(socket0, ndev0, ...)\nj1939_netdev_start\n                                        j1939_sk_bind(socket1, ndev0, ...)\n                                        j1939_netdev_start\nj1939_priv_set\n                                        j1939_priv_get_by_ndev_locked\nj1939_jsk_add\n.....\nj1939_netdev_stop\nkref_put_lock(\u0026priv-\u003erx_kref, ...)\n                                        kref_get(\u0026priv-\u003erx_kref, ...)\n                                        REFCOUNT_WARN(\"addition on 0;...\")\n\n====================================================\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0\nRIP: 0010:refcount_warn_saturate+0x169/0x1e0\nCall Trace:\n j1939_netdev_start+0x68b/0x920\n j1939_sk_bind+0x426/0xeb0\n ? security_socket_bind+0x83/0xb0\n\nThe rx_kref\u0027s kref_get() and kref_put() should use j1939_netdev_lock to\nprotect."
          },
          {
            "lang": "es",
            "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: can: j1939: j1939_netdev_start(): arreglar UAF para rx_kref de j1939_priv Activar\u00e1 UAF para rx_kref de j1939_priv de la siguiente manera. cpu0 cpu1 j1939_sk_bind(socket0, ndev0, ...) j1939_netdev_start j1939_sk_bind(socket1, ndev0, ...) j1939_netdev_start j1939_priv_set j1939_priv_get_by_ndev_locked j1939_jsk_add ..... kref_put_lock(\u0026amp;priv-\u0026gt;rx_kref, ...) kref_get(\u0026amp;priv-\u0026gt;rx_kref , ...) REFCOUNT_WARN(\"adici\u00f3n en 0;...\") ================================== ==================== refcount_t: suma en 0; use-after-free. ADVERTENCIA: CPU: 1 PID: 20874 en lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 Seguimiento de llamadas: j1939_netdev_start+0x68b/0x920 j1939_sk_bind+0x426 /0xeb0 ? security_socket_bind+0x83/0xb0 Los kref_get() y kref_put() de rx_kref deben usar j1939_netdev_lock para proteger."
          }
        ],
        "id": "CVE-2021-47459",
        "lastModified": "2026-08-04T10:17:04.430",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            },
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ],
          "ssvcV203": [
            {
              "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "ssvcData": {
                "id": "CVE-2021-47459",
                "options": [
                  {
                    "exploitation": "none"
                  },
                  {
                    "automatable": "no"
                  },
                  {
                    "technicalImpact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-09-10T15:36:14.848678Z",
                "version": "2.0.3"
              }
            }
          ]
        },
        "published": "2024-05-22T07:15:10.863",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch"
            ],
            "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-416"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-04T19:56:29+00:00",
      "cve": "CVE-2021-47459",
      "id": "CVE-2021-47459",
      "initial_release_date": "2021-01-01T00:00:00+00:00",
      "product_status:fixed": "513",
      "product_status:known_affected": "22",
      "product_status:known_not_affected": "91",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-47459.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-11T02:37:58Z",
      "cve": "CVE-2021-47459",
      "id": "CVE-2021-47459",
      "initial_release_date": "2024-05-25T03:33:58Z",
      "product_status:known_affected": "275",
      "product_status:known_not_affected": "266",
      "product_status:recommended": "481",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2021-47459",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2021-47459.json",
      "version": "56"
    },
    "vulnrichment": {
      "containers": {
        "adp": [
          {
            "providerMetadata": {
              "dateUpdated": "2024-08-04T05:39:59.451Z",
              "orgId": "af854a3a-2127-422b-91ae-364da2661108",
              "shortName": "CVE"
            },
            "references": [
              {
                "tags": [
                  "x_transferred"
                ],
                "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
              },
              {
                "tags": [
                  "x_transferred"
                ],
                "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
              },
              {
                "tags": [
                  "x_transferred"
                ],
                "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
              },
              {
                "tags": [
                  "x_transferred"
                ],
                "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
              }
            ],
            "title": "CVE Program Container"
          },
          {
            "metrics": [
              {
                "other": {
                  "content": {
                    "id": "CVE-2021-47459",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "role": "CISA Coordinator",
                    "timestamp": "2024-09-10T15:36:14.848678Z",
                    "version": "2.0.3"
                  },
                  "type": "ssvc"
                }
              }
            ],
            "providerMetadata": {
              "dateUpdated": "2024-09-11T12:42:16.653Z",
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
          }
        ],
        "cna": {
          "affected": [
            {
              "defaultStatus": "unaffected",
              "product": "Linux",
              "programFiles": [
                "net/can/j1939/main.c"
              ],
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
                {
                  "lessThan": "a0e47d2833b4f65e6c799f28c6b636d36b8b936d",
                  "status": "affected",
                  "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                  "versionType": "git"
                },
                {
                  "lessThan": "864e77771a24c877aaf53aee019f78619cbcd668",
                  "status": "affected",
                  "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                  "versionType": "git"
                },
                {
                  "lessThan": "6e8811707e2df0c6ba920f0cad3a3bca7b42132f",
                  "status": "affected",
                  "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                  "versionType": "git"
                },
                {
                  "lessThan": "d9d52a3ebd284882f5562c88e55991add5d01586",
                  "status": "affected",
                  "version": "9d71dd0c70099914fcd063135da3c580865e924c",
                  "versionType": "git"
                }
              ]
            },
            {
              "defaultStatus": "affected",
              "product": "Linux",
              "programFiles": [
                "net/can/j1939/main.c"
              ],
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "vendor": "Linux",
              "versions": [
                {
                  "status": "affected",
                  "version": "5.4"
                },
                {
                  "lessThan": "5.4",
                  "status": "unaffected",
                  "version": "0",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.4.*",
                  "status": "unaffected",
                  "version": "5.4.156",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.10.*",
                  "status": "unaffected",
                  "version": "5.10.76",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "5.14.*",
                  "status": "unaffected",
                  "version": "5.14.15",
                  "versionType": "semver"
                },
                {
                  "lessThanOrEqual": "*",
                  "status": "unaffected",
                  "version": "5.15",
                  "versionType": "original_commit_for_fix"
                }
              ]
            }
          ],
          "cpeApplicability": [
            {
              "nodes": [
                {
                  "cpeMatch": [
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.4.156",
                      "versionStartIncluding": "5.4",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.10.76",
                      "versionStartIncluding": "5.4",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.14.15",
                      "versionStartIncluding": "5.4",
                      "vulnerable": true
                    },
                    {
                      "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                      "versionEndExcluding": "5.15",
                      "versionStartIncluding": "5.4",
                      "vulnerable": true
                    }
                  ],
                  "negate": false,
                  "operator": "OR"
                }
              ]
            }
          ],
          "descriptions": [
            {
              "lang": "en",
              "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv\n\nIt will trigger UAF for rx_kref of j1939_priv as following.\n\n        cpu0                                    cpu1\nj1939_sk_bind(socket0, ndev0, ...)\nj1939_netdev_start\n                                        j1939_sk_bind(socket1, ndev0, ...)\n                                        j1939_netdev_start\nj1939_priv_set\n                                        j1939_priv_get_by_ndev_locked\nj1939_jsk_add\n.....\nj1939_netdev_stop\nkref_put_lock(\u0026priv-\u003erx_kref, ...)\n                                        kref_get(\u0026priv-\u003erx_kref, ...)\n                                        REFCOUNT_WARN(\"addition on 0;...\")\n\n====================================================\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0\nRIP: 0010:refcount_warn_saturate+0x169/0x1e0\nCall Trace:\n j1939_netdev_start+0x68b/0x920\n j1939_sk_bind+0x426/0xeb0\n ? security_socket_bind+0x83/0xb0\n\nThe rx_kref\u0027s kref_get() and kref_put() should use j1939_netdev_lock to\nprotect."
            }
          ],
          "metrics": [
            {
              "cvssV3_1": {
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "scenarios": [
                {
                  "lang": "en",
                  "value": "AV:L - The bug is reached only through local syscalls (socket/bind/close) into j1939_sk_bind \u2192 j1939_netdev_start/stop; it is not triggered by receiving CAN/J1939 frames from the wire.\nAC:L - The race is fully attacker-controlled by opening multiple J1939 sockets and concurrently binding/closing them on the same CAN interface, as demonstrated by the syzbot threaded reproducers.\nPR:L - Creating and binding CAN_J1939 sockets requires no capabilities; an unprivileged user can reach the path on an existing UP CAN device or by creating vcan in a user/net namespace with namespaced CAP_NET_ADMIN.\nUI:N - Exploitation requires no victim action beyond the attacker\u2019s own socket operations.\nS:U - This is a standard in-kernel memory-safety flaw affecting the host kernel authority, with no VM/IOMMU/sandbox boundary crossing.\nC:H - The vulnerability is a use-after-free on j1939_priv refcounting; UAF enables reclaim/spray of the freed object and arbitrary kernel memory disclosure.\nI:H - Use-after-free of j1939_priv state enables heap manipulation and write primitives sufficient for control-flow hijacking or arbitrary kernel writes.\nA:H - The UAF reliably produces refcount warnings and kernel oops/crash conditions even without full exploitation, denying availability."
                }
              ]
            }
          ],
          "providerMetadata": {
            "dateUpdated": "2026-08-05T08:47:56.231Z",
            "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "shortName": "Linux"
          },
          "references": [
            {
              "url": "https://git.kernel.org/stable/c/a0e47d2833b4f65e6c799f28c6b636d36b8b936d"
            },
            {
              "url": "https://git.kernel.org/stable/c/864e77771a24c877aaf53aee019f78619cbcd668"
            },
            {
              "url": "https://git.kernel.org/stable/c/6e8811707e2df0c6ba920f0cad3a3bca7b42132f"
            },
            {
              "url": "https://git.kernel.org/stable/c/d9d52a3ebd284882f5562c88e55991add5d01586"
            }
          ],
          "title": "can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv",
          "x_generator": {
            "engine": "bippy-1.2.0"
          }
        }
      },
      "cveMetadata": {
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "assignerShortName": "Linux",
        "cveId": "CVE-2021-47459",
        "datePublished": "2024-05-22T06:23:21.061Z",
        "dateReserved": "2024-05-22T06:20:56.197Z",
        "dateUpdated": "2026-08-05T08:47:56.231Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.