{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b"
            },
            {
              "fixed": "69b78b5f3033272e53a2dc2dad675962654a5b38"
            },
            {
              "fixed": "41e8478c4cd896d3abbe33d41afc90c84ac66602"
            },
            {
              "fixed": "f4d78a81f57df82e9d82a2c07471fed1a1235893"
            },
            {
              "fixed": "02f1c87ded33b43d48b4a1d665da15f2157b30d8"
            },
            {
              "fixed": "9ea8a648d9120f7652bcde1ce2c4ad66871af707"
            },
            {
              "fixed": "563090e5d450c665f70d955a39f9587afc7842eb"
            },
            {
              "fixed": "8ba68464e4787b6a7ec938826e16124df20fd23d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.25"
            },
            {
              "fixed": "5.15.210"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.176"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.143"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.93"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.35"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63990.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbonding: refuse to enslave CAN devices\n\nsyzbot reported a kernel paging request crash in\ncan_rx_unregister() inside net/can/af_can.c. The crash occurs\nbecause a virtual CAN device (vxcan) is being enslaved to a\nbonding master.\n\nDuring the enslavement process, the bonding driver mutates\nand modifies the network device states to fit an Ethernet-like\naggregation model. However, CAN devices operate on a completely\ndifferent Layer 2 architecture, relying on the CAN mid-layer\nprivate data structure (can_ml_priv) instead of standard\nEthernet structures. Since bonding does not initialize or\nmaintain these CAN structures, subsequent operations on the\nhalf-enslaved interface (such as closing associated sockets\nvia isotp_release) lead to a null-pointer dereference when\naccessing the CAN receiver lists.\n\nBonding CAN interfaces is architecturally invalid as CAN lacks\nMAC addresses, ARP capabilities, and standard Ethernet\nlink-layer mechanisms. While generic loopback devices are\nblocked globally in net/core/dev.c, virtual CAN devices\nbypass this check because they do not carry the IFF_LOOPBACK\nflag, despite acting as local software-loopbacks.\n\nFix this by explicitly blocking network devices of type\nARPHRD_CAN from being enslaved at the very beginning of\nbond_enslave(). This prevents illegal state mutations,\neliminates the resulting KASAN crashes, and avoids potential\nmemory leaks from incomplete socket cleanups.\n\nAs the CAN support has been added a long time after bonding\nthe Fixes-tag points to the introduction of ARPHRD_CAN that\nwould have needed a specific handling in bonding_main.c.",
  "id": "CVE-2026-63990",
  "modified": "2026-08-12T03:51:48.177800267Z",
  "published": "2026-07-19T14:56:11.111Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/02f1c87ded33b43d48b4a1d665da15f2157b30d8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/41e8478c4cd896d3abbe33d41afc90c84ac66602"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/563090e5d450c665f70d955a39f9587afc7842eb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/69b78b5f3033272e53a2dc2dad675962654a5b38"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8ba68464e4787b6a7ec938826e16124df20fd23d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9ea8a648d9120f7652bcde1ce2c4ad66871af707"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f4d78a81f57df82e9d82a2c07471fed1a1235893"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63990.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63990"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "bonding: refuse to enslave CAN devices"
}