CVE-2026-63990 (GCVE-0-2026-63990)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-07-19 14:56
VLAI
Title
bonding: refuse to enslave CAN devices
Summary
In the Linux kernel, the following vulnerability has been resolved: bonding: refuse to enslave CAN devices syzbot reported a kernel paging request crash in can_rx_unregister() inside net/can/af_can.c. The crash occurs because a virtual CAN device (vxcan) is being enslaved to a bonding master. During the enslavement process, the bonding driver mutates and modifies the network device states to fit an Ethernet-like aggregation model. However, CAN devices operate on a completely different Layer 2 architecture, relying on the CAN mid-layer private data structure (can_ml_priv) instead of standard Ethernet structures. Since bonding does not initialize or maintain these CAN structures, subsequent operations on the half-enslaved interface (such as closing associated sockets via isotp_release) lead to a null-pointer dereference when accessing the CAN receiver lists. Bonding CAN interfaces is architecturally invalid as CAN lacks MAC addresses, ARP capabilities, and standard Ethernet link-layer mechanisms. While generic loopback devices are blocked globally in net/core/dev.c, virtual CAN devices bypass this check because they do not carry the IFF_LOOPBACK flag, despite acting as local software-loopbacks. Fix this by explicitly blocking network devices of type ARPHRD_CAN from being enslaved at the very beginning of bond_enslave(). This prevents illegal state mutations, eliminates the resulting KASAN crashes, and avoids potential memory leaks from incomplete socket cleanups. As the CAN support has been added a long time after bonding the Fixes-tag points to the introduction of ARPHRD_CAN that would have needed a specific handling in bonding_main.c.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < 69b78b5f3033272e53a2dc2dad675962654a5b38 (git)
Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < 41e8478c4cd896d3abbe33d41afc90c84ac66602 (git)
Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < f4d78a81f57df82e9d82a2c07471fed1a1235893 (git)
Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < 02f1c87ded33b43d48b4a1d665da15f2157b30d8 (git)
Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < 9ea8a648d9120f7652bcde1ce2c4ad66871af707 (git)
Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < 563090e5d450c665f70d955a39f9587afc7842eb (git)
Affected: cd05acfe65ed2cf2db683fa9a6adb8d35635263b , < 8ba68464e4787b6a7ec938826e16124df20fd23d (git)
Create a notification for this product.
Linux Linux Affected: 2.6.25
Unaffected: 0 , < 2.6.25 (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 6.18.35 , ≤ 6.18.* (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/bonding/bond_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "69b78b5f3033272e53a2dc2dad675962654a5b38",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            },
            {
              "lessThan": "41e8478c4cd896d3abbe33d41afc90c84ac66602",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            },
            {
              "lessThan": "f4d78a81f57df82e9d82a2c07471fed1a1235893",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            },
            {
              "lessThan": "02f1c87ded33b43d48b4a1d665da15f2157b30d8",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            },
            {
              "lessThan": "9ea8a648d9120f7652bcde1ce2c4ad66871af707",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            },
            {
              "lessThan": "563090e5d450c665f70d955a39f9587afc7842eb",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            },
            {
              "lessThan": "8ba68464e4787b6a7ec938826e16124df20fd23d",
              "status": "affected",
              "version": "cd05acfe65ed2cf2db683fa9a6adb8d35635263b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/bonding/bond_main.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.25"
            },
            {
              "lessThan": "2.6.25",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.210",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.176",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.143",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.93",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.35",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.12",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "2.6.25",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-19T14:56:11.111Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/69b78b5f3033272e53a2dc2dad675962654a5b38"
        },
        {
          "url": "https://git.kernel.org/stable/c/41e8478c4cd896d3abbe33d41afc90c84ac66602"
        },
        {
          "url": "https://git.kernel.org/stable/c/f4d78a81f57df82e9d82a2c07471fed1a1235893"
        },
        {
          "url": "https://git.kernel.org/stable/c/02f1c87ded33b43d48b4a1d665da15f2157b30d8"
        },
        {
          "url": "https://git.kernel.org/stable/c/9ea8a648d9120f7652bcde1ce2c4ad66871af707"
        },
        {
          "url": "https://git.kernel.org/stable/c/563090e5d450c665f70d955a39f9587afc7842eb"
        },
        {
          "url": "https://git.kernel.org/stable/c/8ba68464e4787b6a7ec938826e16124df20fd23d"
        }
      ],
      "title": "bonding: refuse to enslave CAN devices",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63990",
    "datePublished": "2026-07-19T14:56:11.111Z",
    "dateReserved": "2026-07-19T07:54:57.025Z",
    "dateUpdated": "2026-07-19T14:56:11.111Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-63990",
      "date": "2026-07-21",
      "epss": "0.00181",
      "percentile": "0.07885"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-63990\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-19T16:17:18.610\",\"lastModified\":\"2026-07-19T16:17:18.610\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/net/bonding/bond_main.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"69b78b5f3033272e53a2dc2dad675962654a5b38\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"41e8478c4cd896d3abbe33d41afc90c84ac66602\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"f4d78a81f57df82e9d82a2c07471fed1a1235893\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"02f1c87ded33b43d48b4a1d665da15f2157b30d8\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"9ea8a648d9120f7652bcde1ce2c4ad66871af707\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"563090e5d450c665f70d955a39f9587afc7842eb\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"cd05acfe65ed2cf2db683fa9a6adb8d35635263b\",\"lessThan\":\"8ba68464e4787b6a7ec938826e16124df20fd23d\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/net/bonding/bond_main.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.25\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.25\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.210\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.176\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.143\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.93\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.35\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.12\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/02f1c87ded33b43d48b4a1d665da15f2157b30d8\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/41e8478c4cd896d3abbe33d41afc90c84ac66602\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/563090e5d450c665f70d955a39f9587afc7842eb\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/69b78b5f3033272e53a2dc2dad675962654a5b38\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/8ba68464e4787b6a7ec938826e16124df20fd23d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9ea8a648d9120f7652bcde1ce2c4ad66871af707\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f4d78a81f57df82e9d82a2c07471fed1a1235893\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}



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.