{"api_version":"1","generated_at":"2026-07-23T13:24:22+00:00","cve":"CVE-2026-63990","urls":{"html":"https://cve.report/CVE-2026-63990","api":"https://cve.report/api/cve/CVE-2026-63990.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63990","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63990"},"summary":{"title":"bonding: refuse to enslave CAN devices","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 16:17:18","updated_at":"2026-07-19 16:17:18"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/41e8478c4cd896d3abbe33d41afc90c84ac66602","name":"https://git.kernel.org/stable/c/41e8478c4cd896d3abbe33d41afc90c84ac66602","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8ba68464e4787b6a7ec938826e16124df20fd23d","name":"https://git.kernel.org/stable/c/8ba68464e4787b6a7ec938826e16124df20fd23d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/02f1c87ded33b43d48b4a1d665da15f2157b30d8","name":"https://git.kernel.org/stable/c/02f1c87ded33b43d48b4a1d665da15f2157b30d8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/563090e5d450c665f70d955a39f9587afc7842eb","name":"https://git.kernel.org/stable/c/563090e5d450c665f70d955a39f9587afc7842eb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9ea8a648d9120f7652bcde1ce2c4ad66871af707","name":"https://git.kernel.org/stable/c/9ea8a648d9120f7652bcde1ce2c4ad66871af707","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f4d78a81f57df82e9d82a2c07471fed1a1235893","name":"https://git.kernel.org/stable/c/f4d78a81f57df82e9d82a2c07471fed1a1235893","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/69b78b5f3033272e53a2dc2dad675962654a5b38","name":"https://git.kernel.org/stable/c/69b78b5f3033272e53a2dc2dad675962654a5b38","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63990","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63990","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd05acfe65ed2cf2db683fa9a6adb8d35635263b 69b78b5f3033272e53a2dc2dad675962654a5b38 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd05acfe65ed2cf2db683fa9a6adb8d35635263b 41e8478c4cd896d3abbe33d41afc90c84ac66602 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd05acfe65ed2cf2db683fa9a6adb8d35635263b f4d78a81f57df82e9d82a2c07471fed1a1235893 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cd05acfe65ed2cf2db683fa9a6adb8d35635263b 02f1c87ded33b43d48b4a1d665da15f2157b30d8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.93 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.35 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.12 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63990","cve":"CVE-2026-63990","epss":"0.001810000","percentile":"0.078870000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"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"},"nvd":{"publishedDate":"2026-07-19 16:17:18","lastModifiedDate":"2026-07-19 16:17:18","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63990","Ordinal":"1","Title":"bonding: refuse to enslave CAN devices","CVE":"CVE-2026-63990","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63990","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"bonding: refuse to enslave CAN devices"}]}}}