{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-23209", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-23209", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-02-14T16:27:31.175Z", "updatedAt": "2026-10-19T18:35:38.702Z", "importedAt": "2026-10-24T01:58:02.025Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "macvlan: fix error recovery in macvlan_common_newlink()", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmacvlan: fix error recovery in macvlan_common_newlink()\n\nvalis provided a nice repro to crash the kernel:\n\nip link add p1 type veth peer p2\nip link set address 00:00:00:00:00:20 dev p1\nip link set up dev p1\nip link set up dev p2\n\nip link add mv0 link p2 type macvlan mode source\nip link add invalid% link p2 type macvlan mode source macaddr add 00:00:00:00:00:20\n\nping -c1 -I p1 1.2.3.4\n\nHe also gave a very detailed analysis:\n\n\n\nThe issue is triggered when a new macvlan link is created with\nMACVLAN_MODE_SOURCE mode and MACVLAN_MACADDR_ADD (or\nMACVLAN_MACADDR_SET) parameter, lower device already has a macvlan\nport and register_netdevice() called from macvlan_common_newlink()\nfails (e.g. because of the invalid link name).\n\nIn this case macvlan_hash_add_source is called from\nmacvlan_change_sources() / macvlan_common_newlink():\n\nThis adds a reference to vlan to the port's vlan_source_hash using\nmacvlan_source_entry.\n\nvlan is a pointer to the priv data of the link that is being created.\n\nWhen register_netdevice() fails, the error is returned from\nmacvlan_newlink() to rtnl_newlink_create():\n\n if (ops->newlink)\n err = ops->newlink(dev, ¶ms, extack);\n else\n err = register_netdevice(dev);\n if (err < 0) {\n free_netdev(dev);\n goto out;\n }\n\nand free_netdev() is called, causing a kvfree() on the struct\nnet_device that is still referenced in the source entry attached to\nthe lower device's macvlan port.\n\nNow all packets sent on the macvlan port with a matching source mac\naddress will trigger a use-after-free in macvlan_forward_source().\n\n\n\nWith all that, my fix is to make sure we call macvlan_flush_sources()\nregardless of @create value whenever \"goto destroy_macvlan_port;\"\npath is taken.\n\nMany thanks to valis for following up on this issue.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "da5c6b8ae47e414be47e5e04def15b25d5c962dc" }, { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "5dae6b36a7cb7a4fcf4121b95e9ca7f96f816c8a" }, { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "c43d0e787cbba569ec9d11579ed370b50fab6c9c" }, { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "11ba9f0dc865136174cb98834280fb21bbc950c7" }, { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "986967a162142710076782d5b93daab93a892980" }, { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "cdedcd5aa3f3cb8b7ae0f87ab3a936d0bd583d66" }, { "version": "aa5fd0fb77486b8a6764ead8627baa14790e4280", "status": "affected", "versionType": "git", "lessThan": "f8db6475a83649689c087a8f52486fcc53e627e9" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "4.9" }, { "version": "5.10.250", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.200", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.163", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.124", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.70", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.10", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "6.19", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }