{
  "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-2025-39874",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-39874",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-09-23T06:00:46.690Z",
    "updatedAt": "2026-05-11T21:38:05.960Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "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": "macsec: sync features on RTM_NEWLINK",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: sync features on RTM_NEWLINK\n\nSyzkaller managed to lock the lower device via ETHTOOL_SFEATURES:\n\n netdev_lock include/linux/netdevice.h:2761 [inline]\n netdev_lock_ops include/net/netdev_lock.h:42 [inline]\n netdev_sync_lower_features net/core/dev.c:10649 [inline]\n __netdev_update_features+0xcb1/0x1be0 net/core/dev.c:10819\n netdev_update_features+0x6d/0xe0 net/core/dev.c:10876\n macsec_notify+0x2f5/0x660 drivers/net/macsec.c:4533\n notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85\n call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]\n call_netdevice_notifiers net/core/dev.c:2281 [inline]\n netdev_features_change+0x85/0xc0 net/core/dev.c:1570\n __dev_ethtool net/ethtool/ioctl.c:3469 [inline]\n dev_ethtool+0x1536/0x19b0 net/ethtool/ioctl.c:3502\n dev_ioctl+0x392/0x1150 net/core/dev_ioctl.c:759\n\nIt happens because lower features are out of sync with the upper:\n\n  __dev_ethtool (real_dev)\n    netdev_lock_ops(real_dev)\n    ETHTOOL_SFEATURES\n      __netdev_features_change\n        netdev_sync_upper_features\n          disable LRO on the lower\n    if (old_features != dev->features)\n      netdev_features_change\n        fires NETDEV_FEAT_CHANGE\n\tmacsec_notify\n\t  NETDEV_FEAT_CHANGE\n\t    netdev_update_features (for each macsec dev)\n\t      netdev_sync_lower_features\n\t        if (upper_features != lower_features)\n\t          netdev_lock_ops(lower) # lower == real_dev\n\t\t  stuck\n\t\t  ...\n\n    netdev_unlock_ops(real_dev)\n\nPer commit af5f54b0ef9e (\"net: Lock lower level devices when updating\nfeatures\"), we elide the lock/unlock when the upper and lower features\nare synced. Makes sure the lower (real_dev) has proper features after\nthe macsec link has been created. This makes sure we never hit the\nsituation where we need to sync upper flags to the lower.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "7e4d784f5810bba76c4593791028e13cce4af547",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d7624629ccf47135c65fef0701fa0d9a115b87f3"
            },
            {
              "version": "7e4d784f5810bba76c4593791028e13cce4af547",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0f82c3ba66c6b2e3cde0f255156a753b108ee9dc"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.15",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.15"
            },
            {
              "version": "6.16.8",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.16.*"
            },
            {
              "version": "6.17",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}