CVE-2025-39874

{"id": "CVE-2025-39874", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-39874", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-01-14T19:24:28.955571Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}, {"type": "Secondary", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "7e4d784f5810bba76c4593791028e13cce4af547", "lessThan": "d7624629ccf47135c65fef0701fa0d9a115b87f3", "versionType": "git"}, {"status": "affected", "version": "7e4d784f5810bba76c4593791028e13cce4af547", "lessThan": "0f82c3ba66c6b2e3cde0f255156a753b108ee9dc", "versionType": "git"}], "programFiles": ["drivers/net/macsec.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"status": "unaffected", "version": "0", "lessThan": "6.15", "versionType": "semver"}, {"status": "unaffected", "version": "6.16.8", "versionType": "semver", "lessThanOrEqual": "6.16.*"}, {"status": "unaffected", "version": "6.17", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/net/macsec.c"], "defaultStatus": "affected"}]}], "published": "2025-09-23T06:15:46.813", "references": [{"url": "https://git.kernel.org/stable/c/0f82c3ba66c6b2e3cde0f255156a753b108ee9dc", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/d7624629ccf47135c65fef0701fa0d9a115b87f3", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nmacsec: sincronizar caracter\u00edsticas en RTM_NEWLINK\n\nSyzkaller logr\u00f3 bloquear el dispositivo inferior a trav\u00e9s de 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\nSucede porque las caracter\u00edsticas inferiores est\u00e1n desincronizadas con las superiores:\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 deshabilitar LRO en el inferior\n if (old_features != dev->features)\n netdev_features_change\n dispara NETDEV_FEAT_CHANGE\n\tmacsec_notify\n\t NETDEV_FEAT_CHANGE\n\t netdev_update_features (para cada dispositivo macsec)\n\t netdev_sync_lower_features\n\t if (upper_features != lower_features)\n\t netdev_lock_ops(lower) # inferior == real_dev\n\t\t atascado\n\t\t ...\n\n netdev_unlock_ops(real_dev)\n\nSeg\u00fan el commit af5f54b0ef9e ('net: Bloquear dispositivos de nivel inferior al actualizar caracter\u00edsticas'), omitimos el bloqueo/desbloqueo cuando las caracter\u00edsticas superiores e inferiores est\u00e1n sincronizadas. Asegura que el inferior (real_dev) tenga las caracter\u00edsticas adecuadas despu\u00e9s de que se haya creado el enlace macsec. Esto asegura que nunca lleguemos a la situaci\u00f3n en la que necesitemos sincronizar las banderas superiores con las inferiores."}], "lastModified": "2026-10-19T21:10:00.160", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4CDBA6F5-ADD5-4E49-89EE-9FA2364F2685", "versionEndExcluding": "6.16.8", "versionStartIncluding": "6.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C730CD9A-D969-4A8E-9522-162AAF7C0EE9"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "39982C4B-716E-4B2F-8196-FA301F47807D"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "340BEEA9-D70D-4290-B502-FBB1032353B1"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "47E4C5C0-079F-4838-971B-8C503D48FCC2"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}