CVE-2026-43421

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43421", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.008Z", "datePublished": "2026-05-08T14:21:56.363Z", "dateUpdated": "2026-10-15T01:19:23.793Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-06-19T11:58:36.714Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: Fix net_device lifecycle with device_move\n\nThe network device outlived its parent gadget device during\ndisconnection, resulting in dangling sysfs links and null pointer\ndereference problems.\n\nA prior attempt to solve this by removing SET_NETDEV_DEV entirely [1]\nwas reverted due to power management ordering concerns and a NO-CARRIER\nregression.\n\nA subsequent attempt to defer net_device allocation to bind [2] broke\n1:1 mapping between function instance and network device, making it\nimpossible for configfs to report the resolved interface name. This\nresults in a regression where the DHCP server fails on pmOS.\n\nUse device_move to reparent the net_device between the gadget device and\n/sys/devices/virtual/ across bind/unbind cycles. This preserves the\nnetwork interface across USB reconnection, allowing the DHCP server to\nretain their binding.\n\nIntroduce gether_attach_gadget()/gether_detach_gadget() helpers and use\n__free(detach_gadget) macro to undo attachment on bind failure. The\nbind_count ensures device_move executes only on the first bind.\n\n[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/\n[2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/usb/gadget/function/f_ncm.c", "drivers/usb/gadget/function/u_ether.c", "drivers/usb/gadget/function/u_ether.h", "drivers/usb/gadget/function/u_ncm.h"], "versions": [{"version": "40d133d7f542616cf9538508a372306e626a16e9", "lessThan": "7c97366f5dac5255e60a317ffe3a5b18f3745547", "status": "affected", "versionType": "git"}, {"version": "40d133d7f542616cf9538508a372306e626a16e9", "lessThan": "36c41e9724c9a7a7cda37f5a4e9d94f25c8031c4", "status": "affected", "versionType": "git"}, {"version": "40d133d7f542616cf9538508a372306e626a16e9", "lessThan": "93f116c3393a22acab96ad1bef12b2572eb80ca4", "status": "affected", "versionType": "git"}, {"version": "40d133d7f542616cf9538508a372306e626a16e9", "lessThan": "e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d", "status": "affected", "versionType": "git"}, {"version": "40d133d7f542616cf9538508a372306e626a16e9", "lessThan": "85acaba2f42b557499bab3608307f17bf13beb69", "status": "affected", "versionType": "git"}, {"version": "40d133d7f542616cf9538508a372306e626a16e9", "lessThan": "ec35c1969650e7cb6c8a91020e568ed46e3551b0", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/usb/gadget/function/f_ncm.c", "drivers/usb/gadget/function/u_ether.c", "drivers/usb/gadget/function/u_ether.h", "drivers/usb/gadget/function/u_ncm.h"], "versions": [{"version": "3.11", "status": "affected"}, {"version": "0", "lessThan": "3.11", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.176", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.143", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.19", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.9", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.1.176"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.6.143"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.12.78"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.18.19"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "6.19.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.11", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/7c97366f5dac5255e60a317ffe3a5b18f3745547"}, {"url": "https://git.kernel.org/stable/c/36c41e9724c9a7a7cda37f5a4e9d94f25c8031c4"}, {"url": "https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4"}, {"url": "https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d"}, {"url": "https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69"}, {"url": "https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0"}], "title": "usb: gadget: f_ncm: Fix net_device lifecycle with device_move", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"x_adpType": "supplier", "providerMetadata": {"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-10-15T01:19:23.793Z"}, "affected": [{"vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [{"status": "affected", "version": "0", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}], "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}]}]}}

{}

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This\nresults in a regression where the DHCP server fails on pmOS.\n\nUse device_move to reparent the net_device between the gadget device and\n/sys/devices/virtual/ across bind/unbind cycles. This preserves the\nnetwork interface across USB reconnection, allowing the DHCP server to\nretain their binding.\n\nIntroduce gether_attach_gadget()/gether_detach_gadget() helpers and use\n__free(detach_gadget) macro to undo attachment on bind failure. The\nbind_count ensures device_move executes only on the first bind.\n\n[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/\n[2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nusb: gadget: f_ncm: Correcci\u00f3n del ciclo de vida de net_device con device_move\n\nEl dispositivo de red sobrevivi\u00f3 a su dispositivo gadget padre durante la desconexi\u00f3n, lo que result\u00f3 en enlaces sysfs colgantes y problemas de desreferencia de puntero nulo.\n\nUn intento anterior de resolver esto eliminando SET_NETDEV_DEV por completo [1] fue revertido debido a preocupaciones sobre el orden de la gesti\u00f3n de energ\u00eda y una regresi\u00f3n de NO-CARRIER.\n\nUn intento posterior de aplazar la asignaci\u00f3n de net_device a bind [2] rompi\u00f3 el mapeo 1:1 entre la instancia de funci\u00f3n y el dispositivo de red, haciendo imposible que configfs informara el nombre de interfaz resuelto. Esto resulta en una regresi\u00f3n donde el servidor DHCP falla en pmOS.\n\nUtilizar device_move para reasignar el padre del net_device entre el dispositivo gadget y /sys/devices/virtual/ a trav\u00e9s de los ciclos de bind/unbind. Esto preserva la interfaz de red a trav\u00e9s de la reconexi\u00f3n USB, permitiendo que el servidor DHCP retenga su enlace.\n\nSe introducen las funciones auxiliares gether_attach_gadget()/gether_detach_gadget() y se utiliza la macro __free(detach_gadget) para deshacer la conexi\u00f3n en caso de fallo de bind. El bind_count asegura que device_move se ejecute solo en el primer bind.\n\n[1] https://lore.kernel.org/lkml/f2a4f9847617a0929d62025748384092e5f35cce.camel@crapouillou.net/\n[2] https://lore.kernel.org/linux-usb/795ea759-7eaf-4f78-81f4-01ffbf2d7961@ixit.cz/"}], "id": "CVE-2026-43421", "lastModified": "2026-11-11T20:10:00.273", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2026-05-08T15:16:54.173", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/36c41e9724c9a7a7cda37f5a4e9d94f25c8031c4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7c97366f5dac5255e60a317ffe3a5b18f3745547"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0"}, {"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: usb: gadget: f_ncm: Fix net_device lifecycle with device_move", "id": "2468230", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2468230"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["A flaw was found in the Linux kernel's USB gadget function for Network Control Model (NCM). During device disconnection, a network device could outlive its parent gadget device, leading to dangling system file system (sysfs) links and null pointer dereference problems. This vulnerability can result in a system crash, causing a Denial of Service (DoS)."], "name": "CVE-2026-43421", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-08T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-43421\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43421\nhttps://lore.kernel.org/linux-cve-announce/2026050847-CVE-2026-43421-82b4@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[40d133d7f542616cf9538508a372306e626a16e9,93f116c3393a22acab96ad1bef12b2572eb80ca4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[40d133d7f542616cf9538508a372306e626a16e9,e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[40d133d7f542616cf9538508a372306e626a16e9,85acaba2f42b557499bab3608307f17bf13beb69)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[40d133d7f542616cf9538508a372306e626a16e9,ec35c1969650e7cb6c8a91020e568ed46e3551b0)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "3.11"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,3.11)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.78,6.13.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.19,6.19.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.19.9,6.20.0]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-05-08T18:15:13.670443+00:00", "updated": "2026-05-26T15:30:08.834836+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}