{"api_version":"1","generated_at":"2026-05-13T02:12:06+00:00","cve":"CVE-2026-43421","urls":{"html":"https://cve.report/CVE-2026-43421","api":"https://cve.report/api/cve/CVE-2026-43421.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43421","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43421"},"summary":{"title":"usb: gadget: f_ncm: Fix net_device lifecycle with device_move","description":"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/","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-08 15:16:54","updated_at":"2026-05-12 14:10:27"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4","name":"https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d","name":"https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0","name":"https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69","name":"https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43421","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43421","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 40d133d7f542616cf9538508a372306e626a16e9 93f116c3393a22acab96ad1bef12b2572eb80ca4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 40d133d7f542616cf9538508a372306e626a16e9 e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 40d133d7f542616cf9538508a372306e626a16e9 85acaba2f42b557499bab3608307f17bf13beb69 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 40d133d7f542616cf9538508a372306e626a16e9 ec35c1969650e7cb6c8a91020e568ed46e3551b0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.78 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.19 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.9 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"43421","cve":"CVE-2026-43421","epss":"0.000180000","percentile":"0.047270000","score_date":"2026-05-12","updated_at":"2026-05-13 00:11:53"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","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"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"93f116c3393a22acab96ad1bef12b2572eb80ca4","status":"affected","version":"40d133d7f542616cf9538508a372306e626a16e9","versionType":"git"},{"lessThan":"e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d","status":"affected","version":"40d133d7f542616cf9538508a372306e626a16e9","versionType":"git"},{"lessThan":"85acaba2f42b557499bab3608307f17bf13beb69","status":"affected","version":"40d133d7f542616cf9538508a372306e626a16e9","versionType":"git"},{"lessThan":"ec35c1969650e7cb6c8a91020e568ed46e3551b0","status":"affected","version":"40d133d7f542616cf9538508a372306e626a16e9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","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"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.11"},{"lessThan":"3.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.78","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.19","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.78","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.19","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.9","versionStartIncluding":"3.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"3.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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/"}],"providerMetadata":{"dateUpdated":"2026-05-11T22:24:15.807Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43421","datePublished":"2026-05-08T14:21:56.363Z","dateReserved":"2026-05-01T14:12:56.008Z","dateUpdated":"2026-05-11T22:24:15.807Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-08 15:16:54","lastModifiedDate":"2026-05-12 14:10:27","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43421","Ordinal":"1","Title":"usb: gadget: f_ncm: Fix net_device lifecycle with device_move","CVE":"CVE-2026-43421","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43421","Ordinal":"1","NoteData":"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/","Type":"Description","Title":"usb: gadget: f_ncm: Fix net_device lifecycle with device_move"}]}}}