{"id":"CVE-2026-43421","revision":"d7a413df4dca489cae1940e73e085ba0","records":[{"revision":"d7a413df4dca489cae1940e73e085ba0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-43421","aliases":[],"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":0,"publishedAt":"2026-05-08T14:21:56.363+00:00","modifiedAt":"2026-10-15T01:19:23.793+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/usb/gadget/function/f_ncm.c\",\n                        \"drivers/usb/gadget/function/u_ether.c\",\n                        \"drivers/usb/gadget/function/u_ether.h\",\n                        \"drivers/usb/gadget/function/u_ncm.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"40d133d7f542616cf9538508a372306e626a16e9\",\n                            \"lessThan\": \"7c97366f5dac5255e60a317ffe3a5b18f3745547\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"40d133d7f542616cf9538508a372306e626a16e9\",\n                            \"lessThan\": \"36c41e9724c9a7a7cda37f5a4e9d94f25c8031c4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"40d133d7f542616cf9538508a372306e626a16e9\",\n                            \"lessThan\": \"93f116c3393a22acab96ad1bef12b2572eb80ca4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"40d133d7f542616cf9538508a372306e626a16e9\",\n                            \"lessThan\": \"e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"40d133d7f542616cf9538508a372306e626a16e9\",\n                            \"lessThan\": \"85acaba2f42b557499bab3608307f17bf13beb69\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"40d133d7f542616cf9538508a372306e626a16e9\",\n                            \"lessThan\": \"ec35c1969650e7cb6c8a91020e568ed46e3551b0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/usb/gadget/function/f_ncm.c\",\n                        \"drivers/usb/gadget/function/u_ether.c\",\n                        \"drivers/usb/gadget/function/u_ether.h\",\n                        \"drivers/usb/gadget/function/u_ncm.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.11\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.11\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.176\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.143\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.78\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.19\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.9\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/7c97366f5dac5255e60a317ffe3a5b18f3745547","https://git.kernel.org/stable/c/36c41e9724c9a7a7cda37f5a4e9d94f25c8031c4","https://git.kernel.org/stable/c/93f116c3393a22acab96ad1bef12b2572eb80ca4","https://git.kernel.org/stable/c/e584cb58a2ea7ff4d3a4bc43d5ca512ed3ecb77d","https://git.kernel.org/stable/c/85acaba2f42b557499bab3608307f17bf13beb69","https://git.kernel.org/stable/c/ec35c1969650e7cb6c8a91020e568ed46e3551b0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43421","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-43421","identifiers":["CVE-2026-43421"]},"retained":false,"historicalAffected":[]}],"coverage":[]}