{"id":"CVE-2024-26996","summary":"usb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: Fix UAF ncm object at re-bind after usb ep transport error\n\nWhen ncm function is working and then stop usb0 interface for link down,\neth_stop() is called. At this piont, accidentally if usb transport error\nshould happen in usb_ep_enable(), 'in_ep' and/or 'out_ep' may not be enabled.\n\nAfter that, ncm_disable() is called to disable for ncm unbind\nbut gether_disconnect() is never called since 'in_ep' is not enabled.\n\nAs the result, ncm object is released in ncm unbind\nbut 'dev-\u003eport_usb' associated to 'ncm-\u003eport' is not NULL.\n\nAnd when ncm bind again to recover netdev, ncm object is reallocated\nbut usb0 interface is already associated to previous released ncm object.\n\nTherefore, once usb0 interface is up and eth_start_xmit() is called,\nreleased ncm object is dereferrenced and it might cause use-after-free memory.\n\n[function unlink via configfs]\n  usb0: eth_stop dev-\u003eport_usb=ffffff9b179c3200\n  --\u003e error happens in usb_ep_enable().\n  NCM: ncm_disable: ncm=ffffff9b179c3200\n  --\u003e no gether_disconnect() since ncm-\u003eport.in_ep-\u003eenabled is false.\n  NCM: ncm_unbind: ncm unbind ncm=ffffff9b179c3200\n  NCM: ncm_free: ncm free ncm=ffffff9b179c3200   \u003c-- released ncm\n\n[function link via configfs]\n  NCM: ncm_alloc: ncm alloc ncm=ffffff9ac4f8a000\n  NCM: ncm_bind: ncm bind ncm=ffffff9ac4f8a000\n  NCM: ncm_set_alt: ncm=ffffff9ac4f8a000 alt=0\n  usb0: eth_open dev-\u003eport_usb=ffffff9b179c3200  \u003c-- previous released ncm\n  usb0: eth_start dev-\u003eport_usb=ffffff9b179c3200 \u003c--\n  eth_start_xmit()\n  --\u003e dev-\u003ewrap()\n  Unable to handle kernel paging request at virtual address dead00000000014f\n\nThis patch addresses the issue by checking if 'ncm-\u003enetdev' is not NULL at\nncm_disable() to call gether_disconnect() to deassociate 'dev-\u003eport_usb'.\nIt's more reasonable to check 'ncm-\u003enetdev' to call gether_connect/disconnect\nrather than check 'ncm-\u003eport.in_ep-\u003eenabled' since it might not be enabled\nbut the gether connection might be established.","modified":"2026-04-02T10:06:41.045717Z","published":"2024-05-01T05:28:16.652Z","related":["MGASA-2024-0263","MGASA-2024-0266","SUSE-SU-2024:1979-1","SUSE-SU-2024:1983-1","SUSE-SU-2024:2008-1","SUSE-SU-2024:2019-1","SUSE-SU-2024:2135-1","SUSE-SU-2024:2184-1","SUSE-SU-2024:2190-1","SUSE-SU-2024:2203-1","SUSE-SU-2024:2973-1","SUSE-SU-2025:20008-1","SUSE-SU-2025:20028-1","SUSE-SU-2025:20166-1","SUSE-SU-2025:20249-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26996.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0588bbbd718a8130b98c54518f1e0b569ce60a93"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6334b8e4553cc69f51e383c9de545082213d785e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7250326cbb1f4f90391ac511a126b936cefb5bb7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7f67c2020cb08499c400abf0fc32c65e4d9a09ca"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f356fd0cbd9c9cbd0854657a80d1608d0d732db3"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EZ6PJW7VOZ224TD7N4JZNU6KV32ZJ53/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DAMSOZXJEPUOXW33WZYWCVAY7Z5S7OOY/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GCBZZEC7L7KTWWAS2NLJK6SO3IZIL4WW/"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26996.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-26996"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6b4012a2e4d4702f8fb0ee1db1c0f0b17ab7d41b"},{"fixed":"7f67c2020cb08499c400abf0fc32c65e4d9a09ca"},{"fixed":"0588bbbd718a8130b98c54518f1e0b569ce60a93"},{"fixed":"f356fd0cbd9c9cbd0854657a80d1608d0d732db3"},{"fixed":"7250326cbb1f4f90391ac511a126b936cefb5bb7"},{"fixed":"6334b8e4553cc69f51e383c9de545082213d785e"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-26996.json"}}],"schema_version":"1.7.5"}