{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-26996",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "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->port_usb' associated to 'ncm->port' 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->port_usb=ffffff9b179c3200\n  --> error happens in usb_ep_enable().\n  NCM: ncm_disable: ncm=ffffff9b179c3200\n  --> no gether_disconnect() since ncm->port.in_ep->enabled is false.\n  NCM: ncm_unbind: ncm unbind ncm=ffffff9b179c3200\n  NCM: ncm_free: ncm free ncm=ffffff9b179c3200   <-- 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->port_usb=ffffff9b179c3200  <-- previous released ncm\n  usb0: eth_start dev->port_usb=ffffff9b179c3200 <--\n  eth_start_xmit()\n  --> dev->wrap()\n  Unable to handle kernel paging request at virtual address dead00000000014f\n\nThis patch addresses the issue by checking if 'ncm->netdev' is not NULL at\nncm_disable() to call gether_disconnect() to deassociate 'dev->port_usb'.\nIt's more reasonable to check 'ncm->netdev' to call gether_connect/disconnect\nrather than check 'ncm->port.in_ep->enabled' since it might not be enabled\nbut the gether connection might be established."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "1da177e4c3f4",
                                            "version_value": "7f67c2020cb0"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.15.157",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.1.88",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.6.29",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.8.8",
                                                        "lessThanOrEqual": "6.8.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.9",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/7f67c2020cb08499c400abf0fc32c65e4d9a09ca",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/7f67c2020cb08499c400abf0fc32c65e4d9a09ca"
            },
            {
                "url": "https://git.kernel.org/stable/c/0588bbbd718a8130b98c54518f1e0b569ce60a93",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/0588bbbd718a8130b98c54518f1e0b569ce60a93"
            },
            {
                "url": "https://git.kernel.org/stable/c/f356fd0cbd9c9cbd0854657a80d1608d0d732db3",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/f356fd0cbd9c9cbd0854657a80d1608d0d732db3"
            },
            {
                "url": "https://git.kernel.org/stable/c/7250326cbb1f4f90391ac511a126b936cefb5bb7",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/7250326cbb1f4f90391ac511a126b936cefb5bb7"
            },
            {
                "url": "https://git.kernel.org/stable/c/6334b8e4553cc69f51e383c9de545082213d785e",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/6334b8e4553cc69f51e383c9de545082213d785e"
            }
        ]
    },
    "generator": {
        "engine": "bippy-9e1c9544281a"
    }
}