{"id":"CVE-2026-31617","revision":"2c8566a27ac54d5fabe759c02af58f69","records":[{"revision":"2c8566a27ac54d5fabe759c02af58f69","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31617","aliases":[],"title":"usb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ncm: validate minimum block_len in ncm_unwrap_ntb()\n\nThe block_len read from the host-supplied NTB header is checked against\nntb_max but has no lower bound. When block_len is smaller than\nopts->ndp_size, the bounds check of:\n\tndp_index > (block_len - opts->ndp_size)\nwill underflow producing a huge unsigned value that ndp_index can never\nexceed, defeating the check entirely.\n\nThe same underflow occurs in the datagram index checks against block_len\n- opts->dpe_size.  With those checks neutered, a malicious USB host can\nchoose ndp_index and datagram offsets that point past the actual\ntransfer, and the skb_put_data() copies adjacent kernel memory into the\nnetwork skb.\n\nFix this by rejecting block lengths that cannot hold at least the NTB\nheader plus one NDP.  This will make block_len - opts->ndp_size and\nblock_len - opts->dpe_size both well-defined.\n\nCommit 8d2b1a1ec9f5 (\"CDC-NCM: avoid overflow in sanity checking\") fixed\na related class of issues on the host side of NCM.","state":0,"publishedAt":"2026-04-24T14:42:36.191+00:00","modifiedAt":"2026-10-15T01:17:13.982+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                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"068a7f2749fff6462a0a908ec415b885fe430f50\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"1425655c2870054c3ab4712e2b6dbdd331597ada\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"8b3b7bd3c02f98634baaf36c7fc7ac915f6517ca\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"0f156bb5334e588034ca68ac2ee92b23f66e56e7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"8757a2593631443648218244b9788e193ae0fdc1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"6762f8a95772265dd0c2ffe7f400493f3115b135\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"d58ba8f6546232f8414f396c189297dbee03f1a7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"74908b0318d1df1188457040b8714ff4d4b68126\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"2b74b0a04d3e9f9f08ff026e5663dce88ff94e52\",\n                            \"lessThan\": \"8f993d30b95dc9557a8a96ceca11abed674c8acb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f7e0611e207d8908c4f2858e244370529a76dbf7\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"b88ad6e714284b33a47834f5f2a294c2b37c66aa\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"471b23586387a32857778c511be60ab31c98dcfd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4f529c4d1e436230d3af7c09a3239677a14d2b46\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"ae6a5394d9fbe118bc95cfe376d6a9d91d7547e8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"4.9.235\",\n                            \"lessThan\": \"4.10\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.14.196\",\n                            \"lessThan\": \"4.15\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"4.19.143\",\n                            \"lessThan\": \"4.20\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.4.62\",\n                            \"lessThan\": \"5.5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.8.6\",\n                            \"lessThan\": \"5.9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\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                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.9\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.9\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.258\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.209\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.175\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.136\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.83\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.24\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.14\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.1\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/068a7f2749fff6462a0a908ec415b885fe430f50","https://git.kernel.org/stable/c/1425655c2870054c3ab4712e2b6dbdd331597ada","https://git.kernel.org/stable/c/8b3b7bd3c02f98634baaf36c7fc7ac915f6517ca","https://git.kernel.org/stable/c/0f156bb5334e588034ca68ac2ee92b23f66e56e7","https://git.kernel.org/stable/c/8757a2593631443648218244b9788e193ae0fdc1","https://git.kernel.org/stable/c/6762f8a95772265dd0c2ffe7f400493f3115b135","https://git.kernel.org/stable/c/d58ba8f6546232f8414f396c189297dbee03f1a7","https://git.kernel.org/stable/c/74908b0318d1df1188457040b8714ff4d4b68126","https://git.kernel.org/stable/c/8f993d30b95dc9557a8a96ceca11abed674c8acb"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31617","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31617","identifiers":["CVE-2026-31617"]},"retained":false,"historicalAffected":[]}],"coverage":[]}